Fig. 7.

Spearman rank order correlation between the SSE and the input density. (A) Data from recording from sagittal (gray; n = 41) and transverse (black; n = 25) slices are superimposed to extend the variabilty of SEE amplitude (determined from the change in ΔF/F at +8 s). (B) The SSE does not correlate significantly with the beam section diameter, which varied between experiments due to variations in the stimulation intensity. This shows that the SSE does not depend on the strength of the stimulation in the range explored. (C) The SSE plotted against the fEPSP amplitude exhibits a trend for a negative correlation, which does not reach statistical significance (p = 0.07). (D) The SSE showed a significant correlation with the input density index (FV amplitude divided by the beam section; in μV μm⁻²). The input density unit was converted in number of PFs per surface unit of ML in the sagittal plane (μm⁻²). An exponential regression of the data (passing through the origin since no SSE is detected for the very low input densities obtained with GL stimulation) is shown (dotted line).