Post-training intraperitoneal administration of leu-enkephalin and beta-endorphin causes retrograde amnesia for two different tasks in rats.

[1]  D. Wied,et al.  Behavioral and electrophysiological effects of peptides related to lipotropin (beta-LPH). , 1978, The Journal of pharmacology and experimental therapeutics.

[2]  L. Stein,et al.  Brain endorphins and the sense of well-being: a psychobiological hypothesis. , 1978, Advances in biochemical psychopharmacology.