Muscarinic receptors regulate extracellular glutamate levels in the rat striatum: an in vivo microdialysis study. 1998

S M Rawls, and J F Mcginty
Department of Anatomy and Cell Biology, East Carolina University School of Medicine, Greenville, North Carolina, USA.

Regulation of extracellular glutamate levels by muscarinic receptors in the striatum of unanesthetized rats was investigated by microdialysis. Extracellular glutamate levels were elevated by intrastriatal perfusion of L-trans-pyrrolidine-2,4-dicarboxylic acid (L-trans-PDC), a competitive substrate of plasma membrane excitatory amino acid transporters. The nonselective muscarinic agonist, oxotremorine (0.5-54 microM) significantly decreased L-trans-PDC-evoked glutamate levels in a concentration-dependent manner. Scopolamine (0.1-10 microM), a nonselective muscarinic receptor antagonist, reversed the effect of oxotremorine, which confirms that muscarinic receptor activation mediated the reduction of L-trans-PDC-evoked glutamate levels. In addition, scopolamine (10 microM) significantly elevated basal extracellular glutamate levels, an effect prevented by oxotremorine, which suggests that acetylcholine tonically regulates glutamatergic transmission in the striatum. Previous data from this laboratory have shown that L-trans-PDC-evoked glutamate levels are partially calcium-dependent. The present study demonstrated that attenuation of L-trans-PDC-evoked glutamate levels by reduced calcium was not altered by oxotremorine. Therefore, it is likely that muscarinic receptors regulate calcium-dependent glutamate release evoked by L-trans-PDC.

UI MeSH Term Description Entries
D008297 Male Males
D010095 Oxotremorine A non-hydrolyzed muscarinic agonist used as a research tool. Oxytremorine
D011759 Pyrrolidines Compounds also known as tetrahydropyridines with general molecular formula (CH2)4NH. Tetrahydropyridine,Tetrahydropyridines
D011976 Receptors, Muscarinic One of the two major classes of cholinergic receptors. Muscarinic receptors were originally defined by their preference for MUSCARINE over NICOTINE. There are several subtypes (usually M1, M2, M3....) that are characterized by their cellular actions, pharmacology, and molecular biology. Muscarinic Acetylcholine Receptors,Muscarinic Receptors,Muscarinic Acetylcholine Receptor,Muscarinic Receptor,Acetylcholine Receptor, Muscarinic,Acetylcholine Receptors, Muscarinic,Receptor, Muscarinic,Receptor, Muscarinic Acetylcholine,Receptors, Muscarinic Acetylcholine
D002118 Calcium A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes. Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D003342 Corpus Striatum Striped GRAY MATTER and WHITE MATTER consisting of the NEOSTRIATUM and paleostriatum (GLOBUS PALLIDUS). It is located in front of and lateral to the THALAMUS in each cerebral hemisphere. The gray substance is made up of the CAUDATE NUCLEUS and the lentiform nucleus (the latter consisting of the GLOBUS PALLIDUS and PUTAMEN). The WHITE MATTER is the INTERNAL CAPSULE. Lenticular Nucleus,Lentiform Nucleus,Lentiform Nuclei,Nucleus Lentiformis,Lentiformis, Nucleus,Nuclei, Lentiform,Nucleus, Lenticular,Nucleus, Lentiform,Striatum, Corpus
D003998 Dicarboxylic Acids Acyclic acids that contain two carboxyl groups and have the formula HO2C-R-CO2H, where R may be an aromatic or aliphatic group. Acids, Dicarboxylic
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
D012601 Scopolamine An alkaloid from SOLANACEAE, especially DATURA and SCOPOLIA. Scopolamine and its quaternary derivatives act as antimuscarinics like ATROPINE, but may have more central nervous system effects. Its many uses include an anesthetic premedication, the treatment of URINARY INCONTINENCE and MOTION SICKNESS, an antispasmodic, and a mydriatic and cycloplegic. Hyoscine,Scopolamine Hydrobromide,Boro-Scopol,Isopto Hyoscine,Kwells,Scoburen,Scopace,Scopoderm TTS,Scopolamine Cooper,Transderm Scop,Transderm-V,Travacalm HO,Vorigeno,Boro Scopol,Transderm V
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

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