Microstimulation applied to the trigeminal motor nucleus (NVmt), the reticular border zone surrounding the NVmt, the parvocellular reticular formation or the Nucleus reticularis pontis caudalis (NPontc) elicited a postsynaptic potential in 81% of the neurons tested for synaptic inputs. 
In rostral and lateral areas, increments occurred bilaterally in the borderzones surrounding the trigeminal motor nucleus (Regio h); the rostrodorsomedial half of the trigeminal main sensory nucleus; subnucleus oralis-gamma of the spinal trigeminal tract; nuclei reticularis parvocellularis pars alpha and Nucleus reticularis pontis caudalis (RPc) pars alpha.
The amygdala sends heavy and broad projections to the rostral midbrain including the periaqueductal gray (PAG), the deep layers of the superior colliculus/deep mesencephalic nucleus (deep SC/DpMe), and the lateral mesencephalic reticular formation (MRF) that in turn project to the Nucleus reticularis pontis caudalis (PnC), an obligatory relay in the primary acoustic startle circuit.
Such control is mediated via cervical reticulospinal neurons (C-RSNs), which take origin in the Nucleus reticularis pontis caudalis and nucleus reticularis gigantocellularis, and give off multiple collaterals along the full length of their axonal trajectory.
Neurons of the dorsal Nucleus reticularis pontis caudalis (nPontc) fire rhythmically during fictive mastication, while neurons of the ventral half tend to fire tonically (Westberg et al., 2001).
CRNs project, among other targets, to the Nucleus reticularis pontis caudalis (PnC), a major component of the ASR circuit, but little is known about the organization of this projection.
The nucleus reticularis pontis oralis (RPO) and Nucleus reticularis pontis caudalis (RPC) are implicated in the generation of rapid eye movement sleep (REM).
Sixty-seven neurons in Nucleus reticularis pontis caudalis (nPontc), nucleus reticularis parvocellularis (nParv), and nucleus reticularis gigantocellularis (Rgc) were studied.
We performed a theory-driven directed search for activity in the Nucleus reticularis pontis caudalis, situated in the pons.
The aim of the present study was to evaluate the effects of unilateral microinjections of competitive and non-competitive NMDA antagonists, 2-amino-7-phosphonoheptanoic acid (AP-7) and dizocilpine (MK-801), respectively, into the Nucleus reticularis pontis caudalis of the rat PRF upon seizures induced by PTZ (70 mg/kg i.p.).
A large number of labeled cells were found in the Nucleus reticularis pontis caudalis (RP) of the pontomedullary junction and in the nucleus reticularis gigantocellularis (Rgc), parvocellularis (Rpc), subtrigiminalis (Rst), paragigantocellularis (Rpg) and paramedianus (RpaM) in the medulla.
The auditory startle reaction to an unexpected loud stimulus is regarded as a brainstem reflex originating in the Nucleus reticularis pontis caudalis and being distributed up the brainstem and down the spinal cord along slowly conducting pathways.
Deposits of the retrograde tracer Fluoro-Gold into the ventrolateral Nucleus reticularis pontis caudalis labeled neurons in the deep layers of the superior colliculus/mesencephalic reticular formation (deep SC/Me).
The role of the Nucleus reticularis pontis caudalis (NRPC) and the nucleus reticularis gigantocellularis (NRG) in control of vertical and oblique head orienting movements was investigated in alert cats by lesion of these nuclei with kainic acid.
The dorsal cochlear nucleus (DCN) has been shown to project to a region of the Nucleus reticularis pontis caudalis (PnC) critical for the evocation of startle in rats, suggesting a possible modulatory influence of the DCN on startle.
Unilateral local infusion of corticotropin-releasing hormone (CRH; 0, 10, 20, 40 and 80 ng) into the Nucleus reticularis pontis caudalis (PnC), an obligatory synapse in the acoustic startle reflex, significantly elevated startle amplitude in a dose-dependent manner.
The influence of both structures may be mediated by anatomical connections with the acoustic startle circuit, perhaps at the level of the Nucleus reticularis pontis caudalis.
In contrast, injections into the Nucleus reticularis pontis caudalis (NRPc), nucleus reticularis gigantocellularis (NRGc), and nucleus reticularis magnocellularis (NRMc) resulted in bilateral labelling--primarily in areas 6a beta, 6a gamma, and in the rostromedial region of area 4--with little labelling in the proreus cortex.
A very high degree of correlation was observed between theta waves in nucleus reticularis pontis oralis, hippocampal fields and Nucleus reticularis pontis caudalis; sometimes r approached unity.
