We found that, in mdx mice, dystrophin is expressed in the amygdala, and that, in the basolateral nucleus (BLA), the numbers of GABA(A) receptor alpha2 subunit clusters are reduced. These results suggest that a deficit of brain dystrophin induces an alteration of amygdala local inhibitory neuronal circuits and enhancement of fear-motivated defensive behaviours in mice.. 
The amygdala is considered crucial in emotional modulation and stronger amygdala reactivity in response to fearful stimuli has been found in carriers of the short (S) allele of the 5-HTT gene in imaging studies. Additionally, reactivity of amygdala-innervated effectory systems is also of particular interest.
OBJECTIVE: To investigate the effects of amygdala kindled seizures on memory retention of passive-avoidance test in rats. METHODS: Chronic kindled seizures were achieved by daily application of electric stimulations on amygdala until the occurrence of 3 consecutive convulsive seizures. Then a passive-avoidance test was performed to measure memory retention ability in rats; another group of rats received an electric stimulation on amygdala 5 min before the training trail to observe the effects of acute seizure attack on memory retention ability. Conclusion: Chronic amygdala kindled seizures increase memory retention of passive-avoidance test in rats, and acute seizure attack impairs this action..
Results Relative to the comparison group, boys with conduct problems and elevated levels of callous-unemotional traits manifested lesser right amygdala activity to fearful faces.
Paradoxically, FAAH levels increased in the hypothalamus and, to a lesser extent, in the prefrontal cortex and the amygdala, but not in the caudate-putamen. By contrast, the levels of CB(1) receptors were markedly reduced in the amygdala and prefrontal cortex of these rats, although no changes were seen in the hypothalamus and the caudate-putamen.
Smelling of unscented air was the baseline condition, also used for measurements of functional connectivity from the amygdala. In CAH women and control women AND activated the anterior hypothalamus, and EST the amygdala, piriform, and anterior insular cortex. Women displayed connections with the contralateral amygdala, cingulate, and the hypothalamus, men with the basal ganglia, the insular and the sensorimotor cortex. Furthermore, the connections were in CAH and control women more widespread from the left amygdala, in men from the right amygdala.
We focused our study in the central nucleus of the amygdala (CeA) because it is implicated in alcohol drinking behavior as well as stress behavior.
RESULTS: We found that the cortical gray matter volume of patients was reduced in the frontotemporal regions including the bilateral cingulate cortex and amygdala. Because the cingulate cortex and amygdala are involved in emotion processing, gray matter loss in these regions may contribute to the development of early behavioral symptoms of SSPE..
amygdala, prefrontal cortex, suprachiasmatic nucleus) in the regulation of the CAR.
The posterodorsal portion of the medial amygdala (MePD) is sexually dimorphic in several rodent species.
Five general brain regions contained retrogradely labeled neurons: cerebral cortex (infralimbic and insular regions), rostral forebrain structures (subfornical organ, organum vasculosum of the lamina terminalis, taenia tecta, nucleus accumbens, lateral septum, endopiriform nucleus, dorsal BST, substantia innominata, and, most prominently the amygdala-primarily its basomedial and central subnuclei), thalamus (central medial, intermediodorsal, reuniens, and, most prominently the paraventricular thalamic nucleus), hypothalamus (medial preoptic area, perifornical, arcuate, dorsomedial, parasubthalamic, and posterior hypothalamic nuclei), and brainstem (periaqueductal gray matter, dorsal and central superior raphe nuclei, parabrachial nucleus, pre-locus coeruleus region, NTS, and A1 noradrenergic neurons in the caudal ventrolateral medulla).
Our data revealed that VEGF is dramatically up-regulated in neurons and glia in hippocampus, thalamus, amygdala, and neocortex 24 h after status epilepticus.
Study A is complemented by 4 interrelated add-on projects focusing on attachment style (study B1), on cost-effectiveness (study B2), on variation in the serotonin transporter gene in SP (study C1) and on structural and functional deviations of the hippocampus and amygdala (study C2).
Next, we evaluate the feasibility of using different lines of thy1::Clomeleon transgenic mice to image synaptic inhibition in several different brain regions: the hippocampus, the deep cerebellar nuclei (DCN), the basolateral nucleus of the amygdala, and the superior colliculus (SC). Similar responses to synaptic activity were observed in DCN neurons, amygdalar principal cells, and collicular premotor neurons.
Dispositional mindfulness has been associated with greater activation in prefrontal cortex and greater deactivation of amygdala during affect labeling.
The serotonin (5-HT) 1A receptor has been found to be dysregulated in prefrontal cortex and other brain regions in schizophrenia, and 5-HT1A receptor levels in the amygdala have been related to negative schizophrenia symptoms.
In the present study, we investigated the effects and interaction of nicotinic and GABAergic systems in the central amygdala of rats, using the elevated plus maze test of anxiety. Bilateral administration of nicotine (1 and 2 mug/rat; 1 mul/rat; 0.5 mul/rat in each side) into the central amygdala (intra-CeA) induced an anxiogenic-like effect, shown by specific decreases in the percentage of open-arm time (%OAT) and percentage of open arm entries (%OAE). It can be concluded that in the central amygdala, the GABAergic system is not involved in the anxiogenic response to nicotine..
The proportion of patients with mixed diagnoses among all cases with Alzheimer disease (AD), vascular pathology (VP), argyrophilic grain dementia (AGD), and synucleinopathies, such as Lewy body dementia (LBD), Parkinson disease (PD) and synuclein pathology only in the amygdala, was 53.3%.
Seven showed signal intensity abnormalities, with prominent involvement of the hippocampus, and six showed additional involvement of the amygdala. Among the seven HHV6-negative patients, six had abnormalities in the hippocampus but only two showed extrahippocampal involvement, which was restricted to the amygdala. Conclusion: Most patients with HHV6 encephalitis have signal intensity abnormalities in the hippocampal formation and amygdala and, contrary to prior reports, some also have involvement of limbic structures outside of the medial temporal lobe.
Although we were unable to replicate past research demonstrating relatively increased amygdala activation among individuals with an "s" allele to negative stimuli, women with an s allele evidenced decreased left fusiform gyrus activation to positive emotional stimuli (as expected).
CRF in the paraventricular nucleus of the hypothalamus (PVN) and CRF in the central nucleus of the amygdala (CeA) are involved in the regulation of stress responses, and gender differences in CRF mRNA expression in these regions in response to various stressors are controversial.
Notably, newborn neurons with a mature neuronal phenotype are found in the olfactory tubercles, anterior olfactory nuclei, tenia tecta, islands of Calleja, amygdala, and lateral entorhinal cortex.
The binding of [ (3)H]CGP 54626 in the nucleus accumbens subareas and the amygdala was decreased by ca.
To determine neuronal activation, the expression of the immediate-early genes c-fos and activity-regulated cytoskeletal associated protein (Arc) was studied in the central nucleus of the amygdala (CeA), bed nucleus stria terminalis (BST) and paraventricular hypothalamic nucleus (PVN), which are areas involved in the neuroendocrine and central stress response.
Apart from common vomeronasal recipient structures in the amygdala, only the anterior accessory olfactory bulb projects to the bed nucleus of the stria terminalis and only the posterior accessory olfactory bulb projects to the dorsal anterior amygdala. These two vomeronasal subsystems mediated by V1R and V2R receptors were partially segregated, not only in amygdala, but also in the hypothalamus..
Recent studies of ERalpha and male prosocial behavior have shown an inverse relationship between ERalpha expression in regions of the brain that regulate social behavior, including the medial amygdala (MeA), and the expression of male prosocial behavior.
Methods: Phenytoin-resistant and phenytoin-non resistant epileptic rats were selected in the amygdala kindled adult male Wistar rats.
