Abducens neurons in the lagging group but not those in the leading group were activated by antidromic stimulation of the contralateral oculomotor nucleus. 
Benedikt syndrome is a rare but debilitating constellation of symptoms that manifests from infarction of the red nucleus, cerebral peduncle, oculomotor fascicles, and lower oculomotor nucleus.
Three different excitatory tracts could be involved in the transmission of upward vestibular eye movement (VEM) signals and upward eye position (EP) signals to the oculomotor nucleus (III): the medial longitudinal fasciculus (MLF), the brachium conjunctivum (BC), and the crossing ventral tegmental tract (CVTT).
Neurophysiol., 67: 944-960] while neurons in the central MRF, the cMRF, located ventral to the SOA and lateral to the oculomotor nucleus are associated with conjugate eye movements [ Waitzman, D.M.
However, choline acetyl transferase staining reveals a single paired column of cells dorsal to the oculomotor nucleus, suggesting the EW is not subdivided.
Motoneurons of the oculomotor nucleus subserving multiply innervated muscle fibres (MIF) receive different afferent inputs from the motoneurons subserving singly innervated muscle fibres (SIF).
NPR-C immunoreactivity was detected in several regions, including the periaqueductal gray, oculomotor nucleus, red nucleus and trochlear nucleus of the midbrain; the pontine nucleus, dorsal tegmental nucleus, vestibular nucleus, locus coeruleus, trigeminal motor nucleus, nucleus of the trapezoid body, abducens nucleus and facial nucleus of the pons; and the dorsal motor nucleus of the vagus, hypoglossal nucleus, lateral reticular nucleus, nucleus ambiguus and inferior olivary nucleus of the medulla oblongata. Interestingly, NPR-C immunoreactivity was detected in the cholinergic neurons of the oculomotor nucleus, trochlear nucleus, dorsal tegmental nucleus, motor trigeminal nucleus, facial nucleus, dorsal motor nucleus of the vagus, nucleus ambiguus and hypoglossal nucleus.
C-RFaimmunoreactive perikarya were observed in the olfactory bulb, the area ventralis telencephali pars dorsalis and lateralis, nucleus preopticus, nucleus preopticus periventricularis, nucleus lateralis tuberis pars posterioris, nucleus posterioris periventricularis, nucleus ventromedialis thalami, nucleus posterioris thalami, nucleus anterior tuberis, the oculomotor nucleus, nucleus reticularis superior and inferior, facial lobe, and vagal lobe.
sGnRH and cGnRH-II antisera revealed immunoreactivity in the perikarya of the olfactory bulbs, preopticus-periventricular nucleus, oculomotor nucleus and midbrain tegmentum.
In a previous study we have shown that the dendrites of oculomotor neurons form bundles which invade the trochlear nucleus, and vice versa, trochlear dendritic bundles invade the oculomotor nucleus.
In turn, it projects to the ipsilateral oculomotor nucleus and lateral nucleus of the valvula.
A high density of alpha(2A)-AR immunoreactivity was found in the ventral telencephalic area, preoptic, pretectal, hypothalamic areas, torus semicircularis, oculomotor nucleus (NIII), locus coreruleus (LC), medial raphe, medial octavolateralis nucleus (MON), magnocellular octaval nucleus (MaON), reticular formation (SRF, IMRF, IRF), rhombencephalic nerves and roots (DV, V, VII, VIII, X), and cerebellar Purkinje cell layer.
It was suggested that the pathway to contralateral downgaze neurons could have been damaged due to the unilateral (left) dosal midbrain lesion before its decussation with the unilateral interstitial nucleus of Cajal, the oculomotor nucleus and the rostral interstitial nucleus of the medial longitudinal fasciculus.
For the first time, the MIF motoneurons could be identified around the medial aspect of the human oculomotor nucleus as a group of ChAT-positive neurons that lack CSPG-positive perineuronal nets.
Since CSX eliminates all sympathetic control of the pupil, and transection of the brain stem at the mid-pontine level blocks access of vagus-induced activity that ascends to the oculomotor nucleus in the midbrain, we conclude that ESV produces PD, at least in part, via inhibition of output from the (parasympathetic) oculomotor nucleus..
We also confirmed that a large number of ChAT-positive motor neurons in the oculomotor nucleus, facial nucleus, hypoglossal nucleus, and spinal motor neurons contained FGF1.
Third nerve palsies can result from lesions located anywhere from the oculomotor nucleus to the termination of the third nerve in the extraocular muscles within the orbit, and may be the herald manifestation of underlying neurological emergencies such as intracranial aneurysm, pituitary apoplexy, and giant cell arteritis.
We have used in vitro slice preparation to investigate the contribution of membrane properties to firing properties of Wistar rat oculomotor nucleus Mns.
NPR-A-immunoreactive perikarya were found in the red nucleus and the oculomotor nucleus in the midbrain, the parabrachial nucleus and the locus coeruleus in the pons, and the dorsal motor nucleus of the vagus, the hypoglossal nucleus, the cuneate nucleus, the gracile nucleus, the nucleus ambiguus, the lateral reticular nucleus, the reticular formation, and the inferior olivary nucleus in the medulla oblongata. Extensive networks of immunoreactive fibers were apparent in the red nucleus, the oculomotor nucleus, the principal sensory trigeminal nucleus, and the parabrachial nucleus.
The purpose of this study was to investigate whether neuronal activity within the oculomotor nucleus could be driving the abnormal cross-axis eye movements observed in the nonfixating eye. METHODS: Burst-tonic activity was recorded from oculomotor nucleus neurons in three animals with A-pattern exotropia as they performed horizontal or vertical smooth pursuit during monocular viewing.
The Nflm and neighboring oculomotor nucleus contain about 600 neurons in total, and among them as many as 500 were labeled retrogradely by an intraspinal tracer implantation and 400 neurons showed glutamatergic immunoreactivity. Furthermore, we confirmed that the caudal part of Nflm and the rostral part of the oculomotor nucleus overlap rostrocaudally by approximately 200 mum.
Anterogradely labeled terminals were present in the ipsilateral area pretectalis pars dorsalis, optic tectum and corpus cerebelli, the bilateral ventromedial thalamic nucleus, lateral valvular nucleus, oculomotor nucleus and inferior olive, and the contralateral periventricular pretectal nucleus.
The present study suggests that the principal sensory trigeminal nucleus projects to the bilateral ventromedial thalamic nucleus, periventricular pretectal nucleus, stratum album centrale of the optic tectum, caudomedial region of lateral preglomerular nucleus, ventrolateral nucleus of semicircular torus, medial part of rostral and posterior lateral valvular nucleus, oculomotor nucleus, trochlear nucleus, trigeminal motor nucleus, facial motor nucleus, superior and inferior reticular formation, descending trigeminal nucleus, medial funicular nucleus, inferior olive, and to the contralateral sensory trigeminal nucleus.