(1982) proposed a primary acoustic startle circuit in rats consisting of the auditory nerve, posteroventral cochlear nucleus, an area near the ventrolateral lemniscus (VLL), Nucleus reticularis pontis caudalis (PnC), and spinal motoneurons.
The 9 other cell populations belonged to the lateral group and extended from the posterior mesencephalic tegmentum to the caudal rhombencephalon [ formatio reticularis mesencephali, nucleus ventrolateralis tegmenti, ectopic area (Ec) of the nucleus isthmo-opticus (NIO), nucleus subceruleus, nucleus ceruleus, Nucleus reticularis pontis caudalis, nucleus vestibularis medialis, nucleus reticularis parvocellularis and nucleus reticularis magnocellularis].
The prearcuate cortex projects to several brainstem areas which also receive projections from the caudal fastigial nucleus, including the supraoculomotor periaqueductal gray matter, superior colliculus, medial nucleus reticularis tegmenti pontis, dorsomedial basilar pontine nucleus, dorsolateral basilar pontine nucleus, Nucleus reticularis pontis caudalis, pontine raphe, and nucleus prepositus hypoglossi.
Rats were implanted with cannulas in the Nucleus reticularis pontis caudalis (PnC), an obligatory part of the neural pathway that mediates the acoustic startle reflex.
The acoustic startle reflex in rats and cats is mediated primarily by a small cluster of giant neurons in the ventrocaudal part of the Nucleus reticularis pontis caudalis (RPC) of the reticular formation.
In the monkey, excitatory burst neurons were confirmed to the Nucleus reticularis pontis caudalis and did not extend farther rostrally into the nucleus reticularis pontis oralis. The putative excitatory burst neuron area in man is in the medial part of the Nucleus reticularis pontis caudalis (extending 2.5 mm mediolaterally), immediately rostral (250 microns) to the omnipause neurons and extending 2.2 mm rostrally, and the putative inhibitory burst neuron area lies in the medial part of the paragigantocellular nucleus caudal to the abducens nucleus, extending 1.8 mm caudally.
Of these, 120 neurons were recorded in the pontine reticular formation, chiefly in the Nucleus reticularis pontis caudalis, and the remaining 116 were in the medullary reticular formation, chiefly in the nucleus reticularis gigantocellularis.
The brain stem of rats was transected at the middle of the Nucleus reticularis pontis caudalis.
The early postoperative effects of lesions, aimed to destroy the caudal pole of the nucleus reticularis pontis oralis (NRPO) and the rostral pole of the Nucleus reticularis pontis caudalis (NRPC), were tested in freely moving cats, walking at moderate speed (0.4-1.0 m/s).
The present study examined the role of excitatory amino acid receptors at the level of the Nucleus reticularis pontis caudalis, a brainstem nucleus obligatory for the whole body startle reflex and implicated as the locus where extrinsic systems such as the amygdala may act to modulate acoustic startle. Twenty-nine rats, chronically implanted with bilateral cannulae aimed at the Nucleus reticularis pontis caudalis, were tested to assess the effects of gamma-D-glutamylglycine (DGG), DL-2-amino-5-phosphonopentanoic acid (AP5), and 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) on the amplitude of the acoustic startle reflex. These results suggest that, at the level of the Nucleus reticularis pontis caudalis, an excitatory amino acid neurotransmitter may mediate acoustic startle, and that both NMDA and non-NMDA receptor subtypes may be important for the expression of the acoustic startle reflex..
The effective sites corresponded to the dorsomedial part of both the nucleus reticularis pontis oralis (NRPo) and the rostral portion of the Nucleus reticularis pontis caudalis (NRPc).
The results argue in favor of a reduced excitability of the Nucleus reticularis pontis caudalis from which a reticulospinal tract emanates as effector of the audiospinal facilitation.
They were bilateral and involved the area of the Nucleus reticularis pontis caudalis, left medial lemniscus and roots of several cranial nerves, especially the VIth.
Using an extracellular recording technique, those common interneurons were identified as reticulospinal neurons by showing axonal projection to C2-3 spinal segment; they were also found to distribute mainly to the medial region of the Nucleus reticularis pontis caudalis immediately rostral to the abducens nucleus, and not in the medullary reticular formation caudal to the abducens nucleus.