Several other regions were labeled including the parts of the amygdala, periaqueductal gray, lateral parabrachial nucleus and deep cerebellar nuclei.
Dopaminergic (DA) inputs to the basolateral nuclear complex of the amygdala (BLC) are critical for several important functions, including reward-related learning, drug-stimulus learning, and fear conditioning. The present study utilized dual-labeling immunohistochemistry at the electron microscopic level to examine DA inputs to pyramidal cells in the anterior basolateral amygdalar nucleus (BLa) in the rat. Thus, using CaMK as a marker, the present study demonstrates that pyramidal cells, especially their distal dendritic compartments, are the primary targets of dopaminergic inputs to the basolateral amygdala..
RESULTS: Hypothesized significant group x valence x referent interactions were observed within regions of the medial prefrontal cortex and bilateral amygdala. CONCLUSIONS: These results implicate the medial prefrontal cortex, involved in the representation of the self, together with the amygdala, in the pathophysiology of GSP.
RESULTS: Compared with controls, patients showed significantly more decline in gray matter density of the hippocampus, anterior cingulum, left amygdala, and right dorsomedial prefrontal cortex. CONCLUSION: This study supports findings from animal studies of neuroplastic stress-related processes that occur in the hippocampus, amygdala, dorsomedial prefrontal cortex, dorsolateral prefrontal cortex, and anterior cingulum during depressive episodes..
DAT binding potentials (BP) were assessed in the hippocampus, amygdala, ventral and dorsal striatum. We found that correlation coefficients between total UPSIT scores and regional brain DAT BP were highest for the hippocampus (Rs=0.54, P=0.002) and lower for the amygdala (Rs=0.44, P=0.02), ventral (Rs=0.48, P=0.008) and dorsal striatum (Rs=0.39, P=0.03). We conclude that selective hyposmia in PD is more robustly correlated with hippocampal rather than amygdala, ventral or dorsal striatal dopamine innervation as shown by DAT binding.
The amygdala and hippocampus were dissected. KEY FINDINGS: Ten days after injection of lidocaine, lipid peroxidation increases in the hippocampus because the ROS are enhanced from day 5, whereas in the amygdala lipid peroxidation and the ROS were enhanced only on the first day postinjection. In the amygdala the GSH and GSSG content were increased at day 10. In the amygdala the lidocaine enhances the activities of catalase and GPX, but no SOD isoenzymes were modified. SIGNIFICANCE: In this research we demonstrated that lidocaine affects the redox environment and promotes increases of the oxidative markers both in the hippocampus and amygdala but in a different pattern..
The central nucleus of the amygdala (CeA), the nociceptive amygdala, serves as the major output nucleus of the amygdala and participates in receiving and processing pain information.
The amygdala has received great interest as a possible neurophysiological substrate of bipolar disorder (BD). This review summarizes information about the structure and function of the amygdala with attention to its role in experienced emotion and mood. We review the evidence for amygdala pathology in psychiatric conditions and discuss the role of the amygdala in BD during development. There appear to be consistent findings in the neuroimaging literature that suggest an etiological model for BD that involves abnormalities in the structure and function of the amygdala, but also depends on the failure of prefrontal cortical regions to modulate amygdala activity.
The amygdala, striatum, and structures within the prefrontal cortex are highly involved in mediating these stages of emotion processing, and evidence indicates that these regions show structural and functional alterations in different types of psychopathology, including anxiety, depression, and autism spectrum disorders.
Using functional magnetic resonance imaging (fMRI), we compared 12 adolescents with Cushing syndrome with 22 healthy control adolescents on amygdala and anterior hippocampus activation during an emotional faces encoding task. Compared to healthy adolescents, patients with Cushing syndrome showed greater left amygdala and right anterior hippocampus activation during successful face encoding. This first study of cerebral function in adolescents with chronic endogenous hypercortisolemia due to Cushing syndrome demonstrates the presence of functional alterations in amygdala and hippocampus, which are not associated with affective or memory impairments.
We review the fMRI data indicating that particular comorbidities of CD/ODD (i.e., mood and anxiety conditions such as childhood bipolar disorder and PTSD) are associated with either increased responsiveness of neural regions implicated in the basic response to threat (e.g., the amygdala) or decreased responsiveness in regions of frontal cortex (e.g., ventromedial frontal cortex) that are implicated in the regulation of the basic threat response. We show that in individuals with psychopathic tendencies, the functioning of the amygdala in stimulus-reinforcement learning and of the ventromedial frontal cortex in the representation of reinforcement expectancies is impaired.
The work has established that dysfunction in the STS region, as well as reduced connectivity between this region and other social brain structures including the fusiform gyrus and amygdala, play a role in the pathophysiology of social perception deficits in autism.
OBJECTIVE: To investigate neural activity in prefrontal cortex and amygdala during bipolar depression. METHODS: Eleven bipolar I depressed and 17 normal subjects underwent functional magnetic resonance imaging (fMRI) while performing a task known to activate prefrontal cortex and amygdala. Within-group contrasts demonstrated significant amygdala activation in the controls and no significant amygdala activation in the bipolar depressed subjects. The amygdala between-group difference, however, was not significant.
A pattern of alpha activity as estimated by sLORETA was shown in the right amygdala, uncus, hippocampus, BA37, insular cortex and orbitofrontal regions during the SPESA condition.
For example, high levels of expression were observed in the avian amygdala and hippocampus, areas which express high levels of CB1 in mammals.
Emotion-specific responses were found after 120 ms in the right anterior areas with right amygdala activation observed only later ( approximately 200 ms).
We have previously found that synaptic pathway from the basolateral amygdala (BLA) to the dentate gyrus (DG) displays N-methyl-d-aspartate (NMDA) receptor-independent form of long-term potentiation (LTP), which should be a valuable model for elucidating neural mechanisms linking emotion and memory.
The cortical (CoA) and the medial (MeA) nuclei of the amygdala are involved in the processing of olfactory information relevant to social recognition in the ewe. Reciprocal projections were observed between the CoA and the MeA and between both nuclei and the basal or the lateral nuclei of the amygdala with the exception of the CoA which does not send inputs to the lateral nucleus.
These included the insula, amygdala, putamen, and supplementary motor area.
Recent studies have shown that nitric oxide (NO) signaling plays a crucial role in memory consolidation of Pavlovian fear conditioning and in synaptic plasticity in the lateral amygdala (LA).
Phosphatidylinositol 3-kinase (PI3K) and its downstream targets, including Akt (also known as protein kinase B, PKB), mammalian target of rapamycin (mTOR), the 70-kDa ribosomal S6 kinase (p70S6k), and the eukaryotic initiation factor 4E (eIF4E)-binding protein 1 (4E-BP1), may play important roles in long-term synaptic plasticity and memory in many brain regions, such as the hippocampus and the amygdala.
Consolidation of new fear memories has been shown to require de novo RNA and protein synthesis in the lateral nucleus of the amygdala (LA). One key question is whether protein synthesis during reconsolidation depends on already existing mRNAs or on synthesis of new mRNAs in the amygdala.
This study assessed the effect of inhibition of the central nucleus of the amygdala (CeA) and drug experience on brain regions underlying footshock-induced reinstatement of morphine-seeking behaviour in rats.
Event-related fMRI analysis time-locked to the occurrence of REMs revealed that the pontine tegmentum, ventroposterior thalamus, primary visual cortex, putamen and limbic areas (the anterior cingulate, parahippocampal gyrus and amygdala) were activated in association with REMs. The activation of the parahippocampal gyrus and amygdala simultaneously with REMs suggests that REMs and/or their generating mechanism are not merely an epiphenomenon of PGO waves, but may be linked to the triggering activation of these areas..
