Dynamics of rabbit vestibular nucleus neurons and the influence of the flocculus. 1995

J S Stahl, and J I Simpson
Department of Physiology and Neuroscience, New York University Medical Center, New York 10016, USA.

1. We recorded single vestibular nucleus neurons shown by electrical stimulation to receive floccular inhibition [flocculus receiving neurons (FRNs)] and/or to project toward midbrain motoneuronal pools [midbrain projecting neurons (MPNs)] in awake, head-fixed rabbits during compensatory eye movements. Stimuli included head rotation in the light, head rotation in the dark, and rotation of an optokinetic drum about the animal. We employed sinusoidal and triangular position profiles in the 0.05- to 0.8-Hz frequency band. We also examined transient responses to step changes in eye position. 2. We found identified vestibular nucleus cells (i.e., FRN/non-MPNs, FRN/MPNs, and non-FRN/MPNs) in the parvocellular and magnocellular portions of the medial vestibular nucleus, at the rostrocaudal level of the dorsal acoustic stria. 3. All identified vestibular nucleus neurons were excited during ipsilateral (relative to side of recording) head rotation and contralateral eye rotation. 4. The neuronal firing rates could be related to eye position and its time derivatives, and that relationship could be approximated by a two-pole, one-zero linear transfer function. As with abducens neurons, a more detailed approximation requires inclusion of two nonlinearities-a hysteresis and a variable sensitivity term that increases as eye movement amplitude decreases. 5. When the vestibuloocular reflex is suppressed by a conflicting full-field visual stimulus [visual vestibular conflict condition (VVC)], vestibular nucleus neuron modulation is largely suppressed. The remaining modulation is motoric in nature, because it can be related to the residual eye movements. Cells with "sensory vestibular signals," i.e., cells whose modulation during VVC correlates better with head rotation than eye movement, were not encountered. 6. We examined the dependence of firing rate parameters on stimulus modality. All neurons exhibited increased phase lead with respect to abducens nucleus neurons during stimuli involving head rotation. This finding could indicate that vestibular-derived inputs are inhomogeneously distributed on premotor neurons and that the studied premotor population receives a stronger vestibular input than another premotor group, not recorded in the current experiments. 7. FRNs and non-FRNs were similar in their qualitative response to the fast phases, the applicability of the two-pole, one-zero transfer function, hysteresis, and the amplitude nonlinearity. 8. FRNs differed from non-FRNs in having a phase advanced firing rate at all stimulus frequencies during visual and vestibular stimuli. The phase difference suggests that one role of the rabbit flocculus is to regulate phase of the net premotor signal.

UI MeSH Term Description Entries
D008636 Mesencephalon The middle of the three primitive cerebral vesicles of the embryonic brain. Without further subdivision, midbrain develops into a short, constricted portion connecting the PONS and the DIENCEPHALON. Midbrain contains two major parts, the dorsal TECTUM MESENCEPHALI and the ventral TEGMENTUM MESENCEPHALI, housing components of auditory, visual, and other sensorimoter systems. Midbrain,Mesencephalons,Midbrains
D009474 Neurons The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM. Nerve Cells,Cell, Nerve,Cells, Nerve,Nerve Cell,Neuron
D010775 Photic Stimulation Investigative technique commonly used during ELECTROENCEPHALOGRAPHY in which a series of bright light flashes or visual patterns are used to elicit brain activity. Stimulation, Photic,Visual Stimulation,Photic Stimulations,Stimulation, Visual,Stimulations, Photic,Stimulations, Visual,Visual Stimulations
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
D002531 Cerebellum The part of brain that lies behind the BRAIN STEM in the posterior base of skull (CRANIAL FOSSA, POSTERIOR). It is also known as the "little brain" with convolutions similar to those of CEREBRAL CORTEX, inner white matter, and deep cerebellar nuclei. Its function is to coordinate voluntary movements, maintain balance, and learn motor skills. Cerebella,Corpus Cerebelli,Parencephalon,Cerebellums,Parencephalons
D004558 Electric Stimulation Use of electric potential or currents to elicit biological responses. Stimulation, Electric,Electrical Stimulation,Electric Stimulations,Electrical Stimulations,Stimulation, Electrical,Stimulations, Electric,Stimulations, Electrical
D005260 Female Females
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
D014726 Vestibular Nuclei The four cellular masses in the floor of the fourth ventricle giving rise to a widely dispersed special sensory system. Included is the superior, medial, inferior, and LATERAL VESTIBULAR NUCLEUS. (From Dorland, 27th ed) Schwalbe Nucleus,Vestibular Nucleus, Medial,Schwalbe's Nucleus,Medial Vestibular Nucleus,Nuclei, Vestibular,Nucleus, Medial Vestibular,Nucleus, Schwalbe,Nucleus, Schwalbe's,Schwalbes Nucleus

Related Publications

J S Stahl, and J I Simpson
January 2001, Brain research,
J S Stahl, and J I Simpson
March 2002, The Journal of neuroscience : the official journal of the Society for Neuroscience,
J S Stahl, and J I Simpson
January 1999, Neuroscience and behavioral physiology,
J S Stahl, and J I Simpson
March 1969, Journal of ultrastructure research,
J S Stahl, and J I Simpson
October 2015, Cerebellum (London, England),
Copied contents to your clipboard!