In the lower brain stem, stem axons of type Ib and Ic neurones passed in the dorsal part of the reticular formation or in the medial longitudinal fasciculus and projected collaterals to the dorsal part of the Nucleus reticularis pontis caudalis (NRPC) and the nucleus reticularis gigantocellularis (NRG) and the reticular formation underlying the nucleus prepositus hypoglossi (PH) and the raphe region.
Stimulation of ipsilateral FFH induced negative field potentials of several hundred microvolts with the latency of about 1.1 ms in the medial ponto-medullary reticular formation, being largest in the ventral part of the Nucleus reticularis pontis caudalis (NRPC), and in the dorsal part of the nucleus reticularis gigantocellularis (NRG).
Following implantation of HRP pellets into the spinal gray matter (C1-C3) or in the ponto-medullary reticular formation, the Nucleus reticularis pontis caudalis (NRPC) or in the nucleus reticularis gigantocellularis (NRG), numerous neurones were retrogradely labelled in FFH on the ipsilateral side.
In the present study, the anterograde tracer Phaseolus vulgaris-leucoagglutinin was used to identify and delineate the course of a direct projection from the central nucleus of the amygdala to the Nucleus reticularis pontis caudalis, a nucleus in the acoustic startle circuit.
Mercury staining was first detected after 10 days in cell bodies of five specific areas of the brain stem: the mesencephalic nucleus of the trigeminal nerve, the red nuclei, the ventral cochlear nucleus, the superior vestibular nucleus, and the Nucleus reticularis pontis caudalis.
Rolipram increased startle responses that were elicited by brief electrical stimulation of the ventral cochlear nucleus or Nucleus reticularis pontis caudalis, two brainstem relay nuclei of the startle neural circuit.
The Nucleus reticularis pontis caudalis (NRPC) cannot be considered as an head startle relay intercalated between the ventral nucleus of the lateral lemniscus (VNLL) and the medial bulbar reticular formation (MBRF) because mean latencies of field potentials in the pontine RF and the LL nucleus are the same (2.3 ms).
Because the acoustic startle pathway is organized in a serial fashion, startle can be elicited electrically with progressively shorter latencies by stimulating different points along this pathway [ i.e., ventral cochlear nucleus (VCN), paralemniscal zone (PLZ), Nucleus reticularis pontis caudalis (RPC) or medial longitudinal fasciculus (MLF)].
Patients with unilateral gaze palsy had lesions in the paramedian area of the pons, including the abducens nucleus, the lateral part of the Nucleus reticularis pontis caudalis and the nucleus reticularis pontis oralis.
In addition to the restricted distribution of labeled Purkinje cells in lobules VI and VII of the posterior lobe vermis ("oculomotor vermis"), retrogradely labeled cells were present in the dorsolateral pontine nucleus (DLPN), dorsomedial pontine nucleus (DMPN), nucleus reticularis tegmenti pontis (NRTP), pontine raphe (PR), paramedian Nucleus reticularis pontis caudalis (NRPC), nucleus prepositus hypoglossi (NPH), subnucleus b of the medial accessory olivary nucleus (sbMAO), and vestibular complex (VC).
Projections of reticulospinal neurones (RSNs) in the Nucleus reticularis pontis caudalis (N.r.p.c.) to dorsal neck motoneurones supplying splenius (SPL, lateral head flexor) and biventer cervicis and complexus (BCC, head elevator) muscles were studied in the cat anaesthetized with pentobarbiturate or alpha-chloralose.
The mRSNs were located in a fairly localized region corresponding to the Nucleus reticularis pontis caudalis (N.r.p.c), while inRSNs, 1RSNs and coRSNs were mainly in the nucleus reticularis gigantocellularis (N.r.g.), in the nucleus reticularis magnocellularis (N.r.m.) and in the nucleus reticularis ventralis (N.r.v.).
Projection of single neurons in the Nucleus reticularis pontis caudalis (NRPC) to the gray matter of the hindlimb segments was examined by mapping thresholds of antidromic activation.
Acoustic startle is a short-latency reflex mediated by a neural circuit consisting of the ventral cochlear nucleus (VCN), ventral nucleus of the lateral lemniscus (VLL), the Nucleus reticularis pontis caudalis (RPC), and the spinal cord.
It also partially depressed startle elicited by electrical stimulation of the Nucleus reticularis pontis caudalis (RPC).
More caudally, numerous neurons were labelled in the contralateral abducens nucleus and the vestibular complex and a few in the Nucleus reticularis pontis caudalis.
