Biomaterial Database

Effects of excitatory and inhibitory amino acids on neuronal discharges in the cultured suprachiasmatic nucleus. 1993

N P Bos, and M Mirmiran

Netherlands Institute for Brain Research, Amsterdam.

The influence of amino acids on neuronal activity was studied microiontophoretically in the cultured suprachiasmatic nucleus (SCN). Three types of SCN neurons could be characterized: silent (glutamate responsive), irregular, and regular neurons. Glutamate excited about 70% of the regular and 60% of the irregular cells. GABA inhibited both the spontaneous and the glutamate-evoked activity of more than 90% of all three types of SCN neurons. MK-801 partially blocked glutamate responses. N-acetyl-aspartyl-glutamate (NAAG), a new neurotransmitter found in the retinohypothalamic fibers, directly increased firing rate and potentiated glutamate responses in the SCN neurons that were studied. These results indicate the potential significance of the amino acids in neuronal transmission within the biological clock.

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
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
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
D000596	Amino Acids	Organic compounds that generally contain an amino (-NH2) and a carboxyl (-COOH) group. Twenty alpha-amino acids are the subunits which are polymerized to form proteins.	Amino Acid,Acid, Amino,Acids, Amino
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
D013493	Suprachiasmatic Nucleus	An ovoid densely packed collection of small cells of the anterior hypothalamus lying close to the midline in a shallow impression of the OPTIC CHIASM.	Hypothalamic Suprachiasmatic Nuclei,Hypothalamic Suprachiasmatic Nucleus,Suprachiasmatic Nuclei,Suprachiasmatic Nuclei, Hypothalamic,Suprachiasmatic Nucleus, Hypothalamic
D017208	Rats, Wistar	A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.	Wistar Rat,Rat, Wistar,Wistar Rats
D046508	Culture Techniques	Methods of maintaining or growing biological materials in controlled laboratory conditions. These include the cultures of CELLS; TISSUES; organs; or embryo in vitro. Both animal and plant tissues may be cultured by a variety of methods. Cultures may derive from normal or abnormal tissues, and consist of a single cell type or mixed cell types.	Culture Technique,Technique, Culture,Techniques, Culture