HIPPOCAMPUS AND LOCUS COERULEUS ACTIVITY ON RATS CHRONICALLY TREATED WITH DIAZEPAM

MARIELA F. PÉREZ.; FERNANDO J. NASIF; GERARDO R MARCHESINI ; LAURA MAGLIO; OSCAR A RAMIREZ

PHARMACOLOGY BIOCHEMISTRY AND BEHAVIOR

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2001 vol. 69 p. 1 - 1

0091-3057

he neural mechanisms underlying benzodiazepine (BZD) dependence remain equivocal. The present studies tested the hypothesis that similar neural circuitry might be involved in the effects of chronic 7-chloro-1-methyl-5-phenyl-3H-1,4-benzodiazepine-2(1H)-one, diazepam (DZ, Roche), administration and withdrawal. The results of our study showed an increased hippocampal synaptic plasticity in slices from rats chronically treated with DZ (5 mg/kg/18 days), assessed as a decrease of the threshold in the stimulation rate for long-term potentiation (LTP) elicitation. Rats with the same schedule of DZ administration but without signs of withdrawal behaved similarly to vehicle-treated ones (VEH), in the threshold to induce LTP. Furthermore, the activity of locus coeruleus (LC) norepinephrine (NE) neurons in rats tested 24 h after the last DZ injection showed a significant increase. On the other hand, rats that after chronic DZ administration did not develop signs of withdrawal and exhibited a si