A possible inhibitory action of baclofen on hippocampus GABAergic neurones.
1. The function of the gamma-aminobutyric acid (GABA)ergic system in certain areas of the rat brain was investigated after baclofen treatment (30 mg/kg for 4 days). 2. Two h after the last dose of baclofen GAD activity was reduced in the hippocampus without changes in GABA levels. 24 h after baclofen, GAD activity was increased and the GABA content was decreased. 3. 48 h after the last dose both parameters returned to control values. 4. These results were not observed in any of the other areas investigated: frontal cerebral cortex, corpus striatum, olfactory bulbs, and medio basal hypothalamus. 5. In conclusion, the present study shows that baclofen 30 mg/kg for 4 days, induces an inhibitory action on hippocampus GABAergic neurones, which begins to disappear after 24 h free of drug.
Balerio
G N
GN
Instituto de Investigaciones Farmacológicas, CONICET, Cátedra de Farmacologia, Fac. de Farmacia y Bioquimica (UBA), Buenos Aires, Argentina.
Otero Losada
M E
ME
Rubio
M C
MC
D000818:Animals; D001418:Baclofen / Q000494:pharmacology*; D015415:Biomarkers; D001921:Brain / Q000187:drug effects / Q000201:enzymology; D005968:Glutamate Decarboxylase / Q000037:antagonists & inhibitors / Q000378:metabolism; D006624:Hippocampus / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D066298:In Vitro Techniques; D008297:Male; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D013050:Spectrometry, Fluorescence; D005680:gamma-Aminobutyric Acid / Q000378:metabolism / Q000502:physiology*
D015415:Biomarkers; D005680:gamma-Aminobutyric Acid; D005968:Glutamate Decarboxylase; D001418:Baclofen