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The Journal of Comparative Neurology Oct 1987The peripheral and central aspects of the extraocular system were studied in the weakly electric fish Gnathonemus petersii. All six extraocular muscles show a similar...
The peripheral and central aspects of the extraocular system were studied in the weakly electric fish Gnathonemus petersii. All six extraocular muscles show a similar composition of large and small fibers grouped characteristically in the proximal and distal regions respectively. The exit of the three extraocular nerves from the brain is similar to that in other vertebrates. However, the intracephalic and intracranial course of the trochlear nerve is unusual, partly because of the extraordinary hypertrophy of the cerebellum. The three nerves course rostrally on the ventral brain surface; the trochlear nerve penetrates the orbital cavity separately from the two other nerves. The fiber-diameter spectrum of each extraocular nerve is bimodal; unmyelinated fibers were not observed in any of the nerves. The location of the extraocular motor nuclei was established by retrograde axonal transport of HRP or cobaltic-lysine complex. The oculomotor nucleus is situated ventral to the posterior pole of the magnocellular mesencephalic nucleus and the trochlear nucleus is found caudal and dorsal to this. The abducens nucleus is situated at the level of the octavolateral efferent nucleus and consists of a single group of cells on each side of the ventral tegmentum. The oculomotor nucleus of G. petersii shows a somatotopic organization. The superior rectus muscle receives a contralateral innervation whereas the inferior rectus and oblique muscles and the internal rectus muscles receive an ipsilateral innervation. The superior oblique muscle is innervated by contralateral trochlear motoneurons and the external rectus by ipsilateral abducens motoneurons. The majority of extraocular motoneurons have piriform perikarya and long beaded dendrites that extend laterally in the oculomotor and abducens nuclei and rostrally in the trochlear nucleus. The terminal dendritic portions of trochlear motoneurons widely overlap with oculomotor dendrites and perikarya. In all three nuclei the axon originates opposite to the main dendrite. Collaterals of the hairpin-bend abducens axons could be identified in a few cases. The oculomotor system of G. petersii appears basically similar to that of other teleosts; the differences observed concern mainly the structure of the abducens nucleus, the intracranial and intracephalic course of the trochlear nerve, and the relatively small number of axons in each nerve.
Topics: Abducens Nerve; Animals; Electric Fish; Oculomotor Muscles; Oculomotor Nerve; Trochlear Nerve
PubMed: 3680639
DOI: 10.1002/cne.902640404 -
Seminars in Neurology Feb 2009In this article, isolated palsies of cranial nerves III, IV, and VI are addressed. After discussion of the pertinent clinical anatomy of cranial nerves III, IV, and VI,... (Review)
Review
In this article, isolated palsies of cranial nerves III, IV, and VI are addressed. After discussion of the pertinent clinical anatomy of cranial nerves III, IV, and VI, the isolated involvement of each of these oculomotor nerves is defined. Based on a review of the literature, methods of evaluation and follow-up of patients presenting with diplopia from lesions of these cranial nerves are presented.
Topics: Abducens Nerve; Abducens Nerve Diseases; Humans; Oculomotor Nerve; Oculomotor Nerve Diseases; Paralysis; Trochlear Nerve; Trochlear Nerve Diseases
PubMed: 19214929
DOI: 10.1055/s-0028-1124019 -
Singapore Medical Journal Sep 2000We describe three patients with aberrant regeneration of the third nerve secondary to traumatic brain injury. The full blown features of the syndrome include horizontal...
We describe three patients with aberrant regeneration of the third nerve secondary to traumatic brain injury. The full blown features of the syndrome include horizontal gaze-eyelid synkinesis, pseudo-Graefe sign, limitation of elevation and depression of the eye with retraction of the globe on attempted vertical movements, adduction of the involved eye on attempted elevation or depression, pseudo-Argyll Robertson pupil and absent vertical optokinetic response. The 'misdirection' incidence in our study is 15%.
Topics: Adult; Brain Injuries; Female; Humans; Male; Middle Aged; Ocular Motility Disorders; Oculomotor Nerve; Oculomotor Nerve Diseases; Pregnancy; Pupil Disorders
PubMed: 11193120
DOI: No ID Found -
Brain Research Jan 1982Slices of the cat third oculomotor nucleus were incubated in vitro with [3H]glutamic acid. Electron microscopic radioautographs revealed that glutamate had been taken by...
Slices of the cat third oculomotor nucleus were incubated in vitro with [3H]glutamic acid. Electron microscopic radioautographs revealed that glutamate had been taken by small nerve endings distributed on the oculomotor motoneuron distal dendrites. In contrast, there was no uptake in the other types of terminals. The labeled terminals seem to correspond to the excitatory vestibulo-oculomotor nerve endings and different correlations suggest their glutamergic nature.
Topics: Animals; Autoradiography; Cats; Dendrites; Glutamates; Glutamic Acid; Microscopy, Electron; Neurons; Oculomotor Nerve; Proline; Tritium
PubMed: 6120026
DOI: 10.1016/0006-8993(82)90379-1 -
Progress in Brain Research 1972
Topics: Animals; Eye Movements; Oculomotor Nerve; Reticular Formation; Vestibular Function Tests; Vestibular Nuclei
PubMed: 4642053
DOI: No ID Found -
Experimental Eye Research May 1990Electrical or chemical activation of the oculomotor nucleus (ONC) was performed in pentobarbital anesthetized cats to determine the role of parasympathetic nervous input...
