Fig. 4. Responses to paired pulse molecular layer stimulation. (A) Left: MG cell reconstruction to serve as a spatial reference. Right: CSD pseudocolor map with field potential traces superimposed. Arrowheads above traces indicate the times of stimulus application (Stim). (B) Calculation of the difference between the first and second responses. Color bar on the right indicates observed increase or decrease in entering current density when the first response was subtracted from the second. Dotted line indicates the spatial displacement and time course of the backpropagated event. Note that both the initial sink (associated with field potential N₂) and the later sink (associated with field potential N₃) are increased in response to the second stimulus pulse.