The effect of the microinjection of Xenopus oocytes with various cRNAs coding for Presenilin 1 and four mutated presenilins linked to early onset familial forms of Alzheimer's disease was examined. These cRNAs were injected either alone or in combination with the cRNA encoding betaAPP751 and the Swedish mutated form of betaAPP751 known to produce exacerbated amount of Abeta. Current-voltage relationships generated by voltage step were recorded. None of the cRNA injected alone or in combination displayed the ability to modify the current recorded with naive cells. Altogether, this study shows that Presenilin 1 does not mediate membrane currents and is more likely involved in the physiopathological maturation of betaAPP.