Biomaterial Database

Inhibitory synaptic inputs to the oculomotor nucleus from vestibulo-ocular-reflex-related nuclei in the rabbit. 1995

P R Wentzel, and C I De Zeeuw, and J C Holstege, and N M Gerrits

Department of Anatomy, Erasmus University Rotterdam, The Netherlands.

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 general ultrastructural characteristics of the neuropil and the types of boutons observed in the rabbit oculomotor nuclei are in general agreement with the descriptions for the oculomotor complex of other mammals. The superior vestibular nucleus projected bilaterally to the superior rectus and inferior oblique subdivisions, and ipsilaterally to the inferior rectus and medial rectus subdivision; the medial vestibular nucleus projected bilaterally to the medial rectus, inferior oblique, inferior rectus and superior rectus subdivisions with a strong contralateral predominance. The abducens nucleus projected contralaterally to the medial rectus subdivision. More than 90% of all the anterogradely labeled terminals from the ipsilateral superior vestibular nucleus were GABAergic. These terminals were characterized by flattened vesicles and symmetric synapses, and they contacted somata, as well as proximal and distal dendrites of motoneurons. All terminals derived from the medial vestibular nucleus the abducens nucleus and the contralateral superior vestibular nucleus were non-GABAergic. These non-GABAergic terminals showed spherical vesicles and asymmetric synapses, and they contacted predominantly distal dendrites. None of the anterogradely labeled terminals from the studied vestibular nuclei or abducens nucleus were glycinergic. 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. Furthermore, it confirms that the projections from the medial vestibular nucleus, the abducens nucleus and the contralateral superior vestibular nucleus are exclusively non-GABAergic.

UI	MeSH Term	Description	Entries
D007150	Immunohistochemistry	Histochemical localization of immunoreactive substances using labeled antibodies as reagents.	Immunocytochemistry,Immunogold Techniques,Immunogold-Silver Techniques,Immunohistocytochemistry,Immunolabeling Techniques,Immunogold Technics,Immunogold-Silver Technics,Immunolabeling Technics,Immunogold Silver Technics,Immunogold Silver Techniques,Immunogold Technic,Immunogold Technique,Immunogold-Silver Technic,Immunogold-Silver Technique,Immunolabeling Technic,Immunolabeling Technique,Technic, Immunogold,Technic, Immunogold-Silver,Technic, Immunolabeling,Technics, Immunogold,Technics, Immunogold-Silver,Technics, Immunolabeling,Technique, Immunogold,Technique, Immunogold-Silver,Technique, Immunolabeling,Techniques, Immunogold,Techniques, Immunogold-Silver,Techniques, Immunolabeling
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
D009435	Synaptic Transmission	The communication from a NEURON to a target (neuron, muscle, or secretory cell) across a SYNAPSE. In chemical synaptic transmission, the presynaptic neuron releases a NEUROTRANSMITTER that diffuses across the synaptic cleft and binds to specific synaptic receptors, activating them. The activated receptors modulate specific ion channels and/or second-messenger systems in the postsynaptic cell. In electrical synaptic transmission, electrical signals are communicated as an ionic current flow across ELECTRICAL SYNAPSES.	Neural Transmission,Neurotransmission,Transmission, Neural,Transmission, Synaptic
D009802	Oculomotor Nerve	The 3d cranial nerve. The oculomotor nerve sends motor fibers to the levator muscles of the eyelid and to the superior rectus, inferior rectus, and inferior oblique muscles of the eye. It also sends parasympathetic efferents (via the ciliary ganglion) to the muscles controlling pupillary constriction and accommodation. The motor fibers originate in the oculomotor nuclei of the midbrain.	Cranial Nerve III,Third Cranial Nerve,Nerve III,Nervus Oculomotorius,Cranial Nerve IIIs,Cranial Nerve, Third,Cranial Nerves, Third,Nerve IIIs,Nerve, Oculomotor,Nerve, Third Cranial,Nerves, Oculomotor,Nerves, Third Cranial,Oculomotor Nerves,Oculomotorius, Nervus,Third Cranial Nerves
D011817	Rabbits	A burrowing plant-eating mammal with hind limbs that are longer than its fore limbs. It belongs to the family Leporidae of the order Lagomorpha, and in contrast to hares, possesses 22 instead of 24 pairs of chromosomes.	Belgian Hare,New Zealand Rabbit,New Zealand Rabbits,New Zealand White Rabbit,Rabbit,Rabbit, Domestic,Chinchilla Rabbits,NZW Rabbits,New Zealand White Rabbits,Oryctolagus cuniculus,Chinchilla Rabbit,Domestic Rabbit,Domestic Rabbits,Hare, Belgian,NZW Rabbit,Rabbit, Chinchilla,Rabbit, NZW,Rabbit, New Zealand,Rabbits, Chinchilla,Rabbits, Domestic,Rabbits, NZW,Rabbits, New Zealand,Zealand Rabbit, New,Zealand Rabbits, New,cuniculus, Oryctolagus
D012027	Reflex, Vestibulo-Ocular	A reflex wherein impulses are conveyed from the cupulas of the SEMICIRCULAR CANALS and from the OTOLITHIC MEMBRANE of the SACCULE AND UTRICLE via the VESTIBULAR NUCLEI of the BRAIN STEM and the median longitudinal fasciculus to the OCULOMOTOR NERVE nuclei. It functions to maintain a stable retinal image during head rotation by generating appropriate compensatory EYE MOVEMENTS.	Vestibulo-Ocular Reflex,Reflex, Vestibuloocular,Reflexes, Vestibo-Ocular,Reflexes, Vestibuloocular,Reflex, Vestibulo Ocular,Reflexes, Vestibo Ocular,Vestibo-Ocular Reflexes,Vestibulo Ocular Reflex,Vestibuloocular Reflex,Vestibuloocular Reflexes
D001931	Brain Mapping	Imaging techniques used to colocalize sites of brain functions or physiological activity with brain structures.	Brain Electrical Activity Mapping,Functional Cerebral Localization,Topographic Brain Mapping,Brain Mapping, Topographic,Functional Cerebral Localizations,Mapping, Brain,Mapping, Topographic Brain
D006735	Horseradish Peroxidase	An enzyme isolated from horseradish which is able to act as an antigen. It is frequently used as a histochemical tracer for light and electron microscopy. Its antigenicity has permitted its use as a combined antigen and marker in experimental immunology.	Alpha-Peroxidase,Ferrihorseradish Peroxidase,Horseradish Peroxidase II,Horseradish Peroxidase III,Alpha Peroxidase,II, Horseradish Peroxidase,III, Horseradish Peroxidase,Peroxidase II, Horseradish,Peroxidase III, Horseradish,Peroxidase, Ferrihorseradish,Peroxidase, Horseradish
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D014909	Wheat Germ Agglutinins	Lectins purified from the germinating seeds of common wheat (Triticum vulgare); these bind to certain carbohydrate moieties on cell surface glycoproteins and are used to identify certain cell populations and inhibit or promote some immunological or physiological activities. There are at least two isoforms of this lectin.	Agglutinins, Wheat Germ,Lectins, Triticum Vulgare,Lectins, Wheat Germ,Triticum Vulgare Lectin,Triticum Vulgare Lectins,Wheat Germ Agglutinin,Wheat Germ Lectin,Wheat Germ Lectins,Wheat Germ Agglutinin Isolectin 1,Wheat Germ Agglutinin Isolectin 2,Agglutinin, Wheat Germ,Germ Agglutinin, Wheat,Germ Lectin, Wheat,Lectin, Triticum Vulgare,Lectin, Wheat Germ,Vulgare Lectin, Triticum