Most of the c-LVST neurons were also activated antidromically from the oculomotor nucleus, suggesting that they are closely related to the control of combined eye-head movements..
Some of the structures showing prominent mMOR-1B4-LI include the olfactory bulb, cerebral cortex, bed nucleus of stria terminalis, hippocampus, habenular nucleus, amygdala, thalamus, hypothalamus, medium eminence, substantia nigra, ventral tegmental area, oculomotor nucleus, red nucleus, raphe nuclei, periaqueductal gray, locus coeruleus, trigeminal nucleus, reticular formation, area postrema and Purkinje cell layer and deep nuclei of cerebellum.
Until now, no similar systematic study has been performed in motoneurons of the oculomotor nucleus. This work has two main aims: first, to determine whether the physiological changes in oculomotor nucleus motoneurons follow a similar time course for different parameters; and second, to compare the temporal sequence with that in other neuronal populations. We recorded the electrophysiological properties of 134 identified oculomotor nucleus motoneurons from 1 to 40 days postnatal in brain slices of rats.
Labeled terminals were also found bilaterally in the oculomotor nucleus, trochlear nucleus, trigeminal motor nucleus, facial motor nucleus, facial lobe, descending trigeminal nucleus, medial funicular nucleus, and contralateral sensory trigeminal nucleus and inferior olive. Labeled terminals in the oculomotor nucleus and trochlear nucleus showed similar densities on both sides of the brain.
To establish whether neurons that participate in the vestibulo-ocular reflex (VOR) have distinct intrinsic physiological properties, oculomotor nucleus (OMN)-projecting neurons were identified in mouse brainstem slices by fluorescent retrograde labeling from the oculomotor complex and targeted for patch-clamp recordings.
The belly injections labeled the medial rectus muscle subgroup of the oculomotor nucleus or the greatest part of abducens nucleus, including some cells outside the medial border of abducens nucleus. The overall identification of multiply-innervated muscle fiber and singly-innervated muscle fiber motoneurons within the rat oculomotor nucleus, trochlear nucleus, and abducens nucleus revealed that the smaller multiply-innervated muscle fiber motoneurons tend to lie separate from the larger diameter singly-innervated muscle fiber motoneurons.
The subgroups are topographically organized in the oculomotor nucleus (III) and are usually considered to form the final common pathway for eye muscle control. The MIF motoneurons lie around the periphery of the oculomotor nucleus (III), trochlear nucleus (IV), and abducens nucleus (VI), slightly separated from the SIF subgroups.
In the present electron microscopic study, we have found that terminals of SVN origin established symmetric synaptic contacts in the oculomotor nucleus. The types of synaptic contacts and distribution of terminals of SVN origin were similar to those found in the oculomotor nucleus.
Using the oculomotor system-and more precisely the abducens internuclear neurons-as a model, we describe herein the effects of disconnecting a population of central neurons from its natural target (i.e., the medial rectus motoneurons at the mesencephalic oculomotor nucleus).
In this case the crossing fibers toward the contralateral superior rectus may have been selectively involved by a tinny lesion in the area of the oculomotor nucleus.
VAMP2 immunoreactivity decreased by 94.4% in the oculomotor nucleus (the first synaptic relay) and by 62.1% presynaptic to abducens neurons (the second synaptic relay).
The highly specific projection of abducens internuclear neurons onto medial rectus motoneurons in the oculomotor nucleus is a good model to evaluate the dependence on target cells for survival during development and in the adult.
As has also been shown for Slack, Slick is expressed in the olfactory bulb, red nucleus, facial nucleus, pontine nucleus, oculomotor nucleus, substantia nigra, deep cerebellar nuclei, vestibular nucleus, and the thalamus.
Motoneurons in the primate oculomotor nucleus can be divided into two categories, those supplying twitch muscle fibers and those supplying nontwitch muscle fibers. Recent studies have shown that twitch motoneurons lie within the classical oculomotor nucleus (nIII), and nontwitch motoneurons lie around the borders.
It was clearly detected in the prefrontal cortex (middle laminae), hippocampal formation (except CA1), cerebellum, oculomotor nucleus, superior colliculus, red nucleus and substantia nigra pars compacta.
Pathological lesions included the spinal cord (spinocerebellar tracts, anterolateral fascicles, and posterior column), cerebellar dentate nucleus, pontine nucleus, pallidum, motor neurons including the oculomotor nucleus, and substantia nigra.
The three receptors were present in all neuronal populations investigated, including abducens motoneurons and internuclear neurons, medial rectus motoneurons of the oculomotor nucleus, and trochlear motoneurons.
Galectin-1 mRNA was predominantly observed in the cell bodies of neurons such as oculomotor nucleus (III), trochlear nucleus (IV), trigeminal motor nucleus (V), abducens nucleus (VI), facial nucleus (VII), hypoglossal nucleus (XII), red nucleus, and locus ceruleus.
The majority of vestibulospinal neurons (24/28) with axons descending through the contralateral MVST were also antidromically activated from the oculomotor nucleus, whereas almost all vestibulospinal neurons (19/20) with axons descending through the i-MVST were not.
The findings suggest that sustained performance during a difficult task is modulated by cortical inhibition of the parasympathetic pathway at the oculomotor nucleus.
We measured the effect of dark rearing on eye movements, gene expression in the oculomotor nucleus, and contractility of isolated extraocular muscles. Using microarrays and quantitative PCR, we found that dark rearing shifted the oculomotor nucleus transcriptome to a state of delayed/arrested development.
It summarizes some of the principal features that characterize the development of this circuit, including the gradual clustering of motoneurons in the oculomotor nucleus into functionally identifiable motoneuron pools, the patterning of vestibular projection neurons into coherent clusters with specific axonal trajectories and terminations onto the oculomotor motoneuron pools, the reverse order of synapse formation during development (motoneuron to muscle, then vestibular projection neuron to motoneuron), and the selectivity of initial synaptic termination at both the ultimate and penultimate relays within the reflex arc.
Magnetic resonance imaging showed a tiny infarct at the area of the oculomotor nucleus on the contralateral side.
We present a patient having 'top of the basilar syndrome' with midbrain infarction selectively involving the bilateral oculomotor nucleus. On the basis of clinical findings alone, we could not establish whether the precise location of the lesion was all the subdivisions of the oculomotor nucleus except the Edinger-Westphal nucleus or the central caudal nucleus and bilateral fascicles. However, because axial MRI showed a small midbrain infarct in the oculomotor nucleus region, we concluded that she had an isolated, pupil-sparing, bilateral oculomotor nuclear palsy caused by midbrain infarct..
Following the injection in the anteromedial tectum, most of the boutons and labeled neurons were found in the reticular formation rostral to the oculomotor nucleus.
Neurons were identified by antidromic responses to oculomotor nucleus stimulation and orthodromic responses to labyrinth stimulation, and were classified as having primarily anterior, posterior, or horizontal canal input based on response directionality.
