curve (fiber volley against fEPSP slope). There was no difference in input/output ratio of APP+/− vs. APP−/− at either age group (Fig. 4C, D). Thus the reduction in LTP was not mirrored by changes in basal synaptic transmission. Finally, paired-pulse facilitation was similar between APP−/− and control mice in both age groups (Fig. 4E, F) indicating no presynaptic impairment in the hippocampus of APP−/− mice.
