Fig. 2.

Imaging of isolated activated PFs from sagittal slices. (A) Schematic 3D diagram showing the predicted effect of stimulating in the granular layer (GL). The scheme shows a block of cerebellar cortex in a sagittal slice including portions of ML and GL. The (x, y) plane is the plane of the ΔF/F image of the ML. Activated PFs crossing the horizontal (x, y) plane are expected to be vertical, and hence detected as dots in the ΔF/F image (red dots). (B) ΔF/F image from the ML of a slice where stimulation was in the adjacent GL (not in the field of view). Slice was superfused with 1 mM 4-AP. Peaks of ΔF/F arising from isolated PFs are detected above the noise level, as illustrated by the two insets showing 3D representation of ΔF/F over ROIs displayed with yellow squares. (C) Isolated ΔF/F peaks were selected to determine the averaged integrated ΔF/F signal arising from them (see Fig. 3D). Insufficiently isolated ΔF/F peaks (arrows) were ignored. (D) Schematic 3D diagram showing the effect of stimulating in the molecular layer (ML). (E) ΔF/F image from the same ML region shown in (B) but obtained for stimulation in the ML. The integrated ΔF/F signal arising from the stimulated PF beam was calculated from a large area covering the beam. (F) The beam section (see “Experimental procedure” for calculation) is shown as the red contour. (G), The ΔF/F signals were amplified by 4-AP, the effect of which was similar for ΔF/F signals evoked by ML or GL stimulation. The enhancement produced by 4-AP remained stable for at least 10 min. Black and white ΔF/F images have same contrast setting running from −0.96% to 7.40%. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)