Figure 2: Amyloid beta inhibition of carbachol-induced hippocampal theta oscillatory activity is reversible and specific. (a) Representative recordings (left) and the corresponding power spectra (right) of hippocampal population activity recorded in the presence of carbachol 20 µM (upper trace and power spectrum) after bath application of 1 µM (middle trace and power spectrum) and after washout of Aβ (in the presence of carbachol 20 µM; lower trace and power spectrum). The graph on the right shows the quantification of the integrated spectral power from 4 to 12 Hz. Note that the -induced inhibition of theta activity is reversible upon washout. (b) Representative recordings (left) and the corresponding power spectra (right) of hippocampal population activity recorded in the presence of carbachol 20 µM (upper trace and power spectrum) after bath application of the inverse sequence of , [1 µM] (middle trace and power spectrum) and after bath application of 1 µM (in the presence of carbachol; lower trace and power spectrum). The inset shown on each power spectrum is an autocorrelogram obtained from the corresponding trace. The graph on the right shows the quantification of the integrated spectral power from 4 to 12 Hz. Note that the inverse sequence has no effect on the theta rhythm. *indicates a significant difference with respect to the carbachol-induced oscillatory activity ().