Biomaterial Database

Influence of excitatory amino acid receptor subtypes on the electrophysiological activity of dopaminergic and nondopaminergic neurons in rat substantia nigra. 1994

J Zhang, and L A Chiodo, and A S Freeman

Department of Psychiatry, Wayne State University School of Medicine, Detroit, Michigan.

In vivo electrophysiological recording methods were used to evaluate the effects of selective and nonselective agonists for excitatory amino acid (EAA) receptor subtypes on the activity of dopaminergic (DA) and nondopaminergic (non-DA) neurons in the substantia nigra of chloral hydrate-anesthetized rats. Microiontophoretic administration of (+/-)-alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA), 2-carboxy-4-(1-methyl-ethenyl)-3-pyrrolidinacetate (kainate), N-methyl-D-aspartate (NMDA) and glutamate excited neurons with an apparent rank order of potency of AMPA = kainate = glutamate > NMDA on DA neurons, and AMPA = kainate > glutamate = NMDA on non-DA neurons. These agonists also changed the firing pattern of DA neurons, which displayed an increase in burst-firing and a reduction in the regularity of the firing pattern. Regularity of firing was indexed by the variation coefficient of a sample of interspike intervals. The apparent potencies of the four agonists to increase burst-firing and variation coefficient were similar to their potencies to increase neuronal firing rate. Blockade of NMDA receptor function by coiontophoresis of 5R,10S-(+/-)-5-methyl-10,11-dihydro-5H-dibenzo[and]cyclohepten-5,1 0-imine hydrogen maleate (MK-801), a selective noncompetitive NMDA antagonist, did not alter kainate-induced changes in firing rate and firing pattern, which indicated that kainate-induced increases in burst-firing were not dependent on concomitant NMDA receptor activation by endogenous excitatory amino acid.(ABSTRACT TRUNCATED AT 250 WORDS)

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
D007608	Kainic Acid	(2S-(2 alpha,3 beta,4 beta))-2-Carboxy-4-(1-methylethenyl)-3-pyrrolidineacetic acid. Ascaricide obtained from the red alga Digenea simplex. It is a potent excitatory amino acid agonist at some types of excitatory amino acid receptors and has been used to discriminate among receptor types. Like many excitatory amino acid agonists it can cause neurotoxicity and has been used experimentally for that purpose.	Digenic Acid,Kainate,Acid, Digenic,Acid, Kainic
D008297	Male		Males
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
D004298	Dopamine	One of the catecholamine NEUROTRANSMITTERS in the brain. It is derived from TYROSINE and is the precursor to NOREPINEPHRINE and EPINEPHRINE. Dopamine is a major transmitter in the extrapyramidal system of the brain, and important in regulating movement. A family of receptors (RECEPTORS, DOPAMINE) mediate its action.	Hydroxytyramine,3,4-Dihydroxyphenethylamine,4-(2-Aminoethyl)-1,2-benzenediol,Dopamine Hydrochloride,Intropin,3,4 Dihydroxyphenethylamine,Hydrochloride, Dopamine
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.
D005971	Glutamates	Derivatives of GLUTAMIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the 2-aminopentanedioic acid structure.	Glutamic Acid Derivatives,Glutamic Acids,Glutaminic Acids
D000200	Action Potentials	Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.	Spike Potentials,Nerve Impulses,Action Potential,Impulse, Nerve,Impulses, Nerve,Nerve Impulse,Potential, Action,Potential, Spike,Potentials, Action,Potentials, Spike,Spike Potential
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
D013378	Substantia Nigra	The black substance in the ventral midbrain or the nucleus of cells containing the black substance. These cells produce DOPAMINE, an important neurotransmitter in regulation of the sensorimotor system and mood. The dark colored MELANIN is a by-product of dopamine synthesis.	Nigra, Substantia,Nigras, Substantia,Substantia Nigras