The Drosophila gene amn (amnesiac) was previously shown to be homologous to the mammalian gene encoding PACAP (Adcyap1) and amn Drosophila mutants show memory impairments similar to rodent PACAP/PAC1R mutants (Feany and Quinn, 1995). The gene discussed is ADCYAP1R1; the disease is memory impairment.