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Frontiers in Neuroscience 2020Amyotrophic lateral sclerosis (ALS) is a progressive multifactorial disease characterized by the loss of motor neurons (MNs). Not all MNs undergo degeneration: neurons... (Review)
Review
Amyotrophic lateral sclerosis (ALS) is a progressive multifactorial disease characterized by the loss of motor neurons (MNs). Not all MNs undergo degeneration: neurons of the oculomotor nucleus, which regulate eye movements, are less vulnerable compared to hypoglossal nucleus MNs. Several molecular studies have been performed to understand the different vulnerability of these MNs. By analyzing postmortem samples from ALS patients to other unrelated decedents, the differential genomic pattern between the two nuclei has been profiled. Among identified genes, adenylate cyclase activating polypeptide 1 (ADCYAP1) gene, encoding for pituitary adenylate cyclase-activating polypeptide (PACAP), was found significantly up-regulated in the oculomotor versus hypoglossal nucleus suggesting that it could play a trophic effect on MNs in ALS. In the present review, some aspects regarding the different vulnerability of oculomotor and hypoglossal nucleus to degeneration will be summarized. The distribution and potential role of PACAP on these MNs as studied largely in an animal model of ALS compared to controls, will be discussed.
PubMed: 32848572
DOI: 10.3389/fnins.2020.00805 -
Clinical Anatomy (New York, N.Y.) Jan 2017The oculomotor nerve supplies the extraocular muscles. It also supplies the ciliary and sphincter pupillae muscles through the ciliary ganglion. The nerve fibers leave... (Review)
Review
The oculomotor nerve supplies the extraocular muscles. It also supplies the ciliary and sphincter pupillae muscles through the ciliary ganglion. The nerve fibers leave the midbrain through the most medial part of the cerebral peduncle and enter the interpeduncular cistern. After the oculomotor nerve emerges from the interpeduncular fossa, it enters the cavernous sinus slightly lateral and anterior to the dorsum sellae. It enters the orbit through the superior orbital fissure, after exiting the cavernous sinus, to innervate the extraocular muscles. Therefore, knowledge of the detailed anatomy and pathway of the oculomotor nerve is critical for the management of lesions located in the middle cranial fossa and the clival, cavernous, and orbital regions. This review describes the microsurgical anatomy of the oculomotor nerve and presents pictures illustrating this nerve and its surrounding connective and neurovascular structures. Clin. Anat. 30:21-31, 2017. © 2016 Wiley Periodicals, Inc.
Topics: Humans; Microsurgery; Oculomotor Nerve
PubMed: 27859787
DOI: 10.1002/ca.22811 -
Klinische Monatsblatter Fur... Nov 2012Examinations of eye movements offer an easy clinical method for the diagnosis of disturbances in the pathways for the generation of eye movements including the... (Review)
Review
Examinations of eye movements offer an easy clinical method for the diagnosis of disturbances in the pathways for the generation of eye movements including the extraocular and inner eye muscles. A prerequisite is a good knowledge of the anatomy of the pathways for the generation of eye movements. The oculomotor nucleus represents an important relay station, which contains not only the motoneurons of four extraocular muscles and the levator palpebrae muscle, but also the preganglionic neurons of the ciliary ganglion for the mediation of the pupillary and accommodation response. Recent work about the special anatomy of the extraocular muscles and histochemical findings about the neurons in the Edinger-Westphal nucleus (EW), which indicated that this nucleus does not contain the preganglionic neurons of the ciliary ganglion, led to a new, modified map of the oculomotor nucleus complex. The most serious alteration refers to the location of the preganglionic neurons, which form a group of scattered neurons outside of the EW and now are termed EWpg. In contrast, the traditional cytoarchitectonically defined EW in the human eye contains peptidergic neurons with a completely different function, e.g., stress related, and is therefore termed EWcp (centrally projecting). A knowledge about the exact locations of extraocular motoneurons and preganglionic neurons is essential for the correct interpretation of clinico-anatomic findings.
Topics: Accommodation, Ocular; Animals; Eye Movements; Eyelids; Haplorhini; Humans; Motor Neurons; Nerve Fibers; Neural Pathways; Oculomotor Muscles; Oculomotor Nerve; Reflex, Pupillary; Tegmentum Mesencephali
PubMed: 22996634
DOI: 10.1055/s-0032-1315252 -
Anatomical Record (Hoboken, N.J. : 2007) Mar 2019The oculomotor (OM) complex is a combination of somatic and parasympatethic neurons. The correct development and wiring of this cranial pair is essential to perform...
