Interaction between noradrenaline and corticotrophin-releasing factor in the reinstatement of cocaine seeking in the rat.

Rationale: Corticotropin-releasing factor (CRF) and noradrenaline (NA) have been shown in independent studies to mediate stress-induced reinstatement of drug seeking. To date, however, a functional interaction between the systems in reinstatement has not been demonstrated.

Objectives: The objectives of this study were to determine whether CRF and NA systems can interact to influence reinstatement responding and, if so, in what direction the interaction occurs.

Effects of repeated yohimbine on the extinction and reinstatement of cocaine seeking.

Acute exposure to the pharmacological stressor yohimbine (YOH) reinstates drug seeking in rats. The present experiments investigated whether repeated exposure to YOH during extinction training affects the time-course of extinction and the magnitude of subsequent YOH- or footshock-induced reinstatement of cocaine seeking. Rats trained to self-administer cocaine were given five days of extinction training, during which they were injected with YOH (1.