Quite the opposite, insect predation was associated with increased Fos expression predominantly in the rostral two thirds of the lateral PAG, where the majority of the Fos-immunoreactive cells were found at the oculomotor nucleus levels.
At 3-3.5 d, transneuronal transfer involved premotor interneurons of trigeminal, auditory, and vestibular reflex pathways (in medullary and pontine reticular formation, trigeminal nuclei, periolivary and ventral cochlear nuclei, and medial vestibular nuclei), motor pathways (dorsolateral quadrant of contralateral red nucleus and pararubral area), deep cerebellar nuclei (lateral portion of interpositus nucleus and dorsolateral hump ipsilaterally), limbic relays (parabrachial and Kölliker-Fuse nuclei), and oculomotor structures involved in eye-eyelid coordination (oculomotor nucleus, supraoculomotor area, and interstitial nucleus of Cajal).
Almost half of the cells are distributed rostral to the oculomotor nucleus, both in and lateral to the anteromedian nucleus. Of the remaining preganglionic motoneurons, roughly 20% of the total are located dorsal to the oculomotor nucleus. An additional population, roughly 30% of the total, is located ventral to the oculomotor nucleus. In contrast, lens-related preganglionic motoneurons, that is, those controlling the ciliary muscle are particularly prevalent caudally, both dorsal and ventral to the oculomotor nucleus.
These gaze-related lid movements are produced by the levator palpebrae superioris muscle, whose motoneurons are located in the caudal central subdivision (CCS) of the oculomotor nucleus. This subset of riMLF neurons was not labeled when injections were localized within the oculomotor nucleus proper, without involving the CCS.
These neurons project onto the contralateral medial rectus motoneurons of the oculomotor nucleus.
Magnetic resonance imaging of the brain (MRI) revealed bilateral symmetrical lesions of high signal intensity in the posterior region of the putamen, the subthalamic nuclei, the dorsal medulla oblongata corresponding to inferior cerebellar peduncles and vestibular nuclei, the inferior colliculi and the periaqueductal gray matter surrounding the oculomotor nucleus of the midbrain.
Lewy bodies were also seen in the subcortical structures such as the dorsal motor nucleus, oculomotor nucleus, Meynert nucleus, putamen, and thalamus.
In order to assess the degree to which this transformation is evident in vestibular nucleus neurons of alert cats, we recorded the extracellular discharge properties of 138 second-order vestibular neurons in the superior and medial vestibular nucleus, including 64 neurons identified as second-order vestibulo-ocular neurons by antidromic responses to oculomotor nucleus stimulation and short-latency orthodromic responses to labyrinth stimulation (1.3 ms or less).
Central injections labeled large motoneurons within the abducens, trochlear or oculomotor nucleus, and smaller motoneurons lying mainly around the periphery of the motor nuclei. The peripheral neurons labeled from the lateral rectus muscle surround the medial half of the abducens nucleus: from superior oblique, they form a cap over the dorsal trochlear nucleus; from inferior oblique and superior rectus, they are scattered bilaterally around the midline, between the oculomotor nucleus; from both medial and inferior rectus, they lie mainly in the C-group, on the dorsomedial border of oculomotor nucleus.
An asymmetric activation of the oculomotor nucleus would generate an asymmetrical rotation of the eyes.
Initial neuro-ophthalmologic findings suggested involvement of the caudal part of the oculomotor nucleus and the left oculomotor nerve within the midbrain. The pattern of neuro-ophthalmologic impairment seen in our patient led us to conclude that the caudal oculomotor nucleus and medial part of the fascicular fibers of the left oculomotor nerve probably recovered first, after which recovery of the fascicular fibers progressed laterally.
To address the question of whether there is differential expression of the GluR2 subunit in motoneurons, we compared in normal adult rats expression of GluR2 mRNA and protein within two cranial motor nuclei that are either resistant (III; oculomotor nucleus) or vulnerable (XII; hypoglossal nucleus) to degeneration in ALS.
While neurons in the adult rat brain were generally positive, very prominent nogo-A mRNA and nogo-ABC mRNA signals were obtained from neurons of the hippocampus, piriform cortex, the red nucleus, and the oculomotor nucleus.
In the midbrain, GAL-ir neurons appeared in the pretectal olivary nucleus, oculomotor nucleus, the medial and lateral lemniscus, periaqueductal gray, and the interpeduncular nucleus.
We presented a patient of isolated inferior rectus muscle palsy from midbrain lacunar infarction involving the oculomotor nucleus. This lesion involved the right oculomotor nucleus, especially the dorso-lateral subnucleus extend to the inferior rectus muscle.
We thought that upward gaze palsy of the right eye was resulted from the infarction of the left riMLF or disruption of the axonal collateral of upward gaze fibers in the left oculomotor nucleus.
We also examined medial rectus muscle motoneuron compartmentalization in the squirrel monkey oculomotor nucleus and compared those cells to abducens nucleus motoneurons.
658, 182-204) had predicted that ongoing cognitive activation should result in inhibition of the light reaction at the level of the oculomotor nucleus, n. The locus of interference with the light reaction was the Edinger-Westphal complex of the oculomotor nucleus, which is the motor center for the pupillary sphincter muscles.
The axons of these neurons course through the contralateral medial longitudinal fascicle and contact the medial rectus motoneurons of the oculomotor nucleus.
The highly specific projection of abducens internuclear neurons on the medial rectus motoneurons of the oculomotor nucleus constitutes an optimal model for investigating the effects of axotomy in the central nervous system.
CR-ir motoneurons were also observed in the spinal cord and in the oculomotor nucleus.
Vestibular neurons containing constitutive NADPH-d/NOS were found to project predominantly to the oculomotor nucleus.
Although the substrate for vergence has been defined in the monkey as lying dorsal and lateral to the oculomotor nucleus, the human homologue is unknown.Method:- The authors reviewed the clinical features, ocular findings, and CT or MR lesions in seven patients with pseudoabducens palsy and "top-of-the-basilar" infarction. RESULTS: The smallest MR infarct produced an ipsilateral pseudoabducens palsy and CRN, and was located just rostral to the oculomotor nucleus, near the midbrain-diencephalic junction.
They can result from lesions located anywhere from the oculomotor nucleus to the termination of the third nerve in the extra-ocular muscles within the orbit.
A detailed, three-dimensional, schematic computer model of the oculomotor nucleus and fascicles was constructed.
Saccadic innervation from riMLF is unilateral to depressor muscles but bilateral to elevator muscles, with axons crossing within the oculomotor nucleus.
The ventral-caudal region, which corresponds to the central MRF, the cMRF, or nucleus subcuneiformis, is the focus of this paper and is located lateral to the oculomotor nucleus and caudal to the posterior commissure (PC).
In addition, label was present over the SR- and IO-motoneuron subgroups in the oculomotor nucleus and frontalis muscle motoneurons in the facial nucleus.
