Figure 5.

GABA iontophoresis on the axon produces somatic depolarization. A, Image of a cerebellar granule cell filled with Alexa-594. The iontophoretic pipette can be seen at the right. B, Representative depolarization recorded in the soma following GABA iontophoresis on the axon (thick bar) in control ACSF (upper trace) and in the presence of picrotoxin (lower trace). C, Images of a labeled parallel fiber and iontophoretic pipette (left) and voltage responses recorded at the soma (right) when the iontophoretic pipette is positioned adjacent to the axon (upper image/trace) or 21.6 μm from the axon (lower image/trace). Scale bar, 10 μm.