In the present study, we have examined the acute and chronic motor effects of injecting ibotenic acid (IBO) into the nucleus reticularis pontis oralis, Nucleus reticularis pontis caudalis and rostral medullary nucleus gigantocellularis of the feline PMRF. However, lesions including the Nucleus reticularis pontis caudalis (NRPC) produced more severe and persistent HM deficits than those including the nucleus reticularis gigantocellularis.
Based upon retrograde HRP labeling, the principal afferents to the VTN region of the cmPRF originated from the medial and lateral mammillary nuclei, and lateral habenular nucleus, and to a lesser extent from the interpeduncular nucleus, lateral hypothalamus, dorsal tegmental nucleus, superior central nucleus, and contralateral Nucleus reticularis pontis caudalis.
Intracellularly recorded neurones in Nucleus reticularis pontis caudalis of the medial pontine reticular formation (mPRF) in the in vitro slice preparation were analysed for repetitive firing properties in response to intracellularly applied constant-current pulses.
Four groups of 8 adult male hooded rats of the Long-Evans strain were investigated before and after bilateral symmetric lesions of the Nucleus reticularis pontis caudalis (RPC) in a Y-maze and in a jump test box.
A population of reticulospinal neurons with short latency response to startle-inducing stimuli was identified in the Nucleus reticularis pontis caudalis (NRPC) and nucleus gigantocellularis (NRGC) of the medial pontomedullary reticular formation.
A localized lesion was made in the Nucleus reticularis pontis caudalis (NRPC) and the nucleus reticularis gigantocellularis (NRG) by kainic acid injection, and its effects on visually triggered orienting eye and head movements in the horizontal direction were investigated in alert head-free cats.
Cases with injections into the caudal medial pontine tegmentum (Nucleus reticularis pontis caudalis, NRPC), including the physiological paramedian pontine reticular formation (PPRF), but not NRTP, contained the largest number of labeled cells in the fastigial nucleus (FN) and lacked retrograde labeling in the DN.
With these techniques, we have been able to demonstrate that in addition to pontine reticular cells, many cells in the dorsolateral pontine tegmentum, including the LC-complex, project their axons to the rostral part of the midline DTF area, and that descending axons from the nucleus reticularis pontis oralis pass through the DTF area and terminate on cells in the Nucleus reticularis pontis caudalis and the nucleus reticularis gigantocellularis.
In three experiments, startle responses to brief intense tone-bursts (30 msec, 110 dB, 6000 Hz) and single pulse (0.1 msec) stimulation of the cochlear nucleus and the Nucleus reticularis pontis caudalis are studied under high pressures of heliox (from 0 bar to 50 bars) in the rat.
Such neurones were found in the Nucleus reticularis pontis caudalis, being distributed in the area extending 0.8-3 mm rostral to the rostral pole of the abducens nucleus, 1.3-2.7 mm deep from the dorsal surface of the brain stem, and 0.8-1.8 mm lateral from the midline.
While the afferentation of the rostral portion of the Nucleus reticularis pontis caudalis appears to conform to the general pattern outlined above, some deviations from that pattern emerge when the innervation of the caudal district of the Nucleus reticularis pontis caudalis is considered; the most striking of these differences is the fact that both spinal and cerebellar inputs seem to distribute much more heavily to the referred caudal district than to the remaining magnocellular pontine reticular formation.
Subconvulsant doses of strychnine increased startle elicited acoustically or electrically through either the VCN or the Nucleus reticularis pontis caudalis (RPC), pointing to a spinal locus of action of strychnine after systemic administration.
These cells constituted less than 2% of the cells tested in this region and were distributed throughout several nuclei in the medulla and pons including Nucleus reticularis pontis caudalis, nucleus reticularis gigantocellularis, and the border between nucleus reticularis paramedianus and nucleus interfascicularis hypoglossi.
Sixty rats were implanted with bilateral electrodes in the ventral cochlear nucleus (VCN), ventral acoustic stria (VAS), dorsal lateral lemniscus (DLL), ventral lateral lemniscus (VLL), or the Nucleus reticularis pontis caudalis (RPC).
Six of them, Group I, received unilateral lesions in ventral and lateral areas of the nucleus reticularis pontis oralis (RPO) and rostral Nucleus reticularis pontis caudalis (RPC).
Neuronal responses of two reticular structures--Nucleus reticularis pontis caudalis (RPC) and nucleus reticularis gigantocellularis (RGC)--to electrical nociceptive stimulation of the internal intercostal nerve and non-nociceptive, tactile stimulation of the skin in the same somatic area have been studied in chloralose anesthetized cats.