The framework that is proposed for the disorder explains that the compromised functional integrity of the amygdala is the root cause of disturbed affective consciousness. amygdala, with its connections to various cortical and subcortical regions, helps detect a fearful facial expression at the attentional periphery and make it the focus of attention and awareness for enhanced processing. They process fearful stimuli the way normal controls perceive common objects by activating areas responsible for feature based analysis rather than the amygdala and other connected areas.
Further, increases in 5-HT levels in dorsal hippocampus, basolateral amygdala, nucleus accumbens, and striatum were likewise potentiated, and GR205171 similarly facilitated the influence of fluoxetine upon levels of 5-HT, as well as dopamine and noradrenaline.
A recent lesion study suggests that expression of ethanol-conditioned behaviors depends upon an intact amygdala and nucleus accumbens core. In the present experiments, we used site-specific microinfusions of dopamine and NMDA receptor antagonists to examine the roles of accumbens and amygdala in the expression of ethanol conditioned place preference (CPP) in mice. In experiments 1 and 2, a D1/D2/D3 receptor antagonist (flupenthixol) was infused into accumbens or amygdala before testing, whereas experiment 3 used pretest infusions of an NMDA antagonist (AP-5) to examine the role of intra-accumbens NMDA receptors. Dopamine antagonism of accumbens was without effect, but intra-amygdala infusions of flupenthixol blocked CPP expression. Moreover, this effect was dependent upon dopamine antagonism within the basolateral nucleus but not the central nucleus of the amygdala. The present findings suggest that expression of the ethanol-conditioned response depends upon amygdala dopamine and accumbens NMDA receptors. These are the first studies in any species to show a role for amygdala dopamine receptors and the first studies in mice to implicate accumbens NMDA receptors in ethanol-induced conditioned effects.Neuropsychopharmacology advance online publication, 1 October 2008; doi:10.1038/npp.2008.179..
We examined how the brain mediates this process by recording amygdala neural activity while monkeys performed a trace-conditioning task requiring fixation. Different populations of amygdala neurons tracked the positive or negative value of the current state, regardless of whether state transitions were caused by the FP, CSs, or USs. This representation of state value could underlie how the amygdala helps coordinate cognitive, emotional, and behavioral responses depending on the value of one's state..
Using Freesurfer software, the volumes of MT [ hippocampus, amygdala] and DGM [ thalamus, caudate] structures were calculated.
Ambiguous gambles with incomplete probabilistic information induced stronger brain signals than risky gambles in OFC and amygdala, suggesting that the brain's reward system signals the partial lack of information.
In this paper, we review the role of the striatum and amygdala in affective learning and the coding of aversive prediction errors (PEs).
Significantly higher T2-relaxation values, indicating tissue injury, appeared in anxious OSA versus nonanxious OSA subjects in subgenu, anterior, and mid-cingulate, ventral medial prefrontal and bilateral insular cortices, hippocampus extending to amygdala and temporal, and bilateral parietal cortices.
Neurofunctional and neuropathologic studies have implicated the amygdala as a primary brain structure involved in the regulation of emotion. Because one of the cardinal features of bipolar disorder is mood dysregulation, structural and functional amygdala abnormalities identified with neuroimaging may serve as useful disease and treatment response biomarker. Therefore, we conducted a meta-analysis summarizing the literature examining amygdala size obtained from magnetic resonance imaging in bipolar youths and adults. METHOD:: A literature search using the National Institutes of Health's PubMed was conducted to identify published peer-reviewed neuroimaging studies of amygdala size in children, adolescents, and adults with bipolar disorder. RESULTS:: Smaller amygdala volumes were found in children and adolescents with bipolar disorder compared with the control children and adolescents (standardized mean difference -0.74; 95% confidence interval -1.36 to -0.15). amygdala volumes in bipolar adults were not significantly different from the control adults (standardized mean difference 0.20; 95% confidence interval -0.31 to 0.73). CONCLUSIONS:: The results of this meta-analysis suggest that structural amygdala abnormalities are present in bipolar youths but that these structural differences do not seem to be present in bipolar adults. Future studies examining whether structural, functional, and neurochemical amygdala differences between bipolar and control youths may be useful as age-specific biomarkers of illness and treatment response are needed..
In this study, neurogenesis and the proliferation of astrocytes in the subgranular zone of the hippocampus were explored using unilateral amygdala-kindled rats with or without muscimol, a gammaaminobutyric acid a (GABAa) agonist injection into the bilateral anterior thalamic nuclei (AN). Muscimol injection significantly ameliorated the behavioral scores of epilepsy without any significant alteration on the electroencephalography recorded at the stimulated basolateral amygdala, thus suggesting that muscimol injection might affect the secondary generalization, but not the initial discharge itself. The results might indicate the underlying relationships between neurogenesis and epilepsy, that epileptic propagation in unilateral amygdala-kindled rats might go through AN into the contralateral side with subsequent neurogenesis, although further studies need to clarify the hypothesis..
Met-enkephalin immunoreactive neurons were labeled in the caudate-putamen, intermediated part of lateral septum, lateral globus pallidus, intermediated part of lateral septum, hypothalamus, and amygdala of WT mice.
We investigated the possible relationship between several polymorphisms in the serotonin (5-HT) system and amygdala responses to negative facial stimuli in Korean women using functional magnetic resonance imaging. We found increased activations in response to angry facial stimuli in the bilateral amygdala of subjects with the long allele of 5-HTTLPR compared with those with two copies of the short allele. Higher activations in response to sad facial stimuli were found in the bilateral amygdala of subjects with the T/T genotype of 5-HT(2A) SNP rs6311, compared with C allele carriers, and in subjects with the G/G genotype of TPH2 G(-703)T, compared with those with T/T and G/T genotypes. Our results for individuals from an Asian population countered a previous finding for a Caucasian population and identified the moderating role of genetic background in the relationships between these serotonergic gene polymorphisms and amygdala function elicited by negative emotional stimuli..
Male Wistar rats were stereotaxically implanted with a bipolar electrical stimulation electrode in the amygdala.
Male Wistar rats were implanted with guide cannulae in the basolateral amygdala and neostriatum. Intranasal administration of 2 mg/kg of PROG led to an immediate (within 30 min after the treatment) significant increase in the basolateral amygdala dopamine levels. administration of 4 mg/kg of PROG was followed by a delayed significant increase in dopamine, both, in the basolateral amygdala and neostriatum, but smaller in magnitude in comparison to the intranasal treatment. This is the first study to demonstrate dopamine-enhancing effects of PROG, not only in the neostriatum, but also in the basolateral amygdala.
The findings in our patient suggest that she has patent pathways from higher-order visual cortices to autonomic effectors in amygdala or hypothalamus, even though the results of such information processing are not made available to conscious awareness..
BACKGROUND: In a previous study, we found that rhesus monkeys prepared with bilateral lesions of the amygdala failed to acquire fear-potentiated startle to a visual cue. METHODS: In the current experiment, the eight monkeys used in the second part of the original study, four of which had bilateral amygdala lesions and the four control animals, were trained using an auditory cue and tested in the fear-potentiated startle paradigm. RESULTS: Monkeys with essentially complete damage to the amygdala (based on histological analysis) that had retained and expressed fear-potentiated startle to a visual cue learned before the lesion failed to acquire fear-potentiated startle to an auditory cue when training occurred after the lesion. CONCLUSIONS: The results suggest that while the nonhuman primate amygdala is essential for the initial acquisition of fear conditioning, it does not appear to be necessary for the memory and expression of conditioned fear. These findings are discussed in relation to a network of connections between the amygdala and the orbitofrontal cortex that may subserve different component processes of fear conditioning..
Abstract The medial prefrontal cortex (mPFC), hippocampus, and amygdala are implicated in the regulation of affect and physiological processes, including hypothalamic-pituitary-adrenal (HPA) axis function.
