The involvement of an opiate mechanism in the sensitizated behavioral deficit induced by early chronic variable stress: Influence of desipramine.

ZURITA, A., CUADRA, G. AND MOLINA, V.

BEHAVIOURAL BRAIN RESEARCH

Elsevier

Lugar: Netherlands; Año: 1999 vol. 100 p. 153 - 153

0166-4328

span lang="en" style="FONT-SIZE: 10pt; FONT-FAMILY: Arial; mso-ansi-language: EN-US; mso-fareast-font-family: "Times New Roman"; mso-fareast-language: ES-MX; mso-bidi-language: AR-SA">The influence of early chronic variable stress (CVS) associated with persistent desipramine (DMI) administration was examined on escape performance. Animals were exposed to CVS and 1 day later administered DMI (5 mg/kg, i.p. twice a day) or vehicle (VH) during six consecutive days. Escape performance was assessed over 24 h following inescapable shock (IS) exposure. Higher escape failures were observed in CVS shocked rats compared with unstressed shocked animals. DMI normalized escape failures in both groups. In order to investigate the role of an endogenous opiate mechanism presumably activated by CVS exposure in this behavioral deficit, rats were administered naltrexone (NAL, 2 mg/kg i.p.) or VH prior to each daily stressor of the CVS regime. NAL pretreatment blocked escape failures performed