The major input sources to the pause neuron region were nucleus prepositus hypoglossi, medial vestibular nucleus, gigantocellular reticular nucleus, parvocellular reticular nucleus, nucleus reticularis tegmentis pontis, Nucleus reticularis pontis caudalis, nucleus reticularis pontis oralis, and superior colliculus.
Lesions directed at pretectal nuclei, superficial layers of the superior colliculus, thalamic reticular nucleus, Nucleus reticularis pontis caudalis or dorsal nucleus of the lateral lemniscus did not attenuate potentiated startle.
Retrogradely-labeled cells were found in lateral reticular nucleus of the medulla, nucleus raphe magnus, Nucleus reticularis pontis caudalis, locus ceruleus, dorsal and ventral parabrachial nuclei, substantia nigra and the lateral hypothalamus.
The second is the Nucleus reticularis pontis caudalis.
Efferent vestibular neurons were found in the Nucleus reticularis pontis caudalis bilaterally with more cells ipsilateral to the injection side, while efferent cochlear neurons could be demonstrated medial to the ventral division of the facial nucleus bilaterally with more neurons contralateral to the injection..
Bilateral lesions of ventral regions of the Nucleus reticularis pontis caudalis, which contain cell bodies that give rise to the reticulospinal tract, abolish acoustic startle. In contrast, lesions of the dorsal cochlear nuclei, vestibular nuclei, nucleus reticularis pontis oralis, nucleus reticularis gigantocellularis, and dorsal regions of the Nucleus reticularis pontis caudalis fail to abolish acoustic startle. The data suggest that a primary acoustic startle circuit in the rat consists of auditory nerve, ventral cochlear nucleus, nuclei of the lateral lemniscus, Nucleus reticularis pontis caudalis, spinal interneuron, lower motor neuron, and muscles.
Fibers originating in the caudal pons (Nucleus reticularis pontis caudalis) terminate relatively heavily in the intralaminar nuclei of the dorsal thalamus, particularly the centre median, central lateral, central dorsal and paracentral nuclei, and also the dorsal medial nucleus.
The second area occurred largely 2-3 mm lateral to the midline, in the area of the Nucleus reticularis pontis caudalis rostrally, and the nuclei reticularis gigantocellularis and parvocellularis caudally.
In another series of studies, the effects of systemically-administered DMT and 5-MeODMT on the "startle" elicited by electrical stimulation of the Nucleus reticularis pontis caudalis (RPC) were determined.
In contrast, arachidonic acid acted most rapidly after administration into the Nucleus reticularis pontis caudalis..
Fluorescent cells were noted intermingled among the HRP-labeled vestibular efferent neurons in the Nucleus reticularis pontis caudalis.
Efferent vestibular neurons were always found within a small portion of the Nucleus reticularis pontis caudalis (RP), ventrolateral to the abducens nucleus on both sides.
Another region for an accumulation of labelled cells is the rostral part of Nucleus reticularis pontis caudalis.
Stimulation of Nucleus reticularis pontis caudalis inhibits triggering of epileptic discharges. The desynchronization elicited by the mesencephalic RF seems to be mostly activating, whereas desynchronization elicited by the Nucleus reticularis pontis caudalis--mostly inhibitory..
zone) or the border zone of the Nucleus reticularis pontis caudalis and the gigantocellularis (R.p.c.-R.gc.
In the pontomedullary reticular formation within 1.5 mm of the midline, antidromically excited neurons were detected in (1) the contralateral abducens nucleus, (2) the contralateral reticular formation just caudal and caudoventral to the abducens nucleus, and (3) the ipsilateral Nucleus reticularis pontis caudalis beneath and rostral to the abducens nucleus.
Using a retrograde tracer technique with microiontophoretically applied horseradish peroxidase (HRP), afferent projections to the brain stem raphe nuclei (BR, raphe magnus, pallidus and obscurus) and to two adjacent reticular nuclei, Nucleus reticularis pontis caudalis (nRPC) and nucleus gigantocellularis (nGC) were identified.
(3) In normal rats, electrical stimulation of the LC was relatively ineffective, compared to stimulation of Nucleus reticularis pontis caudalis, in producing behavioral changes (especially locomotion) or either atropine-resistant or atropine-sensitive hippocampal RSA or neocortical LVFA.
After stereotaxis lexions in the nucleus reticularis gigantocellularis of the modulla oblongata and Nucleus reticularis pontis caudalis, the distribution of degenerating nerve fibers in the lumbar segments of the spinal cord has been studied by silver impregnation methods of Nauta and Fink-Heimer.
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