Figure 5. Lack of APP does not affect the theta phase of maximal gamma amplitude.

The line plots show the mean (fast) gamma amplitude as a function of theta phase for control (green) and APP-KO (blue) mice; the results were obtained from the same data as in Figs 1, 2, 3, 4, as labeled (hippocampal recordings correspond to stratum radiatum below the reversal of theta phase). The amplitude was normalized within animals such that the sum of its values across a theta cycle is 1. The bar graphs show the mean theta phase of maximal amplitude in each case; error bars denote ± angular SD. Notice reduced variations of (fast) gamma amplitude within theta cycles in the parietal cortex and hippocampus of APP-KO animals, but not in prefrontal cortex. The theta phase of maximal amplitude is not different between genotypes.