P> Objective To study the different effects between the acute administration and chronic exposure of βamyloidpeptide 2535(Aβ25-35) on the Ca2+independent K+ currents in rat hippocampal and cerebral cortical neurons. Methods After different applications (acute administration and chronic exposure) of Aβ25-35 in rat hippocampal or cerebral cortical neurons, the Ca2+independent K+ currents were recorded by wholecell patch clamp technique and the cell viability was detected by Calcein-AM staining. BR> Results The amplitudes of the Ca SUP>2+/SUP>independent K+ currents were significantly decreased by acute administration to AβSUB>25-35/SUB> in acute isolation of hippocampal neurons (EM>n/EM>=11) while the amplitudes were marke