abstract |
The invention is to provide an antidementic and/or antiamnesic potency enhancer that comprises an aminopiperazine or aminopiperidine derivative of a formula: <CHEM> (wherein R<1> is a lower alkyl, etc.; R<2> is hydrogen, etc.; R<3> is an aryl, etc.; A is -CO-, etc.; X is N or CH; Y is -CO-, etc.), for attaining higher antidementic and/or antiamnesic potency. |