Biomaterial Database

Asymmetries of vertical vestibular nystagmus in the cat. 1981

C Darlot, and J López-Barneo, and D Tracey

In the cat, the asymmetry of vertical nystagmus in response to a rotation around the Y-axis has been characterized by measuring the beat frequency and gain of vestibulo-ocular reflexes in each direction (upward and downward). Sinusoidal variations of head velocity or velocity steps have been applied under three visual conditions (a) in darkness (pure vestibular stimulation); (b) in the light (mixed vestibular and optokinetic stimulation); (c) with a mirror placed in front of the animal; since the mirror image moved with the head, the animal was provided with a stable visual cue (stabilized vision). In all three conditions, beat frequency and gain were greater for downward than for upward nystagmus (the direction refers to that of the quick phase). In darkness, the characteristics of postrotatory nystagmus suggested a greater time constant for downward than for upward vestibulo-ocular reflexes. In the light, both stimuli acted synergistically. In stabilized vision, upward vestibular nystagmus was preferentially suppressed, suggesting an algebraic summation of the effects arising from both kinds of stimuli.

UI	MeSH Term	Description	Entries
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
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
D012018	Reflex	An involuntary movement or exercise of function in a part, excited in response to a stimulus applied to the periphery and transmitted to the brain or spinal cord.
D002415	Cats	The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)	Felis catus,Felis domesticus,Domestic Cats,Felis domestica,Felis sylvestris catus,Cat,Cat, Domestic,Cats, Domestic,Domestic Cat
D004292	Dominance, Cerebral	Dominance of one cerebral hemisphere over the other in cerebral functions.	Cerebral Dominance,Hemispheric Specialization,Dominances, Cerebral,Specialization, Hemispheric
D005133	Eye Movements	Voluntary or reflex-controlled movements of the eye.	Eye Movement,Movement, Eye,Movements, Eye
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
D012399	Rotation	Motion of an object in which either one or more points on a line are fixed. It is also the motion of a particle about a fixed point. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Clinorotation,Clinorotations,Rotations
D014725	Vestibular Nerve	The vestibular part of the 8th cranial nerve (VESTIBULOCOCHLEAR NERVE). The vestibular nerve fibers arise from neurons of Scarpa's ganglion and project peripherally to vestibular hair cells and centrally to the VESTIBULAR NUCLEI of the BRAIN STEM. These fibers mediate the sense of balance and head position.	Scarpa's Ganglion,Ganglion, Scarpa's,Nerve, Vestibular,Nerves, Vestibular,Scarpa Ganglion,Scarpas Ganglion,Vestibular Nerves
D014796	Visual Perception	The selecting and organizing of visual stimuli based on the individual's past experience.	Visual Processing,Perception, Visual,Processing, Visual