Similar levels of long-term potentiation in amyloid precursor protein-nulland wild-type mice in the CA1 region of picrotoxin treated slices

Although mutations in amyloid precursor protein (APP) are known to be invol ved in the development of Alzheimer's disease in some individuals, the role of this protein in normal brain function is poorly understood. We have rep orted previously that in APP-null mice long-term potentiation (LTP) in the CA1 region of the hippocampus is present but its magnitude is reduced compa red to wild-type littermate controls. in the present study, we have confirm ed this deficit using a different theta burst induction protocol. Significa ntly, however, we find that this deficit is no longer apparent when LTP exp eriments are performed following blockade of gamma-aminobutyric acid(A) rec eptors. These results suggest that the LTP process per se is not altered by the absence of APP. The deficit may therefore be an indirect consequence o f other changes in the hippocampus that occur in the APP-null animal. (C) 2 000 Elsevier Science Ireland Ltd. All rights reserved.