However, OBECs migrated preferentially towards abducens somata, in the direction opposite to the oculomotor nucleus target.
Strongly immunoreactive neurons were present in the oculomotor nucleus and ruber nucleus in the midbrain, the facial nucleus in the pons, the dorsal vagal nucleus and hypoglossal nucleus in the medulla oblongata and in the anterior horn as well as intermediolateral zone of the spinal cord.
Synchrony between late components of eyelid movements and eye movements as well as similarity of oblique eye movement components in different types of blinking suggest the existence of a premotor neural structure acting as a generator that coordinates impulses to different subnuclei of the oculomotor nucleus as well as the facial nerve nucleus during blinking independent from the ocular saccadic and/or vergence system.
The medial rectus muscle was innervated by the dorsomedial part of the oculomotor nucleus. The contralateral pattern consisted of motoneurons innervating the superior rectus and the superior oblique that were located respectively in the caudal portion of the ventral oculomotor nucleus and in the trochlear nucleus.
In the oculomotor nucleus, neuronal loss was seen only once in five mice, associated with very severe disease.
Here, we report an intense expression of torsinA mRNA in the substantia nigra pars compacta dopamine neurons, the locus ceruleus, the cerebellar dentate nucleus, Purkinje cells, the basis pontis, numerous thalamic nuclei, the pedunculopontine nucleus, the oculomotor nucleus, the hippocampal formation, and the frontal cortex.
The oculomotor nucleus in embryos at these stages is located at the cephalic flexure of the neural tube.
As well as this hindbrain expression, we also describe expression of GATA-2 in the otic vesicle, oculomotor nucleus, third nerve and metanephros..
Substantial brevican immunoreactivity was detected in a number of nuclei and in the reticular formations throughout the midbrain and hindbrain, including, but not limited to, the deep cerebellar nuclei, the trapezoid body, the red nucleus, the oculomotor nucleus, the vestibular nucleus, the cochlear nucleus, the gigantocellular reticular nucleus, the motor trigeminal nucleus, and the lateral superior olive.
The abducens internuclear and ascending tract of Deiters (ATD) pathways are the principal excitatory inputs to medial rectus motoneurons in the oculomotor nucleus and are related to the control of conjugate horizontal eye movements.
the oculomotor nucleus, Onufurowicz's nucleus, Clarke's nucleus, reticular formation of the brain stem, and subthalamic nucleus.
The trochlear nucleus was located caudal to the oculomotor nucleus from which it was separated by a gap.
From 9.5 to 11.5 dpc, activation of the gene spreads to many sites of early neuronal differentiation, such as the olfactory bulbs, the pretectum, and the oculomotor nucleus in the midbrain, a thin stripe of cells lining the floor plate from the mesencephalon to the cervical spinal cord and a ventral column of cells spanning the neural tube from rostral hindbrain and including motor neuron as well as ventral interneuron precursors.
The oculomotor nucleus and the medial habenula are unusual to the extent that each has a moderately dense serotonin terminal plexus, although neither receives innervation from the median or dorsal raphe.
In PD patients, cytoplasmic 8OHG immunoreactivity was intense in neurons of the SN, and present to a lesser extent in neurons of the nucleus raphe dorsalis and oculomotor nucleus, and occasionally in glia.
In addition, in the brainstem, the oculomotor nucleus, trochlear nucleus, mecencephalic and motor nuclei of trigeminal nerve (N), abducens nucleus, facial nucleus, nucleus of the raphe pontis, dorsoral motor nucleus of vagal N, hypoglossal nucleus and ambiguus nucleus showed motopsin mRNA expression.
Abducens internuclear and ascending tract of Deiters (ATD) inputs to medial rectus motoneurons in the oculomotor nucleus are important for conjugate horizontal movements. In the present study, the organization of these separate populations of neurons and their synaptic connections with medial rectus motoneurons in the cat oculomotor nucleus have been examined by light and electron microscopy by using retrograde and anterograde axonal tracers.
The findings agree with recent experimental evidence that a neural substrate in eyelid control lies in the supraoculomotor area immediately dorsal to the oculomotor nucleus. This may be explained by partial damages of the descending fibers, some of which decussate through the posterior commissure before it reaches the oculomotor nucleus.
PURPOSE: To report a case of isolated inferior rectus palsy secondary to a metastasis to the oculomotor nucleus. One lesion in the right midbrain was adjacent to the cerebral aqueduct in the right oculomotor nucleus. CONCLUSION: Metastasis to the oculomotor nucleus is a rare cause of isolated inferior rectus palsy; however, this entity should be considered in the differential diagnosis of an isolated inferior rectus palsy because of the life-threatening consequences of a brainstem lesion..
In the oculomotor nucleus, boutons were present exclusively in the case of the anteromedial injection.
Horseradish peroxidase (HRP), fluorescein-, or Texas red-(TRDA) coupled dextran-amine applied into the oculomotor nucleus of larval lamprey (Petromyzon marinus) retrogradely labeled two populations of contralateral abducens interneurons, one lateral and the other periventricular.
Labeled cells were revealed in the contralateral oculomotor nucleus.
Virus can also spread to the CNS via retrograde transport through the oculomotor nucleus that innervates extraocular muscles of the eye.
Neurons containing hybridization signal for ChAT mRNA were observed in the nucleus of the diagonal band of Broca, the basal nucleus of Meynert, the caudate nucleus, the putamen, the pedunculopontine tegmental nucleus, the laterodorsal tegmental nucleus, the parabigeminal nucleus, the oculomotor nucleus and the trochlear nucleus.
The fibers of these tracts could be followed to their different targets in the brain, namely the preoptic region, the rostral habenulae, the medial subhabenular and retrohabenular (post- and subcommissural) region, the medial thalamus, the dorsal hypothalamus, the pretectal area, and medial and dorsolateral tegmental mesencephalic regions (interstitial nucleus of Cajal, oculomotor nucleus, mesencephalic reticular area, nucleus profundus mesencephali, and central gray).
A few small cells in the ND project bilaterally to the oculomotor nucleus.
It was conceivable that the PAG lesion might be contributory to fatigable blepharoptosis (pseudomyasthenia) and supranuclear upward gaze palsy in the present case, because the PAG controls levator palpebrae neurons of central caudal nucleus in oculomotor nucleus complex and receives afferents from the limbic system., reticular formation and posterior commissure..
those in the oculomotor nucleus, trochlear nucleus, motor trigeminal nucleus, facial nucleus and hypoglossal nucleus, are TBP-1 mRNA positive.
HSV-1 immunoreactivity, initially detected at 3 days, increased in area and intensity in the superior colliculus, oculomotor nucleus, and geniculate through 5 days.
In five alert chronically-prepared cats we studied the response to sinusoidal 3-D whole body rotation of well-isolated vestibular nucleus neurons which were tested for monosynaptic input from the vestibular labyrinth, direct projection to the oculomotor nucleus and, in some cases, inhibition from cerebellar flocculus stimulation.