The oculomotor (OM) complex is a combination of somatic and parasympatethic neurons. The correct development and wiring of this cranial pair is essential to perform basic functions: eyeball and eyelid movements, pupillary constriction, and lens accommodation. The improper formation or function of this nucleus leads pathologies such as strabismus. We describe the OM organization and function in different vertebrate brains, including chick, mouse, and human. The morphological localization is detailed, as well as the spatial relation with the trochlear nucleus in order to adjust some misleading anatomical topographic descriptions. We detailed the signaling processes needed for the specification of the OM neurons. The transcriptional programs driven the specification and differentiation of these neurons are partially determined. We summarized recent genetic studies that have led to the identification of guidance mechanisms involved in the migration, axon pathfinding, and targeting of the OM neurons. Finally, we overviewed the pathology associated to genetic malformations in the OM development and related clinical alterations. Anat Rec, 302:446-451, 2019. © 2018 Wiley Periodicals, Inc.
Topics: Animals; Cell Differentiation; Cell Movement; Chickens; Cranial Nerves; Eye Movements; Humans; Mice; Motor Neurons; Neural Pathways; Oculomotor Nerve
PubMed: 29663710
DOI: 10.1002/ar.23827 -
Annals of the New York Academy of... 1986
Review
Topics: Animals; Capillaries; Cats; Kinetics; Methyldopa; Norepinephrine; Oculomotor Nerve; Perfusion; Pupil; Receptors, Adrenergic; Synapses
PubMed: 3541736
DOI: 10.1111/j.1749-6632.1986.tb23630.x -
Molecular Neurobiology Sep 2017Several efforts have been made to understand the involvement of rapid eye movement (REM) sleep for cognitive processes. Consolidation or retention of recognition...
Several efforts have been made to understand the involvement of rapid eye movement (REM) sleep for cognitive processes. Consolidation or retention of recognition memories is severely disrupted by REM sleep deprivation (REMSD). In this regard, pedunculopontine tegmental nucleus (PPT) and other brainstem nuclei, such as pontine nucleus (Pn) and oculomotor nucleus (OCM), appear to be candidates to take part in this REM sleep circuitry with potential involvement in cognition. Therefore, the objective of this study was to investigate a possible association between the performance of Wistar rats in a declarative memory and PPT, Pn, and OCM activities after different periods of REMSD. We examined c-Fos and choline acetyltransferase (ChaT) expressions as indicators of neuronal activity as well as a familiarity-based memory test. The animals were distributed in groups: control, REMSD, and sleep rebound (REB). At the end of the different REMSD (24, 48, 72, and 96 h) and REB (24 h) time points, the rats were immediately tested in the object recognition test and then the brains were collected. Results indicated that OCM neurons presented an increased activity, due to ChaT-labeling associated with REMSD that negatively correlated (r = -0.32) with the cognitive performance. This suggests the existence of a cholinergic compensatory mechanism within the OCM during REMSD. We also showed that 24 h of REMSD impacted similarly in memory, compared to longer periods of REMSD. These data extend the notion that REM sleep is influenced by areas other than PPT, i.e., Pn and OCM, which could be key players in both sleep processes and cognition.
Topics: Animals; Cholinergic Agents; Cognition; Male; Memory; Neurons; Oculomotor Nuclear Complex; Pedunculopontine Tegmental Nucleus; Proto-Oncogene Proteins c-fos; Rats, Wistar; Sleep Deprivation; Sleep, REM
PubMed: 27660264
DOI: 10.1007/s12035-016-0112-z -
Frontiers in Neuroanatomy 2011The mammalian oculomotor nucleus receives a strong γ-aminobutyric acid (GABA)ergic synaptic input, whereas such projections have rarely been reported in fish. In order...
The mammalian oculomotor nucleus receives a strong γ-aminobutyric acid (GABA)ergic synaptic input, whereas such projections have rarely been reported in fish. In order to determine whether this synaptic organization is preserved across vertebrates, we investigated the GABAergic projections to the oculomotor nucleus in the goldfish by combining retrograde transport of biotin dextran amine, injected into the antidromically identified oculomotor nucleus, and GABA immunohistochemistry. The main source of GABAergic afferents to the oculomotor nucleus was the ipsilateral anterior octaval nucleus, with only a few, if any, GABAergic neurons being located in the contralateral tangential and descending nuclei of the octaval column. In mammals there is a nearly GABAergic inhibitory inputs; thus, the vestibulooculomotor GABAergic circuitry follows a plan that appears to be shared throughout the vertebrate phylogeny. The second major source of GABAergic projections was the rhombencephalic reticular formation, primarily from the medial area but, to a lesser extent, from the inferior area. A few GABAergic oculomotor projecting neurons were also observed in the ipsilateral nucleus of the medial longitudinal fasciculus. The GABAergic projections from neurons located in both the reticular formation surrounding the abducens nucleus and the nucleus of the medial reticular formation have primarily been related to the control of saccadic eye movements. Finally, all retrogradely labeled internuclear neurons of the abducens nucleus, and neurons in the cerebellum (close to the caudal lobe), were negative for GABA. These data suggest that the vestibuloocular and saccadic inhibitory GABAergic systems appear early in vertebrate phylogeny to modulate the firing properties of the oculomotor nucleus motoneurons.