Specifically, we show that simple geometric forms containing only downward-pointing V-shapes elicit greater activation of the amygdala, subgenual anterior cingulate cortex, superior temporal gyrus, and fusiform gyrus, as well as extrastriate visual regions, than do presentations of the identical V-shape pointing upward.
At the imaging level, there was a main effect of valence with increased activity in the medial-temporal lobe (amygdala and hippocampus) during both encoding and retrieval of aversive relative to neutral stimuli. Interestingly, older participants presented with relatively decreased amygdalar-hippocampal coupling and increased amygdalar-prefrontal coupling when compared to younger participants. Furthermore, older participants showed increased activation in prefrontal cortices and decreased activation in the amygdala when contrasting the retrieval of aversive and neutral scenes.
Differential activations to fearful versus neutral faces were observed in the amygdala, pulvinar, and superior colliculus only for faces presented in the left hemifield.
Finally, the results are discussed in terms of a theory of how nicotine could alter hippocampal-cortical-amygdala interactions to facilitate contextual learning..
The model addresses how brain regions responsible for affective learning and habit learning interact and answers a central question: What are the relative contributions of the amygdala and orbitofrontal cortex to emotion and behavior? In the model, the amygdala calculates outcome value while the orbitofrontal cortex influences attention and conditioned responding by assigning value information to stimuli. Interactions of the basal ganglia and amygdala with sensory and orbitofrontal cortices enable the model to replicate the complex pattern of spared and impaired behavioral and emotional capacities seen following lesions of the amygdala and orbitofrontal cortex..
Compared with the control group, the CPP and CPA groups showed a significant increase of c-Fos expression in the dorsomedial striatum, central medial nucleus of the thalamus, and the basolateral amygdala.
The emergence of stereotypies was examined in juvenile rhesus monkeys (Macaca mulatta) who, at 2 weeks of postnatal age, received selective bilateral ibotenic acid lesions of the amygdala (N = 8) or hippocampus (N = 8). However, between 1 to 2 years of age, both amygdala- and hippocampus-lesioned subjects began to exhibit stereotypies. When observed as juveniles, both amygdala- and hippocampus-lesioned subjects consistently produced more stereotypies than the control subjects in a variety of contexts. More interesting, neonatal lesions of either the amygdala or hippocampus resulted in unique repertoires of repetitive behaviors. amygdala-lesioned subjects exhibited more self-directed stereotypies and the hippocampus-lesioned subjects displayed more head-twisting.
Exploratory analyses showed that pretreatment amygdala activity was negatively correlated with change in depressive symptoms.
Stress-induced hypoalgesia (SIH) is an adaptive behavioral phenomenon mediated in part by the amygdala. Acute stress increases amygdalar noradrenaline levels and focal application of alpha(2)-adrenoceptor agonists in the central nucleus of the amygdala (CeA) is antinociceptive.
Here we have examined beta-catenin expression in the adult mouse brain and its role in amygdala-dependent learning and memory. Genetically, the role of beta-catenin was confirmed with site-specific deletions of loxP-flanked Ctnnb1 (encoding beta-catenin) in the amygdala. However, amygdala-specific deletion of Ctnnb1 prevented the normal transfer of newly formed fear learning into long-term memory. Thus, beta-catenin may be required in the amygdala for the normal consolidation, but not acquisition, of fear memory.
We investigated the effect of Rosa damascena Mill, essential oil on the development of induced amygdala kindling seizures. Male Wistar rats were implanted with one tripolar and two monopolar electrodes in right basolateral amygdala and dura surface, respectively.
The maximum level of mRNA expression for corticoliberin was registered in amygdala after the administration of dexamethasone (0.46 units compared to beta-actin), and the minimum level was observed after treatment with sodium ethaminal (0.07) and fentanyl (0.037). Amphetamine activated mRNA expression for corticoliberin neither in hypothalamus nor in amygdala for all of the drugs studied. The mRNA expression for vasopressin was also not registered for all drugs in hypothalamus and amygdala. Therefore, the reinforcing system of hypothalamus supports the typical reaction on the administration of narcotic agents, while the extended amygdala system includes both the proper reinforcement and the stress reactivity elements..
The mammalian telencephalon, which comprises the cerebral cortex, olfactory bulb, hippocampus, basal ganglia, and amygdala, is the most complex and intricate region of the CNS.
Here, we tested the hypothesis that temporal synchronization of theta rhythms among hippocampus, amygdala, and neocortex is related to immediate memorization of repeated words. Spectral coherence of the intracerebral EEG activity was computed in order to assess the temporal synchronization of the theta (about 3-8 Hz) rhythms among hippocampus, amygdala, and temporal-occipital neocortex. We found that theta coherence values between amygdala and hippocampus, and between hippocampus and occipital-temporal cortex, were higher in amplitude during successful than unsuccessful immediate recall. In conclusion, a successful immediate recall to the RAVLT was associated to the enhancement of temporal synchronization of the theta (gamma) rhythms within a cerebral network including hippocampus, amygdala, and temporal-occipital neocortex.
RESULTS: The hallucinating patients showed differential neural activities in various areas including the amygdala, the hippocampus, the cingulate, the prefrontal cortex, and the parietal cortex, compared with the nonhallucinating patients and the normal controls. In particular, compared with the nonhallucinators, the hallucinators revealed reduced activation in the left amygdala and the bilateral hippocampus during the processing of crying sounds. CONCLUSION: Our findings suggest that the persistence of AHs in schizophrenia may induce functional disturbances of the emotion-related interconnected neural networks, including reduced responsiveness in the amygdala and hippocampus to negative stimuli..
Adrenal glucocorticoids have been implicated in the circadian regulation of clock genes expression in peripheral tissues as well as in the control of the rhythms of expression of PER2 in certain limbic forebrain regions, such as the oval nucleus of the bed nucleus of the stria terminalis (BNSTov) and central nucleus of the amygdala (CEA) in rats.
The acute pain and allodynia increased Fos-positive cells in the prefrontal cortex (PFC), basolateral nucleus (BL) and central nucleus of the amygdala (Ce), indicating that these areas are involved in pain processing.
The aims of this study were to investigate NCAM-mediated signaling transduction pathways and the levels of the phosphorylated (Ser133) active form of the CREB in the brain structures (the pre- and frontal cortex, basolateral amygdala, and hippocampus) involved in the memory formation in NCAM-deficient mice. Immunohistochemical analysis revealed reduced levels of pCREB in the prefrontal cortex (PFC), frontal cortex (FC), CA3 subregion of the hippocampus (CA3) and basolateral nucleus of amygdala (BLA) in NCAM-/- mice.
Results identified two separable pathways that together explained approximately 50% of the reported variance in self-reported emotion: (1) a path through nucleus accumbens that predicted greater reappraisal success, and (2) a path through ventral amygdala that predicted reduced reappraisal success (i.e., more negative emotion).
use a novel mediation analysis of neuroimaging data to show two independent pathways for the control of emotion by the prefrontal cortex: a path through the amygdala predicts a greater negative emotional response, and a path through the nucleus accumbens/ventral striatum predicts a greater positive response..
NMDA receptor-dependent long-term potentiation (LTP) of glutamatergic synaptic transmission in sensory pathways from auditory thalamus or cortex to the lateral amygdala (LA) underlies the acquisition of auditory fear conditioning.
However, studies of progressive change in deep brain nuclei and hippocampal-amygdala formation have not yielded consistent findings. Large-deformation high-dimensional brain mapping was used to generate surfaces for deep brain nuclei and hippocampal-amygdala formation at baseline and follow-up. RESULTS: The pattern of progressive changes in the deep brain nuclei and hippocampal-amygdala formation in schizophrenia and control subjects was variable. Of the structures that receive direct projections from the cortex, the thalamus, caudate nucleus, nucleus accumbens, and hippocampus showed changes specific to subjects with schizophrenia, and changes in the amygdala and putamen were similar in both groups.