Antidromic stimulation in C6 and the oculomotor nucleus identified the projection pattern of each neuron.
Antidromic activation of axon collaterals distinguished between neurons projecting only to neck segments from those with collaterals to C6 and/or oculomotor nucleus. Of these, 43% had ascending collaterals to the oculomotor nucleus (VOC neurons), and 57% did not (VC neurons). Most C6-projecting neurons could not be activated from oculomotor nucleus (V-C6 neurons) and projected primarily ipsilaterally.
Another monopolar electrode was placed in the oculomotor nucleus to determine whether saccular nerve-activated vestibulospinal neurons have branches ascending to the oculomotor nucleus. Four saccular nerve-activated vestibulospinal neurons were also antidromically activated from the oculomotor nucleus.
Oculomotor and abducens internuclear neurons were retrogradely labeled after horseradish peroxidase injection into either the abducens or the oculomotor nucleus, respectively. Other interneurons located within the boundaries of the oculomotor nucleus were mainly calbindin-immunoreactive. The majority of abducens internuclear neurons projecting to the oculomotor nucleus (80.7%) contained calretinin. Moreover, the distribution of calretinin-immunoreactive terminals in the oculomotor nucleus overlapped that of the medial rectus motoneurons and matched the anterogradely labeled terminal field of the abducens internuclear neurons.
Motor neurone groups which tend to be spared in MND, such as those present in the oculomotor nucleus, showed a lower expression of EAAT2, with fewer perisomatic profiles.
We report a simple and easily-applicable method to intraoperatively monitor the oculomotor nerve and oculomotor nucleus in the brainstem.
Medium to strong immunoreactivity was observed in the cell body and dendrites of neurons of the oculomotor nucleus, superior colliculus and substantia gelatinosa reticulata.
FGF-10 mRNA was strongly expressed in several restricted nuclei, especially in motor nuclei, including the oculomotor nucleus, dorsal motor nucleus of vagus, motor trigeminal nucleus, facial nucleus and hypoglossal nucleus.
In the midbrain, NAIP-LI was located primarily within neurons of the red nucleus, the substantia nigra pars compacta, the oculomotor nucleus, and the trochlear nucleus.
Cats were anesthetized, and following topical ephedrine, pupillary constrictions were elicited by electrical stimulation of the intracranial oculomotor nucleus.
The neuronal structure of the somatic oculomotor nucleus (SON) was studied on the basis of Nissl and Golgi preparations, obtained from mesencephalons of 4 European bisons.
Less vascularized is the central oculomotor nucleus, and scanty blood vessels are found within the autonomic nucleus of the oculomotor nerve.
Three regions were found to evoke the accommodation response: the posterolateral pretectum, including the nucleus of the optic tract and the posterior pretectal nucleus; the posteromedial pretectum, including the nucleus of the posterior commissure (NPC) and adjacent commissural fibers; and the MRF area dorsolateral to the oculomotor nucleus.
PURPOSE: To compare the MR characteristics of the oculomotor nucleus with its appearance on anatomic images.
We first investigated the distribution of OOcVII motoneurons in the facial nucleus and LPIII motoneurons in the oculomotor nucleus by retrograde tracing of wheat germ-agglutinated horseradish peroxidase (WGA-HRP) injected into the appropriate muscles. We found an area in Vp and the adjacent rostral parts of pars oralis of the spinal trigeminal nucleus that gave clear projections to OOcVII and AccVI motoneurons and adjacent to LPIII motoneurons in the contralateral oculomotor nucleus.
In both cases, the dorsomedial mesencephalic tegmental region lateral to the oculomotor nucleus, including the central tegmental tract and the ventral part of the periaqueductal gray, was involved commonly in the lesions.
Another monopolar electrode was also placed in the oculomotor nucleus to study whether utricular nerve-activated vestibulospinal neurons have ascending branches to the oculomotor nucleus. Almost none of the utricular nerve-activated vestibular neurons had ascending branches to the oculomotor nucleus..
Ptosis and downgaze paralysis, in a case of vascular insufficiency, were the result of a specific loss of levator palpebrae (LP) motoneurons in the oculomotor nucleus, and a partial cell loss in the rostral interstitial nucleus of the MLF (riMLF), respectively.
The tracers were injected either in the AON, the oculomotor nucleus or the rostralmost spinal cord. HRP injection in the AON labelled thick axons that coursed to the basal mesencephalic tegmentum, where most decussate and project to the oculomotor nucleus and the third Müller cell. HRP or FDA injections in the oculomotor nucleus labelled both large and small neurons of the AON, mostly contralateral to the injection site, as well as of cells in the intermediate octavomotor nucleus, mainly ipsilateral.
The deeper the sleep, the narrower the pupil: miosis during drowsiness, sleep, sedation and general anesthesia relies on reduced inhibition of the oculomotor nucleus and, even more, on reduced sympathetic tone (it is as sympatholysis that accounts for the miosis exerted by the famous "cocktail lytique" onto an iris whose sphincter is weakened from briskly elevated IOP in angle-closure glaucoma).
Although pathological changes are observed in both the oculomotor nucleus and abducens nucleus in autopsied cases of infantile progressive spinal muscular atrophy, external and internal ocular palsy and ptosis have not been previously reported clinically.
The midbrain lesion was located in the paramedian area and the bilateral ptosis, bilateral upward gaze palsy and adduction disturbance of the contralateral eye were considered to be caused by the lesion involving the unilateral oculomotor nucleus.
This rare "crossed vertical gaze paresis" results from a lesion near the oculomotor nucleus affecting ipsilateral downward gaze and contralateral upward gaze fibres, originating in the rostral interstitial nucleus of the medial longitudinal fasciculus (riMLF)..
Following the injection of biocytin, in the ascending projections, labeled terminals were seen mainly in the caudal portion of the nucleus of the optic tract, the nucleus of the posterior commissure, the posterior pretectal nucleus, the olivary pretectal nucleus, the mesencephalic reticular formation at the level of the oculomotor nucleus, and the lateral posterior nucleus of the thalamus on the ipsilateral side. These findings suggest that the accommodation area in the superior colliculus projects to the oculomotor nucleus through the ipsilateral pretectal area, especially the nucleus of the optic tract, the nucleus of posterior commissure, and the posterior pretectal nucleus, and also projects to the pupilloconstriction area (the olivary pretectal nucleus), the vergence-related area (the mesencephalic reticular formation), and the active visual fixation-related area (the nucleus raphe interpositus)..
In contrast to the substantia nigra, the oculomotor neurons in the same midbrain sections showed no or only weak staining for HNE-modified proteins in both PD and control subjects; young control subjects did not show any immunostaining; however, aged control subjects showed weak staining in the oculomotor nucleus, suggesting age-related accumulation of HNE-modified proteins in the neuron.
