Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
EVIDENCE THAT THE MEDIAN RAPHE NUCLEUS - DORSAL HIPPOCAMPAL PATHWAY MEDIATES DIAZEPAM WITHDRAWAL INDUCED ANXIETY
Autore:
ANDREWS N; FILE SE; FERNANDES C; GONZALEZ LE; BARNES NM;
Indirizzi:
UNITED MED & DENT SCH,GUYS HOSP,PSYCHOPHARMACOL RES UNIT,DIV PHARMACOL LONDON SE1 9RT ENGLAND UNITED MED & DENT SCH,GUYS HOSP,PSYCHOPHARMACOL RES UNIT,DIV PHARMACOL LONDON SE1 9RT ENGLAND UNIV BIRMINGHAM,SCH MED,DEPT PHARMACOL BIRMINGHAM B15 2TT W MIDLANDS ENGLAND
Titolo Testata:
Psychopharmacology
fascicolo: 3, volume: 130, anno: 1997,
pagine: 228 - 234
Fonte:
ISI
Lingua:
ENG
Soggetto:
SOCIAL-INTERACTION; 5-HT RELEASE; RAT-BRAIN; 5-HYDROXYTRYPTAMINE; BUSPIRONE; AGONISTS; ONDANSETRON; DEPENDENCE; RESPONSES; BACLOFEN;
Keywords:
BENZODIAZEPINE WITHDRAWAL 5-HT RELEASE; HIPPOCAMPUS; MEDIAN RAPHE NUCLEUS; ANXIETY; IN-VIVO MICRODIALYSIS;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Science Citation Index Expanded
Science Citation Index Expanded
Citazioni:
37
Recensione:
Indirizzi per estratti:
Citazione:
N. Andrews et al., "EVIDENCE THAT THE MEDIAN RAPHE NUCLEUS - DORSAL HIPPOCAMPAL PATHWAY MEDIATES DIAZEPAM WITHDRAWAL INDUCED ANXIETY", Psychopharmacology, 130(3), 1997, pp. 228-234

Abstract

On the basis of our previous series of experiments we had postulated that the increased anxiety that occurred during diazepam withdrawal was mediated by increased 5-HT release in the hippocampus. The present series of experiments provide evidence for a major role of the median raphe nucleus (MRN) dorsal hippocampal pathway. Rats were treated once daily for 21 days with diazepam (2 mg/kg IP) and then tested after 24 h withdrawal in the social interaction test of anxiety. Relative to chronically vehicle treated animals, those withdrawn from diazepam were significantly more anxious and had significantly greater K+-evoked release of [H-3]-5-hydroxytryptamine (5-HT) from slices of dorsal and of ventral regions of the hippocampus. Estimation of extracellular concentrations of 5-HT within the dorsal hippocampus, using in-vivo microdialysis, showed doubling in the levels of 5-HT in the rats withdrawn from chronic diazepam treatment. This just failed to reach significance, but 33% of the rats showed dramatic increases (650%). It was not possible to test these animals in the social interaction test, but it is proposed that only the diazepam-withdrawn rats with raised extracellularlevels of 5-HT would have displayed increased anxiety. 5-HT1A receptor agonists injected into the MRN decrease the MRN firing rate, and hence the release of 5-HT in the dorsal hippocampus. As a further test ofour hypothesis, we examined the effects of MRN injection of the 5-HT1A receptor agonist, 8-OH DPAT, on animals withdrawn from diazepam and tested in the low light familiar condition of the social interaction test. 8-OH DPAT (50-200 ng) dose-dependently reversed the anxiogenic effect of diazepam withdrawal, while having no effects in chronic vehicle-treated animals. These results provide clear evidence that the MRN-dorsal hippocampal 5-HT pathway is at least one of the pathways playingan important role in mediating diazepam withdrawal-induced anxiety.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 25/11/20 alle ore 07:03:48