Electrical or chemical activation of the oculomotor nucleus (ONC) was performed in pentobarbital anesthetized cats to determine the role of parasympathetic nervous input to the eye in modulating intraocular pressure (IOP). In all animals, the vagosympathetic nerve trunks were sectioned bilaterally at the mid-cervical level. Intracranial stimulation of the ONC produced miosis and a bilateral sustained rise in IOP with little or no cardiovascular response. During stimulation, IOP increased by approximately 35-40%, with an additional small rise seen when the current was turned off. The secondary rise in IOP probably represents the actual pressure level reached which was otherwise masked by intense accommodation due to stimulation. The rise in IOP was not antagonized with gallamine triethiodide. However, both IOP and pupillary responses were blocked by either hexamethonium (1.5 mg kg-1, i.v.) or atropine (0.5 mg kg-1, i.v.). These results provide evidence for a neural parasympathetic mechanism for increasing IOP in cats. In another group, activation of ONC following electrolytic lesion of the preganglionic parasympathetic nerve to one eye, produced a rise in IOP and miosis only on the side with intact oculomotor nerve indicating that the rise in IOP is in part mediated by nerve fibers that travel to the eye along the oculomotor nerve trunk. Microinjection of L-glutamate (2.5 x 10(-7) M) into the ONC produced a bilateral rise in IOP that lasted for more than 15 min. This increase in IOP was greater than 50% of control levels and was accompanied with miosis.(ABSTRACT TRUNCATED AT 250 WORDS)
Topics: Animals; Atropine; Cats; Electric Stimulation; Ganglionic Blockers; Glutamates; Glutamic Acid; Hexamethonium; Hexamethonium Compounds; Intraocular Pressure; Neural Pathways; Neurons, Efferent; Oculomotor Nerve; Parasympathetic Nervous System
PubMed: 1973653
DOI: 10.1016/0014-4835(90)90032-p -
Journal of Neuroradiology = Journal de... Feb 2020
Topics: Adult; Female; Humans; Magnetic Resonance Imaging; Multiple Sclerosis, Relapsing-Remitting; Oculomotor Nerve; Optic Chiasm
PubMed: 30423382
DOI: 10.1016/j.neurad.2018.10.007 -
Neuroscience Letters Jan 1991A brain slice preparation was developed to permit recordings to be made from neurones in the anterior lateral pedal lobe of the octopus CNS. These are the first...
A brain slice preparation was developed to permit recordings to be made from neurones in the anterior lateral pedal lobe of the octopus CNS. These are the first intracellular recordings obtained from identified neurones in the cephalopod CNS. The neurones had membrane resting potentials of around -40 mV and action potentials up to 20 mV in amplitude. Spontaneous synaptic potentials could be seen in some cells. All of the oculomotor neurones, identified by stimulation of the anterior oculomotor nerve to evoke an antidromic potential, received an excitatory input from the visual system, shown by electrical stimulation of the optic tract, and some also received an excitatory input from the statocyst, as shown by electrical stimulation of the macula nerve.
Topics: Action Potentials; Animals; Brain; Electric Stimulation; Electrophysiology; Evoked Potentials; In Vitro Techniques; Neurons; Octopodiformes; Oculomotor Nerve; Synapses
PubMed: 2020378
DOI: 10.1016/0304-3940(91)90688-p -
Vision Research Nov 1971
Topics: Eye Movements; Fixation, Ocular; Humans; Oculomotor Nerve; Strabismus; Vision Tests; Visual Perception
PubMed: 5148579
DOI: 10.1016/0042-6989(71)90018-6 -
American Journal of Ophthalmology Feb 2007The etiology of third nerve palsy is usually diagnosed by history, motility examination, and presence of lid and pupil involvement, as well as cranial and vascular...
PURPOSE
The etiology of third nerve palsy is usually diagnosed by history, motility examination, and presence of lid and pupil involvement, as well as cranial and vascular imaging. We used high-resolution magnetic resonance imaging (hrMRI) of the oculomotor nerve and affected extraocular muscles (EOMs) to investigate oculomotor palsy.
DESIGN
Prospective, noncomparative, observational case series in an academic referral setting.
METHODS
Twelve patients with nonaneurysmal oculomotor palsy of 0.75 to 252 months' duration were studied. In the orbit and along the intracranial oculomotor nerve, hrMRI at 1- to 2-mm thickness was performed. Coronal plane images of each orbit were obtained in multiple, controlled gaze positions. Structural abnormalities of the oculomotor nerve and associated changes in EOM volume and contractility were evaluated.
RESULTS
Cases were categorized as tumor related, congenital, diabetic, traumatic, and idiopathic according to clinical characteristics and hrMRI findings. Reduction of volume and contractility of affected EOMs were noted in six patients; however, there was no marked EOMs atrophy in two cases of diabetic oculomotor palsy, and there were four cases of aberrant regeneration. hrMRI demonstrated the oculomotor nerve at the midbrain and at EOMs in all cases, and in two cases with previous normal neuroimaging elsewhere that demonstrated contrast-enhancing tumors on the oculomotor nerve. One patient with apparently unilateral congenital inferior division oculomotor palsy had no detectable ipsilateral and a hypoplastic contralateral oculomotor nerve exiting the midbrain.
CONCLUSIONS
hrMRI provides valuable information in patients with oculomotor palsy, such as structural abnormalities of the orbit and oculomotor nerve, and atrophy and diminished contractility of innervated EOMs. This information could be helpful in diagnosis and management of oculomotor palsy.
Topics: Adult; Aged; Aged, 80 and over; Atrophy; Child; Female; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Muscle Contraction; Oculomotor Muscles; Oculomotor Nerve; Oculomotor Nerve Diseases; Ophthalmoplegia; Prospective Studies
PubMed: 17173848
DOI: 10.1016/j.ajo.2006.10.035