Stria terminalis lesions attenuate the effects of posttraining naloxone and beta-endorphin on retention.
These experiments examined the effect of posttraining administration of naloxone and beta-endorphin in rats with lesions of the stria terminalis (ST). Rats with sham or bilateral ST lesions were trained either in an inhibitory avoidance task or in a Y-maze discrimination task and, immediately after training, received an ip injection of saline, naloxone (0.5, 2.0 or 5.0 mg/kg in the avoidance task; 3.0 mg/kg in the Y-maze task), or beta-endorphin (10.0 micrograms/kg). Retention of each task was tested 24 hr following training. In the Y-maze task, retention was assessed by training on a reversed discrimination. The ST lesions did not affect retention of either task in otherwise untreated animals. However, in both tasks, ST lesions attenuated the memory-enhancing effects of naloxone as well as the memory-impairing effects of beta-endorphin. These findings are consistent with other recent evidence suggesting that the amygdala may be involved in posttraining memory modulation.
D000679:Amygdala / Q000502:physiology*; D000818:Animals; D001362:Avoidance Learning / Q000502:physiology; D001931:Brain Mapping; D004193:Discrimination Learning / Q000502:physiology; D004723:Endorphins / Q000494:pharmacology*; D008297:Male; D008568:Memory / Q000502:physiology*; D009270:Naloxone / Q000494:pharmacology*; D009434:Neural Pathways / Q000502:physiology; D051381:Rats; D011919:Rats, Inbred Strains; D012153:Retention, Psychology / Q000187:drug effects / Q000502:physiology*; D001615:beta-Endorphin
D004723:Endorphins; D009270:Naloxone; D001615:beta-Endorphin