Figure 6.

Gfa2–VIVIT improves synaptic function in Tg mice. Representative electrophysiological waveforms recorded in CA1 stratum radiatum of brain slices from WT (A1) and Tg (B1) mice in response to electrical stimulation of CA3 Schaffer collaterals. Calibration: 0.5 mV, 2.5 ms. Waveforms in each treatment group were matched to similar FV amplitudes to illustrate differences in the amplitude of the corresponding postsynaptic response. A2 and B2 show synaptic strength curves for WT (A2) and Tg (B2) mice in which mean EPSP slope (millivolts per milliseconds) amplitudes (SEM, vertical error bars) are plotted against FV (millivolts) amplitudes (SEM, horizontal error bars) across nine stimulus intensity levels. C, Mean ± SEM EPSP/FV ratios calculated from the upper two stimulus intensity levels shown in A2 and B2. The Tg Ct group exhibited a significantly reduced EPSP/FV ratio relative to both the WT Ct and Tg VIVIT groups. D, In contrast to synaptic strength, levels of PPF (mean ± SEM) did not differ across treatment group. E, The mean ± SEM EPSP slope amplitude at which a population spike appeared (i.e., population spike threshold) in the ascending phase of the field potential (see A1 and B1). The WT VIVIT and Tg Ct groups showed a reduced population spike threshold compared with WT Ct and Tg VIVIT mice. This difference reached significance for the Tg Ct group (p < 0.01 vs WT Ct).