Active degenerating lesions were found in the substantia nigra (patients 3, 4 and 5) and the oculomotor nucleus (patient 5) which might explain the clinical observation of chronic active disease in these patients.
In addition, intense v7-3 mRNA expression was found in the motor nuclei including the oculomotor nucleus, abducens nucleus, trigeminal motor nucleus, facial nucleus, hypoglossal nucleus and ventral horn of spinal cord.
In this anatomical study of the pretectum, projections from NOT and ol to structures around the oculomotor nucleus were traced in the monkey, to determine which cell groups they innervated. 3[ H]-leucine injections were placed into NOT and ol, and labelled terminals were observed just outside the classical oculomotor nucleus (nIII), in the "C-group' and midline cell clusters, both of which contain small motoneurons of the extraocular eye muscles.
The posterior commissure system gave rise to dense terminal fields in the contralateral NIC, the oculomotor nucleus, and the trochlear nucleus.
Contradictory results have been reported about the inhibitory input to the medial rectus subdivision of the oculomotor nucleus of the cat. In the present ultrastructural study, we quantified the GABAergic and glycinergic terminals in the various subdivisions of the rabbit oculomotor nucleus with the use of post-embedding immunocytochemistry combined with retrograde tracing of horseradish peroxidase.
Some brainstem neurons, such as those in the oculomotor nucleus, substantia nigra and pontine nucleus, were also positive for the Factor.
The neural circuit consists of neurons in the paramedian pontine reticular formation (burst, tonic and pause cells), the vestibular nucleus, abducens nucleus, oculomotor nucleus, cerebellum, substantia nigra, nucleus reticularis tegmenti pontis, the thalamus, the deep layers of the superior colliculus and the oculomotor plant for each eye.
Magnetic resonance imaging (MRI) demonstrated an infarct in the tegmentum of the mesencephalon including the right red nucleus and the periaqueductal area, superior to the oculomotor nucleus, and contiguous through the left thalamus.
Increased AP produced extensive Fos-like immunoreactivity within the lateral PAG, beginning at the level of the oculomotor nucleus.
[ 3H]sumatriptan binding sites with a low affinity for 5-CT predominated in the intermediate neocortical layers, the claustrum (in the guinea-pig only), the mammillary nuclei, most of the thalamic nuclei and the principal oculomotor nucleus (in the guinea-pig only).
Also a contralateral projection to the oculomotor nucleus and an ipsilateral projection to the pontine nucleus and the nucleus of the optic tract were found.
These cell groups are located in the dorsal telencephalic area, the inferior lobes of the hypothalamus, the pretectal area, the magnocellular superficial pretectal nucleus, the optic tectum, the oculomotor nucleus, the trochlear nucleus, the magnocellular vestibular nucleus, the secondary gustatory nucleus, the superior and medial reticular nuclei, the motor nucleus of the vagus and the ventral horn of the spinal cord.
It is expressed in: (1) motor nuclei such as the oculomotor nucleus, trochlear nucleus, motor trigeminal nucleus, abducens nucleus, facial nucleus, ambiguus nucleus, dorsal motor nucleus of vagus and hypoglossal nucleus; (2) several sensory-related nuclei like the mesencephalic trigeminal nucleus, ventral nucleus of the lateral lemniscus, lateral and spinal vestibular nuclei, ventral and dorsal cochlear nuclei and nucleus of the trapezoid body; and (3) other regions such as the red nucleus, dorsal raphe nucleus, pontine nuclei, three cerebellar nuclei (medial, interposed and lateral), Purkinje cells, cells in the granular layer of the cerebellum, locus coeruleus, several areas of the reticular nucleus and area postrema..
The KV3.1b protein is also present in various neuronal populations involved in the processing of auditory signals, including the inferior colliculus, the nuclei of the lateral lemniscus, the superior olive, and some parts of the cochlear nuclei; as well as in several other neuronal groups in the brainstem (e.g., in the oculomotor nucleus, the pontine nuclei, the reticulotegmental nucleus of the pons, trigeminal and vestibular nuclei, and the reticular formation) and subsets of neurons in the neocortex, the hippocampus and the caudate-putamen shown by double staining to correspond to neurons containing parvalbumin.
However, FGF-9 mRNA was also strongly expressed in several specific nuclei including the red nucleus and oculomotor nucleus in the midbrain, the vestibular nucleus and facial nucleus in the brainstem and the medial cerebellar nucleus, interposed cerebellar nucleus and lateral cerebellar nucleus in the cerebellum.
Both medium-lead BNs (MLBNs) and BTNs projected to the inferior rectus (IR) subdivision of the oculomotor nucleus on both sides. MLBNs projected to the trochlear nucleus as well through collateral branches of the axon projecting to the oculomotor nucleus.
Morphological development of the rat oculomotor nucleus was investigated on postnatal day 15 following a prenatal ethanol exposure. There was an alcohol-induced reduction in the overall size of the cross-sectional region of the oculomotor nucleus, but no effect on the number of neurons per unit area of that total oculomotor region, indicating a delay or alteration of the migration of neurons to their normal clustered position in the center of the nucleus. The results of this study demonstrate that gestational alcohol exposure can retard the maturation of the oculomotor nucleus..
In the present study, we demonstrate with the use of retrograde double labeling techniques in rabbits and rats, that the neurons in these pre-oculomotor nuclei that project to the inferior olive are intermingled with those that project to the oculomotor nucleus, but that virtually none project to both..
Studies of the pathways involved in the vestibulo-ocular reflex have suggested that the projection from the superior vestibular nucleus to the ipsilateral oculomotor nucleus is inhibitory, whereas the medial vestibular nucleus, the abducens nucleus and the contralateral superior vestibular nucleus most likely exert excitatory effects on oculomotor neurons. In order to determine directly the termination pattern and the neurotransmitter of these afferents, we studied their input to the oculomotor nucleus in the rabbit at the light microscopic level with the use of anterograde tracing of Phaseolus vulgaris-leucoagglutinin combined with retrograde tracing of horseradish peroxidase from the extraocular muscles, and at the ultrastructural level with the use of anterograde tracing of wheatgerm-agglutinated horseradish peroxidase combined with GABA and glycine postembedding immunocytochemistry. The present study provides the first direct anatomical evidence that most, if not all, of the synaptic input from the superior vestibular nucleus to the ipsilateral oculomotor nucleus is GABAergic, and that the medial rectus subdivision is included in the termination area.
We have previously reported that axon collaterals of posterior canal-activated excitatory vestibular (PC) neurons project to the contralateral oculomotor nucleus, and rostrally to the thalamus.
In contrast, after HRP injection into the right LPS of the rabbit, HRP-labeled neurons were found only in the contralateral oculomotor nucleus. In the double-labeling study, after injection of fast blue (FB) into the right LPS and diamidino yellow dihydrochloride (DY) into the left LPS of the cat and the rabbit, no double-labeled neurons were noted in the central caudal nucleus of the cat nor in the oculomotor nucleus of the rabbit, although double-labeled neurons were identified in the central caudal nucleus of the monkey in our previous study.
