Figure 1.

Properties of VSD imaging recordings. (a) Top. Time course of the peak amplitude of VSD signals averaged over five experiments in which TBS was not delivered. The signals tended to decrease exponentially in the first minutes of the acquisition to reach a steady-state level. The fitting function is represented over the experimental data, while dashed lines represent the fitting functions obtained by using the maximum deviations of the experimental data. Bottom. Time course of five regions of interest taken from a single experiment showing persistent positive or negative variations following TBS. Note that the control period used to calculate changes in VSD peak amplitude was taken in the steady-state region. (b) Top. VSD signal taken from granular layer and obtained in response to a single stimulus delivered to the mf. The trace was sampled at 2 kHz without averaging or filtering. The inset shows the initial phase of the VSD response (scale bar 10 ms and 0.1 ΔF/F ₀). Bottom. The trace shows the average of 10 repetitions sampled at 1 kHZ. (c) Top. VSD signals obtained in control solution (black trace) and in response to the application of D-APV (dark gray) and NBQX (light gray). Bottom. VSD signals obtained in control solution (black) and in the presence of 10 µM gabazine.