Endogenous glutamate-taurine interaction in striatum and nucleus accumbens of the freely moving rat: studies during the normal process of aging.
Using microdialysis, the effects of endogenous glutamate on extracellular concentrations of taurine, in striatum and nucleus accumbens of the awake rat during the normal process of aging were investigated. The glutamate uptake inhibitor L-trans-pyrrolidine-2,4-dicarboxylic acid (PDC) was perfused through the microdialysis probe to increase the endogenous concentration of glutamate. Young (2-4 months), middle aged (12-14 months), aged (27-32 months) and very aged (37 months) male Wistar rats were used. PDC (1, 2 and 4 mM) produced a dose-related increase of extracellular concentrations of glutamate and taurine in striatum and nucleus accumbens in all groups of age. Increases of glutamate, but not of taurine, decreased during aging in striatum. In nucleus accumbens there were no age-related changes in the increases of glutamate and taurine induced by PDC. In all age groups, increases of extracellular taurine were significantly correlated with increases of extracellular glutamate. However, when these taurine-glutamate correlations for all groups of age were compared, no statistical differences were found. These results show first that a decrease in the increases of glutamate produced by the glutamate reuptake inhibitor in striatum, but not in nucleus accumbens, is produced by age; second that glutamate-taurine interaction in striatum and nucleus accumbens does not change during the normal process of aging.
Del Arco
A
A
Department of Physiology, Faculty of Medicine, University Complutense, Cuidad Universitaria, s/n 28040 Madrid, Spain.
Segovia
G
G
Prieto
L
L
Mora
F
F
D000375:Aging / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism*; D003998:Dicarboxylic Acids / Q000494:pharmacology; D018698:Glutamic Acid / Q000187:drug effects / Q000378:metabolism*; D008124:Locomotion / Q000187:drug effects / Q000502:physiology*; D008297:Male; D017551:Microdialysis; D014179:Neurotransmitter Uptake Inhibitors / Q000494:pharmacology; D009714:Nucleus Accumbens / Q000187:drug effects / Q000378:metabolism*; D011759:Pyrrolidines / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013654:Taurine / Q000187:drug effects / Q000378:metabolism*
D003998:Dicarboxylic Acids; D014179:Neurotransmitter Uptake Inhibitors; D011759:Pyrrolidines; D013654:Taurine; D018698:Glutamic Acid; C083486:pyrrolidine-2,4-dicarboxylic acid