Regardless of which nerve branch was labeled, the full range of motoneuron soma sizes was found, and these were distributed throughout the IO subdivision of the oculomotor nucleus. But no topographic organization of motoneurons was found within the IO division of the oculomotor nucleus..
The brain appeared macroscopically normal but histology revealed many neurofibrillary tangles, particularly in medial temporal lobe structures, insula, nucleus basalis, hippocampus, oculomotor nucleus, raphe nuclei and locus ceruleus.
Retrograde tracing with horseradish peroxidase and biotinylated dextran amines resulted in labeling on the contralateral N IV of motoneurons with diverse morphologies and in direct caudal continuation with the oculomotor nucleus. Their dendritic arborizations extend profusely in the ipsilateral tegmentum and reach the oculomotor nucleus, the fasciculus longitudinalis medialis and also small processes branch towards the ventricle.
In the mesencephalon, there was particularly strong labeling in the pars compacta and reticulata of the substantia nigra, central gray, and red nucleus, in the Darkschewitsch nucleus, and in the medial accessory oculomotor nucleus.
High levels of [ 3H]-Tf binding were found in the dorsal raphé, oculomotor nucleus and periaqueductal grey whilst lower levels of [ 3H]-Tf binding were found in the tegmentum, red nucleus and substantia nigra. Significant reductions in binding were found in the substantia nigra, red nucleus and oculomotor nucleus in PD, the reductions in [ 3H]-Tf binding being similar to the loss of nigral neurons in PD.
Central chromatolysis of a few neurons in the oculomotor nucleus was seen.
Brain magnetic resonance imaging demonstrated a high-intensity area in the left oculomotor nucleus and its fascicles in the midbrain on T1- and T2-weighted image. Oculomotor nerve palsy of this type was consistent with the syndrome of oculomotor nucleus described by Pierrot-Deseillingny in 1981.
T2 weighted magnetic resonance imaging (MRI) revealed high intensity area in the medial part of the right midbrain tegmentum where the oculomotor nucleus located, and diffusion weighted MRI demonstrated high intensity area which corresponded to the oculomotor fascicles of the midbrain. The diagnosis of small infarction of the right oculomotor nucleus presenting ipsilateral external ophthalmoplegia was made. The superior rectus muscle is innervated by the neurons in the contralateral oculomotor nucleus, and the other external ocular muscles innervated by the third cranial nerve are conducted by the neurons in the ipsilateral oculomotor nucleus; therefore, unilateral oculomotor nuclear lesion generally causes ipsilateral ophthalmoplegia plus contralateral superior rectus palsy.
The intense oxidase reactions were present in the red nucleus, oculomotor nucleus, trochlear nucleus, ventral nucleus of the lateral lemniscus, dorsal and ventral cochlear nuclei, vestibular nuclei, nuclei of posterior funiculus, nucleus of the spinal tract of the trigeminal nerve, lateral reticular nucleus, inferior olivary nucleus, and hypoglossal nucleus.
Recent investigations revealed the localized distribution of the motoneuron subgroups within the mammalian oculomotor nucleus. Our results demonstrated that: 1) the average total number of the neurons in the motor neuron pool of SR was 322.7 +/- 40.1; 2) topographically, about 94.65% of the motoneurons controlling SR were located in the contralateral side, while the remaining 5.35% lay ipsilaterally; 3) all the IO motoneurons were present on the same side of the muscle they innervate; 4) the motoneurons of SR and IO did not form separate subnuclei, but were intermingling with each other; 5) functionally, about 94.59%, 4.26% and 1.15% of the total motoneurons in the SR subnucleus of either oculomotor nucleus were projecting contralaterally, ipsilaterally and bilaterally, respectively; 6) although the distribution of the perikarya was not homogeneous, the bilaterally projecting (i.e., to both SR) cells were disposed centrally, and their double labeling indicated that their axons innervate the bilateral SR via axonal bifurcation and/or collateral branching; and 7) the motoneurons of SR and IO were functionally segregated from each other as no bilaterally projecting neurons (i.e., to SR and IO) were found..
Pathologic examination of the central nervous system in both patients revealed degeneration and loss of spinal and cranial nerve motor nuclei, including the oculomotor nucleus.
Such region-specific expressions were also discerned in the central gray, the superior and inferior colliculi, the medial accessory oculomotor nucleus, the locus ceruleus, the parabrachial nucleus, nucleus of the solitary tract, the caudal subnucleus of the trigeminal spinal tract nucleus, and the inferior olive.
Brainstem motor nuclei which tend to be affected in motor neuron disease (MND) had very low densities of binding sites, whereas the oculomotor nucleus had a higher density.
Histochemistry revealed labeling associated with the plasma membrane in highly discrete nerve cell bodies of the frontoparietal cortex, the red nucleus, the zona reticulata of the substantia nigra, the oculomotor nucleus and the reticular thalamic nucleus.
Oculomotor internuclear neurons (OINs) in monkeys project primarily from the medial rectus subdivisions of the oculomotor nucleus to the contralateral abducens nucleus, although there is a smaller ipsilateral projection as well. Identified OINs were compared with a large sample of non-activated and untested horizontal burst-tonic cells in the medial rectus subdivisions of the oculomotor nucleus. Microstimulation of the oculomotor nucleus where both the OINs and medial rectus motoneurons were located resulted in a large adducting twitch of the ipsilateral eye and a smaller abducting twitch of the contralateral eye. Injection of 10% lidocaine HCl into the medial rectus subdivision of the oculomotor nucleus caused a reversible inactivation of the medial rectus motoneurons and OINs.
It is postulated that the supranuclear lateral gaze palsy was caused by impairment of supranuclear control by involvement of lateral gaze pathways to gaze center coursing near the oculomotor nucleus..
In elasmobranch fishes, including the Atlantic stingray, the medial rectus muscle is innervated by the contralateral oculomotor nucleus. This is different from most vertebrates, in which the medial rectus is innervated by the ipsilateral oculomotor nucleus. This hypothesis was examined in the Atlantic stingray by injecting horseradish peroxidase unilaterally into the oculomotor nucleus.
Neural projections from the frontal cerebral cortex to the oculomotor nucleus (3N) were investigated in 1- to 2-year-old cats by retrograde and anterograde axonal and transneuronal transport of wheat germ agglutinin-conjugated horseradish peroxidase (WGA-HRP).
We have now determined the morphology of individual excitatory second-order neurons of the anterior semicircular canal system that course outside the MLF to the oculomotor nucleus. The main axon continued its trajectory to the caudal edge of the red nucleus from where it coursed back toward the oculomotor nucleus. Within the oculomotor nucleus, collaterals reached superior rectus and inferior oblique motoneurons. Some axon branches recrossed the midline within the oculomotor nucleus and reached the superior rectus motoneuron subdivision on that side.