RESULTS: Binding potential of [ (11)C]doxepin in female subjects was significantly higher than that in male subjects at the following brain sites: amygdala, hippocampus, medial prefrontal cortex, orbitofrontal cortex, and temporal cortex. Anorexia nervosa patients showed significantly higher BP of [ (11)C]doxepin in the amygdala and lentiform nucleus than the control female subjects. In AN patients, BP of [ (11)C]doxepin in the amygdala and thalamus negatively correlated with EAT-26 scores. There was a significant negative correlation between BP of [ (11)C]doxepin and SDS or STAI scores in the amygdala, anterior cingulate cortex, and orbitofrontal cortex of AN patients. CONCLUSIONS: These findings support the hypothesis that women have higher H1R density in the limbic system than men and suggest that AN patients may have higher expression of H1R in the limbic brain, particularly in the amygdala..
RESULTS AND DISCUSSION: In WT mice, LY341495 induced widespread c-Fos expression in 68 out of 92 brain areas, including limbic areas such as the amygdala, septum, prefrontal cortex, and hippocampus. LY341495-induced c-Fos response was markedly decreased in the medial part of the central amygdala (CeM) and lateral septum (LS) in mGlu3-KO mice, as well as in the lateral parabrachial nucleus (LPB) in both KO strains.
Hyper-activation of the amygdala, a brain region involved in fear, to facial stimuli may be an important underlying neural abnormality.
In this study, we examined the role of actin polymerization in lateral amygdala (LA) in fear conditioning memory formation.
[ 1] demonstrated that in different stages PD pathology involves the nigrostriatal system, the amygdala, and the insular cortex.
The present research found that prejudiced attitudes of ingroup favoritism were associated with amygdala, medial and right lateral orbitofrontal cortex.
Furthermore, the magnitude of positive mood change correlated negatively with DPN binding in the amygdala bilaterally.
The posterodorsal medial amygdala (MePD) is a sex steroid-responsive area in the rat brain.
Expression of the dopamine D1-receptor transcript was elevated in the amygdala and decreased in the hippocampus while the transcript level of the dopamine D4-receptor was increased in the nucleus accumbens.
In combination with previous research on these strains, the present data tentatively suggest that Fast and Slow animals utilize different neural systems in tests of fear and anxiety which may have been co-selected with the direct selection of amygdala-kindling susceptibility..
The limbic system (comprising the amygdala and the anterior cingulate cortex) and the prefrontal cortex (the orbital and dorsolateral prefrontal cortices) have been implicated in emotional and behavioral control. Selective lesion studies in rodents suggest that the basolateral nucleus of the amygdala, which is a critical subnucleus within the amygdala, plays a critical role in appetitive instrumental behaviors. On the other hand, the central nucleus of the amygdala directly receives afferents from the lateral nucleus of the amygdala. These 2 nuclei (central and lateral) of the amygdala are implicated in the learning of reflexive behavior (e.g., orienting, startle, and approaching behaviors) and autonomic responses (e.g., heart rate and blood pressure) during pavlovian conditioning.
Volumetric MRI scans from 26 women with repeated episodes of childhood sexual abuse and 17 healthy female comparison subjects (ages 18-22 years) were analyzed for sensitive period effects on hippocampal and amygdala volume, frontal cortex gray matter volume and corpus callosum area.
Simple regression analysis revealed significant age-related increases in relative metabolic values in the parahippocampal and amygdala regions in both sexes in their twenties to forties, and significant age-related decreases in both sexes in their fifties to seventies.
Selection of high, relative to low, reward magnitude increased activity in insula, amygdala, middle and posterior cingulate cortex, and basal ganglia.
Cases with visual hallucinations showed a greater degree of atrophy of the cucullar nucleus, possibly due to amygdala denervation.
A test of the interaction between derogatory emotion and its self-directedness revealed significant activation of the amygdala. Our findings indicate an important role of the amygdala in the processing of unpleasant emotion or self-relevance of information in the real world may also be expanded to the processing of self-directedness of unpleasant emotion in the imagined world, and thereby contribute to human higher social cognitive process.
Correlation coefficients of the anterior cingulate-primary sensorimotor, posterior cingulate-primary sensorimotor and occipital-media frontal in both hemispheres, of the frontal-primary sensorimotor, occipital-parahippocampal, primary visual-medial frontal and parahippocampal-amygdala in the right, and the frontal-vermis, parietal-thalamus, temporal-vermis, occipital-putamen, primary visual-putamen, thalamus-vermis and thalamus-cerebellum in the left were significantly different in patients compared with controls.
The perception of and memory for faces, with or without emotional content, were studied in 43 patients with temporal lobe epilepsy who had undergone unilateral resection of the hippocampus and the amygdala and in 43 healthy participants for comparison.
There were no associations between t-tau and p-tau(181) with dementia severity and only weak correlations between t-tau and cerebral glucose metabolism (superior parietal gyrus, r = -0.325, P < 0.05; precentral gyrus r = -0.418, P < 0.01; amygdala r = -0.362, P < 0.05).
Correlated well with the reduced anxiety, expression of GABA(A)alpha(1) receptor was higher whereas c-Fos was lower in the cortex, hippocampus, and amygdala of the mice expressing PS2 mutation than those of the wild-type PS2 or nontransgenic control mice.
Its role in important brain structures such as the midbrain, the lateral septal complex, the hypothalamus, the olfactory bulb, the pons, the choroid plexus, the nucleus pallidus, the striatum and the amygdala, the nucleus accumbens and the anterior cingulated gyrus candidate it as a promising target for genetic association studies.
The results showed various brain activations, predominantly in the amygdala in the early phase, the medial frontal cortex and the occipitotemporal junction in the middle phase, and the thalamus in the late phase, which correlated with a subject's proneness to hallucinating.
Results: Mean (18)F-FCWAY V/f1, compared with normal controls, was decreased significantly in fusiform gyrus, hippocampus, and parahippocampus ipsilateral to epileptic foci, and AIs were significantly greater in hippocampus, parahippocampus, fusiform gyrus, amygdala, and inferior temporal regions.
Stress and anxiety are mainly regulated by amygdala and hypothalamic circuitries involving several neurotransmitter systems and providing physiological responses to peripheral organs via the hypothalamic-pituitary-adrenal axis and other pathways. These behavioral data are supported by an approximal 30% reduction in corticotropin-releasing hormone (CRH) mRNA expression in the hypothalamic paraventricular nucleus and central amygdala and an accompanying 30-40% decrease in corticosterone serum levels in prodynorphin knockout mice.
Clinical manifestations were compatible with the behavioral variant of frontotemporal dementia and included motor neuron symptoms; there was prominent neuronal loss in the frontal and temporal cortex, subiculum, and amygdala.
A general pattern emerged of cortical regions covarying inversely with subcortical structures, particularly the frontal cortex with cerebellum, amygdala and thalamus.
In this study, we investigated the effects of intraperitoneal (i.p.) injection of opioid drugs on responses induced by intracentral amygdala (intra-CeA) microinjection of cannabinoid CB1 receptor agents in rats, using the elevated plus maze test of anxiety.
We found a significant effect of gender on brain activations in the left amygdala and right temporal pole, where females demonstrated increased activations over males.
Because these behaviors require threat assessment of the environment, it is plausible that they are regulated by the amygdala-associated neural circuitry of fear. However, the amygdala is not a single anatomic and functional unit, and nuclei of the amygdala have multiple inter- and intra-connections. This poses a question as to the exact role of different amygdala nuclei in these behaviors and the mechanisms involved. The basolateral complex of the amygdala nuclei (BLA) is particularly interesting in this regard: although the BLA role in forming memories for learned fear is established, the BLA role in innate behaviors is not well understood.
