Biomaterial Database

The neurotransmitter of inhibitory synaptic inputs on inhibitory burst neurons (IBNs) controlling vestibular nystagmus in the cat. 1993

T Yabe, and N Furuya

Department of Otorhinolaryngology, Teikyo University School of Medicine, Tokyo, Japan.

In the pontine neural networks that govern vestibular nystagmus in the cat, inhibitory burst neurons (IBNs) are known to fire in bursts during the quick phase, and to suppress firing of the abducens motoneurons on the contralateral side. The present experiments were designed to identify the neurotransmitter controlling the burst firing pattern of IBNs. Inhibitory burst neuron activity was recorded extracellularly, and various chemicals were applied to the IBNs iontophoretically through multibarrel micropipettes. GABA and muscimol (a GABAA-receptor agonist) strongly suppressed IBN activity and eliminated the burst pattern. Bicuculline (a GABAA-receptor antagonist) increased the firing of IBNs and suppressed the inhibitory effect of GABA when applied simultaneously. Although baclofen (a GABAB-receptor agonist) had no inhibitory effect, it slightly shortened the duration of burst firing. Neither glycine nor serotonin, other inhibitory transmitter candidates, nor their respective antagonists, strychnine and methysergide, had any effect. Systemically administered picrotoxin prevented the GABA-induced suppression of IBNs. These results suggest that IBNs possess GABAA receptors and are controlled by higher GABA-liberating neurons and Cl- channels.

UI	MeSH Term	Description	Entries
D007478	Iontophoresis	Therapeutic introduction of ions of soluble salts into tissues by means of electric current. In medical literature it is commonly used to indicate the process of increasing the penetration of drugs into surface tissues by the application of electric current. It has nothing to do with ION EXCHANGE; AIR IONIZATION nor PHONOPHORESIS, none of which requires current.	Iontophoreses
D009433	Neural Inhibition	The function of opposing or restraining the excitation of neurons or their target excitable cells.	Inhibition, Neural
D009475	Neurons, Afferent	Neurons which conduct NERVE IMPULSES to the CENTRAL NERVOUS SYSTEM.	Afferent Neurons,Afferent Neuron,Neuron, Afferent
D009759	Nystagmus, Pathologic	Involuntary movements of the eye that are divided into two types, jerk and pendular. Jerk nystagmus has a slow phase in one direction followed by a corrective fast phase in the opposite direction, and is usually caused by central or peripheral vestibular dysfunction. Pendular nystagmus features oscillations that are of equal velocity in both directions and this condition is often associated with visual loss early in life. (Adams et al., Principles of Neurology, 6th ed, p272)	Convergence Nystagmus,Horizontal Nystagmus,Jerk Nystagmus,Pendular Nystagmus,Periodic Alternating Nystagmus,Rotary Nystagmus,See-Saw Nystagmus,Vertical Nystagmus,Conjugate Nystagmus,Dissociated Nystagmus,Fatigable Positional Nystagmus,Multidirectional Nystagmus,Non-Fatigable Positional Nystagmus,Permanent Nystagmus,Rebound Nystagmus,Retraction Nystagmus,Rotational Nystagmus,Spontaneous Ocular Nystagmus,Symptomatic Nystagmus,Temporary Nystagmus,Unidirectional Nystagmus,Non Fatigable Positional Nystagmus,Nystagmus, Conjugate,Nystagmus, Convergence,Nystagmus, Dissociated,Nystagmus, Fatigable Positional,Nystagmus, Horizontal,Nystagmus, Jerk,Nystagmus, Multidirectional,Nystagmus, Non-Fatigable Positional,Nystagmus, Pendular,Nystagmus, Periodic Alternating,Nystagmus, Permanent,Nystagmus, Rebound,Nystagmus, Retraction,Nystagmus, Rotary,Nystagmus, Rotational,Nystagmus, See-Saw,Nystagmus, Spontaneous Ocular,Nystagmus, Symptomatic,Nystagmus, Temporary,Nystagmus, Unidirectional,Nystagmus, Vertical,Ocular Nystagmus, Spontaneous,Pathologic Nystagmus,Positional Nystagmus, Non-Fatigable,See Saw Nystagmus
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
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
D018377	Neurotransmitter Agents	Substances used for their pharmacological actions on any aspect of neurotransmitter systems. Neurotransmitter agents include agonists, antagonists, degradation inhibitors, uptake inhibitors, depleters, precursors, and modulators of receptor function.	Nerve Transmitter Substance,Neurohormone,Neurohumor,Neurotransmitter Agent,Nerve Transmitter Substances,Neurohormones,Neurohumors,Neuromodulator,Neuromodulators,Neuroregulator,Neuroregulators,Neurotransmitter,Neurotransmitters,Substances, Nerve Transmitter,Transmitter Substances, Nerve,Substance, Nerve Transmitter,Transmitter Substance, Nerve