Hippocampus and locus coeruleus activity on rats chronically treated with diazepam.
Pharmacol Biochem Behav
; 69(3-4): 431-8, 2001.
Article
em En
| MEDLINE
| ID: mdl-11509201
The 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 similar pattern of discharge on LC-NE nucleus compared with their controls. We conclude that chronic DZ administration enhances both hippocampal synaptic plasticity and activity of LC-NE neurons. This neural system could be the biological substrate underlying the behavioral alterations accompanying chronic DZ administration and withdrawal.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Locus Cerúleo
/
Moduladores GABAérgicos
/
Diazepam
/
Hipocampo
Limite:
Animals
Idioma:
En
Revista:
Pharmacol Biochem Behav
Ano de publicação:
2001
Tipo de documento:
Article
País de afiliação:
Argentina
País de publicação:
Estados Unidos