The neurons of the oculomotor nucleus were immunopositive in all the brains.
The brains and spinal cords from 11 patients with sALS and 20 normal controls (NCs) were used, and the following four nuclei (three motor nuclei and one autonomic nucleus) were examined: the oculomotor nucleus; the hypoglossal nucleus; the cervical motor nucleus; and Onuf's nucleus. The average total number of neurons after KB staining was similar in sALS patients and NCs in both the oculomotor nucleus and Onuf's nucleus, but the number in the hypoglossal and cervical motor nuclei was significantly lower in sALS. The ratio of MnSOD-positive neurons to total neurons visible after KB staining, calculated as an index of the expression of MnSOD, was significantly higher in the oculomotor nucleus and Onuf's nucleus, and lower in the hypoglossal nucleus in sALS patients than in NCs.
Microscopic examination showed a four-layered polymicrogyria involving the first temporal gyrus and in the brainstem a selective destruction of the left oculomotor nucleus. The brain stem lesion, destroying unilaterally the third cranial nerve nucleus gives a good example of the complex somatotopia of this oculomotor nucleus..
The fate of abducens internuclear neurons was studied after the loss of their target medical rectus motoneurons of the oculomotor nucleus in adult cats. In contrast, the density of axonal terminals of abducens internuclear neurons in the oculomotor nucleus progressively decreased during the year following target loss. Evidence is presented for the reinnervation of a new neuronal target within the oculomotor nucleus that might support both the long-term survival and the recovery of physiological characteristics in the abducens internuclear neurons..
These latter nuclei, the periventricular area, the posterior commissure, the nucleus lentiformis mesencephali, the oculomotor nucleus, and the raphe nuclei contained a dense plexus of substance P immunoreactive fibers.
Abducens internuclear neurons were chosen as the experimental model because of their highly specific projection onto the medial rectus motoneurons of the oculomotor nucleus.
The neuronal target--the medial rectus motoneurons of the oculomotor nucleus--was selectively destroyed by the injection of toxic ricin into the medial rectus muscle. Ultrastructural examination of the oculomotor nucleus 10 days after the lesion revealed numerous empty spaces left by the dead motoneurons. At longer intervals (> one month), the ultrastructure of the oculomotor nucleus was re-established and labeled boutons were observed contacting either unidentified dendrites within the neuropil or the soma and proximal dendrites of the oculomotor internuclear neurons, that project to the abducens nucleus.
In the present study we examined the possible colocalization of the inhibitory neurotransmitters glycine and GABA in the oculomotor nucleus of the rabbit.
Chick ciliary ganglion neurons receive innervation from a single source, the accessory oculomotor nucleus (AON), and nicotinic ACh receptors (AChRs) mediate chemical synaptic transmission through the ganglion.
However, the dentate nucleus, spinocerebellar tracts, and oculomotor nucleus including the medial longitudinal fasciculus were spared.
Medical rectus motoneurons were distributed in three subgroups in the ipsilateral oculomotor nucleus, a pattern similar to that of the monkey. Specifically, the majority of levator palpebrae motoneurons were located contralaterally, in the caudal central subdivision of the oculomotor nucleus, and the superior rectus motoneurons had a dorsocaudal location in the contralateral oculomotor nucleus.
The lesion involved oculomotor nucleus on a side.
An extensive superposition among the motor pools of the oculomotor nucleus (ON) has been observed.
The mean eye position sensitivity of these position-vestibular cells was significantly lower than that of cells projecting to the oculomotor nucleus (OMN). No cells could be antidromically activated from both the oculomotor nucleus and the flocculus..
Since muscles innervated by the oculomotor nucleus (OCM) also appear to be involved in this reflex, retrograde and anterograde tracers were used in this study to determine whether there are projections from the TSC and LPT to the OCM in the rabbit.
Enzyme injections were made into the ipsilateral lateral rectus and retractor bulbi muscles and into the contralateral oculomotor nucleus.
The characterization of GABA-immunoreactive terminals in the oculomotor nucleus was carried out at the light and electron microscopic levels. GABA-immunopositive puncta suggestive of boutons were abundant in semithin sections throughout the oculomotor nucleus, and were found in close apposition to somata and dendrites. Semithin sections of the oculomotor nucleus containing retrogradely labeled medial rectus motoneurons and immunostained for GABA revealed numerous immunoreactive puncta in close apposition to horseradish peroxidase-labeled somata and in the surrounding neuropil. Their features and density were similar to those found in the remaining motoneuronal subgroups of the oculomotor nucleus.
The goal of this work was to compare the distribution and morphology of neurons projecting to the oculomotor nucleus in goldfish with those previously described in other vertebrate groups. The tracer was electrophoretically injected into the oculomotor nucleus. The location of the injection site was determined by the antidromic field potential elicited in the oculomotor nucleus by electrical stimulation of the oculomotor nerve. In order of quantitative importance, the afferent areas to the oculomotor nucleus were: (1) the ipsilateral anterior nucleus and the contralateral tangential and descending nuclei of the octaval column. The similarity in the structures projecting to the oculomotor nucleus in goldfish to those in other vertebrates suggests that the neural network involved in the oculomotor system is quite conservative throughout phylogeny. Nevertheless, in goldfish these projections appeared with some specific peculiarities, such as the cerebellar and mesencephalic afferents to the oculomotor nucleus..
The pear-shaped neurons of the optic tectum, and perikarya of the oculomotor nucleus in the midbrain were also immunoreactive.
The CT brain scan revealed a paramedian mesencephalic lesion contiguous with the oculomotor nucleus, sparing the midbrain tectum and the posterior commissure..
Motoneuron recruitment was tested by electrical stimulation of the medial rectus subdivision of the contralateral oculomotor nucleus.
Abducens interneurons project to the medial rectus subdivision of the contralateral oculomotor nucleus and have a role in the mediation of horizontal conjugate gaze.
Alternatively, a ventral tegmental tract could transmit upward smooth pursuit signals between the y-group nucleus and the oculomotor nucleus.
This particularly presentation is due to the innervation of the superior rectus which comes mainly from the contralateral oculomotor nucleus.
All of the neuronal populations examined are known to undergo naturally occurring cell death, and they include spinal and cranial motoneurons, dorsal root ganglia, sympathetic ganglia, nodose ganglia, ciliary ganglia, and sympathetic preganglionic neurons in the PNS, as well as the accessory oculomotor nucleus, the isthmo-optic nucleus, and the brainstem auditory nuclei laminaris and magnocellularis in the CNS.
In the tegmentum, dorsolateral part around the left oculomotor nucleus was involved. Therefore, we considered that the human divergence center of the eyes might exist in the lateral tegmentum of the midbrain, just lateral and dorsal to the oculomotor nucleus..
The activity of 57 near-response neurons located dorsally and dorsolaterally to the oculomotor nucleus was recorded before and after adaptation while the monkeys monocularly viewed targets at a range of distances.
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