Figure 7

Basal synaptic transmission and LTP are perturbed in TFR KO mice.

(A)Analysis of synaptic input/output (I/O) relation between the fiber volley amplitude and fEPSP amplitude, which was determined over a narrow range of stimulus intensities. Each point represents the mean of all slices tested (WT: n = 15; KO: n = 12). Representative recordings are displayed in the left, marked as WT (black) and KO (grey). Note that amplitudes of both FV and fEPSP decreased. In the right, each point of X-Y pair represents the response derived from the same stimulus intensity. (B) The comparison of paired-pulse facilitation (PPF) in WT and TFR KO mice. Two representative traces derived from WT (black) and TFR KO (KO, grey) stimulated by paired pulses with an interval of 60 ms are shown in the left. Note that the ration of fEPSP2/fEPSP1 is bigger in KO compared to WT. The right panel shows the statistics of PPF obtained at different stimulus intervals (30, 60, 90, 120,150, 180 and 210 ms) in WT (black) and KO (grey) groups. Note that PPF is generally bigger in KO group at all stimulus intervals. (C) Analysis of train stimulation waveforms reveal a smaller increase of fEPSP slope in TFR KO mice compared with WT mice. Representative traces in response to train stimuli in WT (black) and KO (grey) mice are shown in the upper panel. Analysis of charge transfer of 5 spikes is shown in the histogram below. (D) Field potential recordings were made in stratum radiatum to measure LTP induced by 100 Hz stimuli (Tet; 1 s) at t = 0 min. Sample traces from representative cells are from the numbered points indicated. Each trace is the average of three consecutive responses. (E) An LTP experiment similar to that shown in (D), except that the conditioning stimulation delivered at t = 0 min consisted of a much stronger tetanus, theta burst stimuli (TBS). Sample traces from representative cells are from the numbered points indicated. Each trace is the average of three consecutive responses.