[Gly 14 ]‐Humanin improved the learning and memory impairment induced by scopolamine in vivo

Humanin is a very recently discovered 24 amino acid linear polypeptide, which protects against cell death induced by either familial Alzheimer's disease mutant of amyloid precursor protein, presenilin‐1 or presenilin‐2 in vitro . However, it has remained uncertain whether humanin is a useful drug for the animal model of learning and memory deficit. In this study, we evaluated the effects of [Gly 14 ]‐humanin, a more potent humanin analogue, on the scopolamine HBr (1 mg kg −1 s.c.)‐induced impairment of spontaneous alternation behaviour in the Y‐maze, an index of short‐term memory in mice. [Gly 14 ]‐Humanin (1000 pmol 5 μl −1 i.c.v.) reversed the impairment without affecting the number of arm entries. These results suggest that (I) [Gly 14 ]‐humanin is a beneficial drug for the impairment of learning and memory and (II) it modulates the learning and memory function mediated via cholinergic systems in mice. British Journal of Pharmacology (2001) 134 , 1597–1599; doi: 10.1038/sj.bjp.0704429