PubMed: 21331170
DOI: 10.3389/fnana.2011.00007 -
Human Brain Mapping Nov 2022Stretch receptors in the extraocular muscles (EOMs) inform the central nervous system about the rotation of one's own eyes in the orbits. Whereas fine control of the...
Stretch receptors in the extraocular muscles (EOMs) inform the central nervous system about the rotation of one's own eyes in the orbits. Whereas fine control of the skeletal muscles hinges critically on proprioceptive feedback, the role of proprioception in oculomotor control remains unclear. Human behavioural studies provide evidence for EOM proprioception in oculomotor control, however, behavioural and electrophysiological studies in the macaque do not. Unlike macaques, humans possess numerous muscle spindles in their EOMs. To find out whether the human oculomotor nuclei respond to proprioceptive feedback we used functional magnetic resonance imaging (fMRI). With their eyes closed, participants placed their right index finger on the eyelid at the outer corner of the right eye. When prompted by a sound, they pushed the eyeball gently and briefly towards the nose. Control conditions separated out motor and tactile task components. The stretch of the right lateral rectus muscle was associated with activation of the left oculomotor nucleus and subthreshold activation of the left abducens nucleus. Because these nuclei control the horizontal movements of the left eye, we hypothesized that proprioceptive stimulation of the right EOM triggered left eye movement. To test this, we followed up with an eye-tracking experiment in complete darkness using the same behavioural task as in the fMRI study. The left eye moved actively in the direction of the passive displacement of the right eye, albeit with a smaller amplitude. Eye tracking corroborated neuroimaging findings to suggest a proprioceptive contribution to ocular alignment.
Topics: Humans; Oculomotor Muscles; Eye Movements; Proprioception; Eye; Feedback, Sensory
PubMed: 36135800
DOI: 10.1002/hbm.26080 -
Anatomy and Embryology 1988By means of retrograde transport of the wheat germ agglutinin-horseradish peroxidase complex, afferent fibres to the lateral reticular nucleus from the oculomotor and...
Afferents to the lateral reticular nucleus from the oculomotor region. II. The oculomotor nucleus, the interstitial nucleus of Cajal and the nucleus of the posterior commissure.
By means of retrograde transport of the wheat germ agglutinin-horseradish peroxidase complex, afferent fibres to the lateral reticular nucleus from the oculomotor and accessory oculomotor nuclei were demonstrated in the cat. Small iontophoretic ejections were made into the main part of the lateral reticular nucleus from a ventral approach. Significant numbers of retrogradely labelled neurons were found bilaterally in all parts of the oculomotor nucleus. The majority was of small size and distributed along the dorsal and lateral boundaries of the nucleus. Some labelled neurons were located just outside these boundaries, in the periaqueductal gray and the adjacent mesencephalic reticular formation. Retrogradely labelled neurons were also found in the accessory oculomotor nuclei: The interstitial nucleus of Cajal featured a substantial number of labelled neurons. Some labelled neurons were consistently found also in the nucleus of the posterior commissure, but no labelled neurons were found in the nucleus of Darkschewitch. The labelled neurons in the interstitial nucleus of Cajal were of different sizes and located bilaterally, mainly in its rostral part. Caudal as well as rostral parts of the main lateral reticular nucleus appear to receive the descending afferents from the oculomotor region, but higher numbers of labelled neurons were found subsequent to ejections in the rostral part. The findings are discussed and some comments are made concerning the lateral reticular nucleus as a possible relay nucleus for oculomotor input to the cerebellum.
Topics: Afferent Pathways; Animals; Brain Mapping; Cats; Cell Count; Horseradish Peroxidase; Neurons, Afferent; Oculomotor Nerve; Reticular Formation; Wheat Germ Agglutinins
PubMed: 3354844
DOI: 10.1007/BF00321138