The autopsy of three of them showed neuronal loss, microgliosis, and cytotoxic T cell infiltrates in the hippocampus and amygdala.
Animal studies have highlighted orbital and medial prefrontal cortex and amygdala as mediators of operant extinction. Functional connectivity analysis demonstrated inverse connectivity between frontopolar OFC and both rACC and the amygdala. These data support animal models suggesting the importance of mOFC-amygdala interaction during operant extinction and expand our knowledge of the neural systems in humans. These findings suggest that in humans, frontopolar OFC modulates activity in caudal mOFC, rACC and amygdala during successful operant extinction learning..
amygdala, ventral striatum, and tectum.
A specific pattern was encountered in the MTLE subgroup, consisting of a BP(ND) decrease involving hippocampus, amygdala and temporal pole altogether. All TLE patients with [ (18)F]MPPF BP(ND) decreases involving hippocampus, amygdala and temporal pole together, with or without extension to the ipsilateral insula, were good candidates for anterior temporal lobectomy.
Since activity in the lateral amygdala (LA) seems crucial for fear expression of behavior, we studied the mechanisms of NPY in LA projection neurons using whole-cell patch-clamp recordings in slices of the rat amygdala in vitro. Functionally, the dampening of excitability in projection neurons of the amygdala may contribute to the decrease in anxiogenic behavior during action of NPY..
Here, we demonstrate that in addition to increasing anxiety, early-weaning manipulations alter the accumulation of galactosylceramide, a specific myelin constituent, and the axonal structure of myelinated fibers in the amygdala of male Balb/c mice. Lipid analysis of mice amygdalas showed the early accumulation of galactosylceramide in early-weaned male, but not female, mice at 5 weeks. The precocious accumulation of galactosylceramide was observed only in the amygdala; galactosylceramide accumulation was not observed in the prefrontal cortex or hippocampus of early-weaned male mice. Electron microscopy showed an increase in the number and a decrease in the diameter of myelinated axons in the anterior part of the basolateral amygdala in early-weaned male mice at 5 weeks. These results suggest that the higher anxiety levels observed in early-weaned male mice could be related to precocious myelin formation in the anterior part of the basolateral amygdala..
The neural circuit comprising the VTA-accumbens-PFC-amygdala is activated by brief episodes of social stress, which is critical for the DA-mediated behavioral sensitization and increased stimulant consumption.
Familiar speakers and direct addressing evoked significantly stronger amygdala activation than unfamiliar speakers and neutral phrases.
The mesiotemporal lobe is involved in decision making processes because bilateral amygdala damage can cause impairments in decision making that is mainly based on the processing of emotional feedback. In the current study, we investigated whether unilateral mesiotemporal damage, comprising of the hippocampus and/or the amygdala, results in alterations of both kinds of decision making. Furthermore, disadvantageous decision making can emerge in patients with selective hippocampal sclerosis not extended to the amygdala. Thus, our results demonstrate for the first time that presurgical patients with TLE can have selective reductions in decision making and that these deficits can result from hippocampal lesions without structural amygdala abnormalities..
We sought to examine the changes in hippocampal and amygdala volumes at baseline and at 3 years after an acute depressive episode, and the impact of reduced hippocampal volumes on the outcome. METHODS: In a prospective, longitudinal study, we examined the hippocampus and amygdala of 30 inpatients with major depression from the Department of Psychiatry and Psychotherapy and 30 healthy participants from the community (control group) using high-resolution magnetic resonance images at baseline and after 3 years. RESULTS: During the 3-year follow-up period, neither hippocampal nor amygdala volumes changed significantly among patients or participants in the control group.
Independently, the degree of microvacuolation was graded in the entorhinal cortex and the amygdala of the same cases. In pure AD cases microvacuolation was related to senile plaque density, especially in the amygdala, where many of the neuropil vacuoles were around dense-cored, neuritic plaques. In contrast, in AD/LBD microvacuolation correlated with LB density in the entorhinal cortex and amygdala.
We found that the mirror neuron system, the insula and amygdala were more active during emotional expressions, that this circuit is engaged to a greater extent when interacting with one's own child, and that it is correlated with maternal reflective function (a measure of empathy).
The central extended amygdala (EAc) is an ensemble of highly interconnected limbic structures of the anterior brain, and forms a cellular continuum including the bed nucleus of the stria terminalis (BNST), the central nucleus of the amygdala (CeA) and the nucleus accumbens shell (AcbSh).
Our results suggest that the lateral PFC regions engaged by cognitive emotion regulation strategies may influence the amygdala, diminishing fear through similar vmPFC connections that are thought to inhibit the amygdala during extinction.
Source estimation indicated that this distinction was mediated by an anterior medial temporal region including the amygdala and adjacent cortex.
Traumatic (relative to non-traumatic) memories increased neural activity in the amygdala, hippocampus, lateral temporal, retrosplenial, and anterior cingulate cortices.
The amygdala is classically regarded as a detector of potential threat and as a critical component of the neural circuitry mediating conditioned fear responses. However, it has been reported that the human amygdala responds to multiple expressions of emotions as well as emotionally neutral stimuli of a novel, uncertain or ambiguous nature. Thus, it has been proposed that the function of the amygdala may be of a more general art, i.e. as a detector of behaviorally relevant stimuli [ Sander D, Grafman J, Zalla T (2003) The human amygdala: an evolved system for relevance detection. To investigate this putative function of the amygdala, we used event related functional magnetic resonance imaging (fMRI) and a modified Go-NoGo task composed of behaviorally relevant and irrelevant letter and number stimuli. Analyses revealed bilateral amygdala activation in response to letter stimuli that were behaviorally relevant as compared with letters with less behavioral relevance. Our findings support a role for the human amygdala in general detection of behaviorally relevant stimuli..
Sleep deprivation impairs contextual but not cued learned fear, and it has been suggested that this pattern reflects an insensitivity of the amygdala to sleep loss.
In male rodents, testosterone acts in the posterior medial amygdala (MeP) and medial preoptic area (MPOA) to promote mating.
Six weeks later, rats were transcardially perfused with fixative and then their brains were removed for both hamotoxylin-eosine (H&E) staining for histopathology and immunohistochemistry staining for glial fibrillary acidic protein (GFAP) for astrocytic activity and GLYT1 in the cortical dysplastic region and other rostral brain regions involving epileptogenesis such as hippocampus, pyriform cortex, amygdala, thalamus and substantia nigra.
Identification of the temporal horn of the lateral ventricle was followed by resection of the parahippocampal gyrus, the amygdala, and the uncus.
Infusions of CREB antisense into the amygdala prior to training impair memory for aversive tasks, suggesting that the antisense may interfere with CRE-mediated gene transcription and protein synthesis important for the formation of new memories within the amygdala. However, the amygdala also appears to modulate memory formation in distributed brain sites, through mechanisms that include the release of norepinephrine and acetylcholine within the amygdala. In the present experiment, rats received bilateral intra-amygdala infusions of CREB antisense (2 nmol/1 microL) 6 h prior to inhibitory avoidance training. In vivo microdialysis samples were collected from the right amygdala before, during, and following training. In addition, CREB antisense infusions dampened the training-related release of norepinephrine, and to a lesser extent of acetylcholine, in the amygdala. Furthermore, intra-amygdala infusions of the beta-adrenergic receptor agonist clenbuterol administered immediately after training attenuated memory impairments induced by intra-amygdala injections of CREB antisense. These findings suggest that intra-amygdala treatment with CREB antisense may affect processes involved in modulation of memory in part through interference with norepinephrine and acetylcholine neurotransmission in the amygdala..
We studied the roles of the basolateral amygdala (BLA) and the medial prefrontal cortex (mPFC) in learning and relearning to inhibit context conditioned fear (freezing) in extinction.
