Biomaterial Database

5-HT1A receptor-mediated inhibition of lateral vestibular nucleus neurons projecting to the abducens nucleus. 1994

T Kishimoto, and T Yamanaka, and T Amano, and N Todo, and M Sasa

Department of Pharmacology, Faculty of Medicine, Kyoto University, Japan.

Electrophysiological studies were performed using cats anesthetized with alpha-chloralose, to elucidate the 5-hydroxytryptamine (5-HT) receptor subtypes involved in the 5-HT-induced inhibition of the lateral vestibular nucleus (LVN) neurons projecting to or through the abducens nucleus. The effects of 5-HT receptor subtype agonists and antagonist were examined in polysynaptic neurons activated by stimulation of the ipsilateral abducens nucleus (IAN) antidromically, since these neurons are sensitive to 5-HT as shown in our previous study. Iontophoretic application of 5-HT and 8-hydroxy-2-(di-n-propylamino)tetrain (8-OH-DPAT), a selective 5-HT1A agonist, inhibited orthodromic spikes elicited by vestibular nerve stimulation in the majority of polysynaptic neurons activated by stimulation of ipsilateral IAN antidromically. There was a good correlation between the effects of 5-HT and 8-OH-DPAT. Iontophoretically applied 5-HT and 8-OH-DPAT also inhibited glutamate-induced firing in these neurons. Simultaneous application of 1-(2-methoxyphenyl)-4-[4-(2-phthalimido)butyl]piperazine (NAN-190), a 5-HT1A agonist/antagonist, significantly antagonized the 8-OH-DPAT-induced inhibition of glutamate-induced firing, although NAN-190 alone also caused weak suppression of glutamate-induced firing. Microiontophoretically applied 1-(3-chlorophenyl)piperazine (mCPP), a 5-HT1B agonist inhibited the orthodromic spike elicited by vestibular nerve stimulation and glutamate-induced firing in only a small number of the LVN neurons. 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI), a 5-HT2 agonist, rarely affected these neurons. We postulate that postsynaptically located 5-HT1A receptors are mainly involved in the 5-HT-induced inhibition of polysynaptic neurons projecting in the region of the IAN.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D009433	Neural Inhibition	The function of opposing or restraining the excitation of neurons or their target excitable cells.	Inhibition, Neural
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
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
D010879	Piperazines	Compounds that are derived from PIPERAZINE.
D011985	Receptors, Serotonin	Cell-surface proteins that bind SEROTONIN and trigger intracellular changes which influence the behavior of cells. Several types of serotonin receptors have been recognized which differ in their pharmacology, molecular biology, and mode of action.	5-HT Receptor,5-HT Receptors,5-Hydroxytryptamine Receptor,5-Hydroxytryptamine Receptors,Receptors, Tryptamine,Serotonin Receptor,Serotonin Receptors,Tryptamine Receptor,Tryptamine Receptors,Receptors, 5-HT,Receptors, 5-Hydroxytryptamine,5 HT Receptor,5 HT Receptors,5 Hydroxytryptamine Receptor,5 Hydroxytryptamine Receptors,Receptor, 5-HT,Receptor, 5-Hydroxytryptamine,Receptor, Serotonin,Receptor, Tryptamine,Receptors, 5 HT,Receptors, 5 Hydroxytryptamine
D001921	Brain	The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.	Encephalon
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
D004594	Electrophysiology	The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.
D005260	Female		Females