Area-dependent changes in GABAergic function after acute and chronic cold stress.
(1) The function of the gamma-aminobutyric acid (GABA)ergic system in certain areas of the rat brain was investigated after acute and chronic cold stress. (2) GABA concentration, [3H]GABA uptake and the activity of the synthesis enzyme glutamate decarboxylase (GAD) were measured. (3) Acute stress: (a) reduced GABA concentration in the corpus striatum (29%); (b) decreased GAD activity (under non-saturating substrate concentration) in the olfactory bulbs (24%); (c) diminished neuronal uptake of [3H]GABA in the frontal cerebral cortex (65%), hypothalamus (86%) and olfactory bulbs (82%). (4) Chronic stress: (a) reduced the endogenous levels of GABA in the frontal cerebral cortex (51%), hypothalamus (26%) and olfactory bulbs (15%); (b) decreased GAD activity in the corpus striatum (32%) and olfactory bulbs (34%); (c) decreased neuronal uptake of [3H]GABA in the hypothalamus (83%). (5) These findings suggest that compensatory changes may develop in the GABAergic system after chronic stress.
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Instituto de Investigaciones Farmacológicas [ININFA], Consejo Nacional de Investigaciones Cientificas y Técnicas [CONICET], Buenos Aires, Argentina.
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D000208:Acute Disease; D000818:Animals; D002540:Cerebral Cortex / Q000201:enzymology / Q000378:metabolism; D002908:Chronic Disease; D003080:Cold Temperature; D005968:Glutamate Decarboxylase / Q000378:metabolism; D007031:Hypothalamus / Q000201:enzymology / Q000378:metabolism; D008297:Male; D009474:Neurons / Q000201:enzymology / Q000378:metabolism; D009830:Olfactory Bulb / Q000201:enzymology / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013312:Stress, Physiological / Q000378:metabolism*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D005680:gamma-Aminobutyric Acid; D005968:Glutamate Decarboxylase