We recently showed that neonatal odor-shock learning attenuates later life odor fear conditioning and amygdala activity. (14)C 2-DG autoradiographic brain mapping was used to measure training-related activation in amygdala cortical nucleus (CoA), anterior (aPCx), and posterior (pPCx) piriform cortex.
As compared to HC, SPP showed increased neural activity not only in regions involved in emotional processing including left amygdala and insula, as expected from previous reports, but also in the bilateral superior temporal sulcus (STS), a part of the core system for face perception that is involved in the evaluation of expression and personal traits.
Specifically we review recent neuroanatomical studies that implicate inhibitory GABAergic pathways from the prefrontal cortex to the amygdala and additional inhibitory pathways between the amygdala and the sympathetic and parasympathetic medullary output neurons that modulate heart rate and thus heart rate variability.
VD mothers' brains were significantly more responsive than CSD mothers' brains to their own baby-cry in the superior and middle temporal gyri, superior frontal gyrus, medial fusiform gyrus, superior parietal lobe, as well as regions of the caudate, thalamus, hypothalamus, amygdala and pons.
In both groups, region-of-interest analysis revealed no correlation between the magnitude of amygdala or thalamus activation and the reported level of sexual arousal.
In line with previous conditioning studies, differential responses in the amygdala showed a time by stimulus interaction, suggesting rapid adaptation of CS-specific responses.
Here we report that amygdala (AMYG)-projecting VTA DA neurons have brief APs and lack D(2)R agonist (quinpirole; 1 microM) autoinhibition.
In this study, we investigate the latency and selectivity of visually responsive neurons recorded from microelectrodes in the parahippocampal cortex, entorhinal cortex, hippocampus, and amygdala of human subjects during a visual object presentation task. Regional analysis showed significant correlations between latency and selectivity within the parahippocampal cortex, entorhinal cortex, and hippocampus, but not within the amygdala.
Densities of neuritic plaques (NPs) and of neurofibrillary tangles (NFTs) were assessed in several neocortical regions and in the hippocampus, entorhinal cortex, and amygdala. RESULTS: There were differences among the five groups for NP ratings in the entorhinal cortex (p = 0.003), amygdala (p = 0.009), and overall NP (p = 0.014) as well as counts of NPs in all regions examined (p values ranging from 0.009 to 0.04).
Volumes of ventricular compartments, hippocampus, amygdala, thalamus, cerebellum, and regional cortical gray and white matter were dependent variables.
These included a medial to lateral gradient of increased and decreased regional brain volumes in the posterior vermis, amygdala, and hippocampus.
CMR regions, including brainstem reticular formation, amygdala, and cerebral cortex, have extensive connections to numerous brain areas, allowing these regions to participate potentially in many networks.
Within this network, the posteromedial cortical amygdala (PMCo) receives direct projections from the accessory olfactory bulbs and contains a dense population of steroid receptor-containing neurons.
Significantly enhanced activation for men compared with women was revealed in brain areas involved in erotic processing, i.e., the thalamus, the amygdala, and the orbitofrontal and insular cortex, whereas no specific activation for women was found.
Other areas, including the suprachiasmatic nucleus, posterior paraventricular hypothalamic nucleus, posterior paraventricular thalamic nucleus, arcuate nucleus, and central amygdala, did not respond to 3 h sleep deprivation with a significant increase in c-Fos levels.
Imipramine effects were limited to feedback-related regions, whereas phenelzine had additional effects to decrease accumbens GR and central amygdala MR expression.
Two rat SE models were used, the lithium/pilocarpine model and induction of SE by sustained electrical stimulation of the basolateral amygdala (BLA).
Both the nucleus accumbens (NAc) and basolateral amygdala (BLA) contribute to learned behavioral choice.
OBJECTIVE: Trauma-exposed individuals with post-traumatic stress disorder (PTSD) display reduced amygdala and hippocampal size and impaired cognition. METHOD: Twenty-three young women who had experienced severe childhood sexual/physical abuse, diagnosed with DA/DID or PTSD, and 25 healthy control subjects were subjected to 3D structural magnetic resonance imaging of amygdala and hippocampus and a clinical and neuropsychological investigation. RESULTS: Compared with controls, trauma-exposed subjects with PTSD (n = 10) displayed significantly reduced amygdala and hippocampal size and significantly impaired cognition. By contrast, trauma-exposed subjects with DA or DID (n = 13) displayed normal amygdala and hippocampal size and normal cognition. Our results indicate preserved amygdala and hippocampal size and preserved cognition in subjects with these disorders..
There are, however, a number of other more selective procedures for removal of the mesial temporal lobe structures (amygdala, hippocampus, and parahippocampal gyrus) that spare much of the lateral temporal neocortex.
CONCLUSION: While we are at a preliminary stage in understanding the neural circuitry behind emotional processing, there appears to be a top-down regulation of affect with prefrontal systems modulating subcortical structures such as the amygdala and the ventral striatum.
RESULTS: In comparison with controls, both presynaptic and postsynaptic 5-HT(1A) receptor binding was reduced in untreated patients, with the most significant reductions being in the raphe, orbitofrontal cortex, temporal cortex and amygdala.
This study supports the existence and possible disruption of descending influences from the temporal cortex and/or amygdala on brainstem breathing centres in the term newborn..
In both experiments Ginkgo increased Fos-IR in numerous brain regions including the insular cortex and amygdala.
RESULTS: The main centers affected in the NERD-H patients included the secondary somatosensory cortex (SII), primary somatosensory cortex (S1), right prefrontal cortex (PFC), right orbitofrontal cortex (OFC), insular cortex, amygdala, striatum, motor cortex and its supplementary area, and cerebellum cortices, which form part of the matrix controlling emotional, autonomic modulatory responses to pain.
RESULTS: Patients and controls showed significant differences in signal dynamics between excitatory and inhibitory components of the negative feedback loop that controls emotional arousal, specifically between the right amygdala and Brodmann area 9 (BA9), when viewing angry facial expressions (p = 0.002). While the amygdala responses were not significantly different between groups, patients showed significantly lower BA9 activation during the beginning of the response (0.000amygdala) and inhibitory (prefrontal) limbic regions in medicated schizophrenic patients versus healthy controls.
Subsequently, they were subjected to either a single session of the forced swim test or an estimation of serotonergic function in the prefrontal cortex, hippocampus, amygdala and hypothalamus.
Non-epileptic Wistar rats and GAERS were stimulated in basolateral amygdala with 400 muA at 20 min intervals until they reached stage 5 seizures or for a maximum of 36 stimulations.
METHODS: 23 patients with (AD and 23 sex, age, and educational background-matched normal controls (NC group) underwent three-dimensional MRI to measure the hippocampus, amygdala, entorhinal cortex (EC), perirhinal cortex (PC), cornu temporale, and uncus distance in the baseline survey.
Results revealed that stereotyping was underpinned by activity in areas associated with evaluative processing (e.g., ventral medial prefrontal cortex, amygdala) and the representation of action knowledge (e.g., supramarginal gyrus, middle temporal gyrus).
Voice-sensitive temporal cortices, as well as the amygdala, insula, and mediodorsal thalami, reacted stronger to angry than to neutral prosody.
Furthermore, in the right amygdala and the left precuneus, areas previously associated with processing of unpleasant dissonant musical sounds, there was an interaction between the experimental condition and the stimulus type.
Ibotenic acid-induced lesions of the amygdala prevented the acquisition of fear-potentiated startle but, remarkably, did not prevent the expression of fear-potentiated startle when fear conditioning was carried out prior to the lesion.
