Waveforms of LPP fEPSPs are comparable in early and later adulthood. A, B, Responses from individual slices were normalized to their peak amplitude and then averaged across all slices within a group. At left, mean ± SEM traces for the different age groups were superimposed for mouse (3-month-old, N = 8; 6-month-old, N = 9; 10-month-old, N = 7; A) and rat (3-month-old, N = 7; 8-month-old, N = 7; B); there were no obvious differences between 3-month-old and older rodents. Calibration: (in B) A, B, 50% peak fEPSP amplitude, 10 ms. At right, graphs show the initial slopes, and decay time constants (tau) did not differ between young and older mice (A; slope: p = 0.431; decay tau: p = 0.999, one-way ANOVA; 3-month-old, N = 7; 6-month-old, N = 8; 10-month-old, N = 7) and rats (B; slope: p = 0.159, t test; decay tau: p = 0.5406; 3-month-old, N = 7; 8-month-old, N = 7). C, D, Input/output (fiber volley vs fEPSP amplitude) curves were comparable across ages in mice (C; 3-month-old, N = 5; 6-month-old, N = 6, 10-month-old, N = 5) and rats (D; 3-month-old, N = 7; 8-month-old, N = 8); traces for the different age groups are shown at right. Calibration: (in D) C, D, 1 mV, 10 ms.