Reports an error in "Bilateral neurotoxic amygdala lesions in rhesus monkeys (Macaca mulatta): Consistent pattern of behavior across different social contexts" by Christopher J. (The following abstract of the original article appeared in record 2008-03769-001.) Although the amygdala has been repeatedly implicated in normal primate social behavior, great variability exists in the specific social and nonsocial behavioral changes observed in nonhuman primates with bilateral amygdala lesions. This study measured the social behavior of amygdala-lesioned and unoperated rhesus monkeys (Macaca mulatta) in 2 contexts. Across the 2 contexts, amygdala lesions produced a highly consistent pattern of social behavior. In the course of their interactions, amygdala-lesioned monkeys also displayed an earlier decrease in nervous and fearful personality qualities than did controls. The increased exploration and sexual behavior recorded for amygdala-lesioned monkeys in pairs was not found in the 4-member groups. The authors concluded that the amygdala contributes to social inhibition and that this function transcends various social contexts.
In previous studies, the authors found that Narp is selectively induced by morphine withdrawal in the extended amygdala, a group of limbic nuclei that mediate aversive behavioral responses.
Purpose: The purpose of the present investigation was to quantify alterations in GABA(A)receptor density in vivo in rats subjected to amygdala kindling.
Partner faces also activated the insula, amygdala and thalamus.
In theory, detection of threat cues should activate the amygdala independently from allocation of attention. We used fMRI to examine whether the allocation of attention to components of superimposed spider and bird displays modulates amygdala activation. amygdala activation followed a dose-response relationship: Compared to congruent neutral displays (two birds), amygdala activation was most pronounced in response to congruent phobic displays (two spiders) and less but still significant in response to mixed displays (spider and bird) when attention was focused on the phobic component. When attention was focused on the neutral component, mixed displays did not result in significant amygdala activation. This was confirmed in a significant parametric graduation of the amygdala activation in the order of congruent phobic displays, mixed displays with attention focus on the spider, mixed displays with focus on the bird and congruent neutral displays. These results challenge the notion that amygdala activation in response to briefly presented phobic cues is independent from attention..
In the present study, we investigated the effect of direct infusion of MPD into the basolateral nucleus of amygdala (BLA) or the anterior cingulate cortex (ACC) on conditioned fear memory.
Type A comprises lesions confined to the uncus, hippocampus, parahippocampus, and/or amygdala.
PRINCIPAL FINDINGS: Here we describe a Cre-transgenic line that allows reproducible expression of transgenic proteins of choice in a small number of neurons of the adult cortex, hippocampus, striatum, olfactory bulb, subiculum, hypothalamus, superior colliculus and amygdala.
We found that areas previously associated with offensive aggression in adult hamsters, including the ventrolateral hypothalamus, the medial amygdala, and the bed nucleus of the stria terminalis, also showed enhanced c-Fos expression after play fighting.
The negative emotional state that drives such negative reinforcement is hypothesized to derive from dysregulation of key neurochemical elements involved in reward and stress within the basal forebrain structures involving the ventral striatum and extended amygdala. Specific neurochemical elements in these structures include not only decreases in reward neurotransmission, such as decreases in dopamine and opioid peptide function in the ventral striatum, but also recruitment of brain stress systems, such as corticotropin-releasing factor (CRF), in the extended amygdala. Acute withdrawal from all major drugs of abuse produces increases in reward thresholds, increases in anxiety-like responses, and increases in extracellular levels of CRF in the central nucleus of the amygdala. Other components of brain stress systems in the extended amygdala that interact with CRF and may contribute to the negative motivational state of withdrawal include norepinephrine, dynorphin, and neuropeptide Y.
Basolateral amygdala is crucial for COA learning but its importance in COA consolidation remains to be demonstrated. We investigated whether infusion of anisomycin, a protein synthesis inhibitor, in the basolateral amygdala impaired COA consolidation. This suggests that the formation of odor representation, rather than malaise integration, within the amygdala has been disrupted. Control experiments indicated that anisomycin infusion did not affect amygdala functionality and olfactory perception and did not induce cell death in the amygdala. Moreover, anisomycin treatment induced an important decrease (65-70%) of LiCl-induced Fos protein expression in the basolateral and the central nuclei of the amygdala but not in adjacent piriform cortex indicating a reliable and localized protein synthesis inhibition. These findings suggest the pivotal role of the basolateral amygdala, and possibly the central amygdala, in COA memory consolidation..
We find that Rin1 mediates EphA4 endocytosis in postnatal amygdala neurons after engagement of EphA4 with its cognate ligand ephrinB3. Rin1 was shown to suppress synaptic plasticity in the amygdala, a forebrain structure important for fear learning, possibly by internalizing synaptic receptors. We find that the EphA4 receptor is required for synaptic plasticity in the amygdala, raising the possibility that an underlying mechanism of Rin1 function in amygdala is to down-regulate EphA4 signaling by promoting its endocytosis..
Anisomycin, a protein synthesis inhibitor, was infused into the hippocampus, perirhinal cortex, insular cortex, or basolateral amygdala of rats immediately after the sample phase of object or object-in-context recognition memory training. Infusions into the hippocampus or amygdala did not impair object recognition memory. Anisomycin infused into the hippocampus blocked long-term, but not short-term object-in-context recognition memory, whereas infusions administered into the perirhinal cortex, insular cortex, or amygdala did not affect object-in-context recognition memory.
Significant activity was observed in the right ventral anterior cingulate gyrus and the right amygdala in the negative-word/self-reference condition, and in the left amygdala in the positive-word/self-reference condition. The results also suggest that the amygdala is associated with self-referential processing of both positive and negative emotional stimuli..
We measured T2 relaxation time bilaterally in the hippocampus, the amygdala, and the fusiform gyrus. Apart from raised T2 values in the ipsilateral hippocampus, we found increased T2 values in the ipsilateral amygdala.
Analysis of imaging data demonstrates an increase in MRI signal for all the regions of interest selected including the rostral ventromedial medulla, dorsal raphe, periaqueductal grey, medial thalamus, and central amygdala as predicted by the anatomical data, as well as increases in the lateral thalamus, cingulate/retrosplenial and parietal cortex.
The amygdala and the ventral anterior cingulate cortex (ACC) have been implicated in aggression. Two distinct techniques showed that the connectivity between the ventral ACC and the amygdala was strongly correlated with personality, with high reward-drive participants displaying reduced negative connectivity. Furthermore, the direction of this effect was restricted from ventral ACC to the amygdala but not vice versa. The personality-mediated variation in the pathway from the ventral anterior cingulate cortex to the amygdala provides an account of why signals of aggression are interpreted as provocative by some individuals more than others..
Nucleus accumbens shell, basolateral or lateral amygdala, in this regard, did not seem to be involved in retrieval of the MA-CPP memory.
Neuroimaging studies have shown that altered decision-making in addiction is associated with abnormal functioning of a distributed neural network critical for the processing of emotional information, and the experience of "craving", including the VMPC, the amygdala, the striatum, the anterior cingulate cortex, and the insular/somato-sensory cortices, as well as non-specific neurotransmitter systems that modulate activities of neural processes involved in decision-making. We conclude that there are at least two underlying types of dysfunction where emotional signals (somatic markers) turn in favor of immediate outcomes in addiction: (1) a hyperactivity in the amygdala or impulsive system, which exaggerates the rewarding impact of available incentives, and (2) hypoactivity in the prefrontal cortex or reflective system, which forecasts the long-term consequences of a given action..
Several brain structures, including the medial preoptic area (mPOA), the ventromedial nucleus of the hypothalamus (VMH), the amygdala (Me), and the nucleus accumbens (Acb) have been implicated in the control of female sexual behavior.
In contrast, delayed rewards evoked hyperactivation in dorsal caudate nucleus and amygdala of ADHD patients. Hyperactivation during delayed reward processing, gradually increasing along the ventral-to-dorsal extension of the caudate nucleus, and especially the concomitant hyperactivation of the amygdala are in accordance with predictions of the delay aversion hypothesis..
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