Fig. 8.

The delayed current transient does not require close contact or extensive overlap between the axonal and dendritic domains. Top, Camera lucida drawing of a basket cell (14-d-old animal) that was filled with neurobiotin during recording and processed for histology. The short thick neurites radiating from the soma are dendrites. The axon leaves the soma on the right and takes an almost straight course, sending several collaterals along the way. It is prolonged beyond the boundary of the drawing. The Purkinje cell layer is roughly horizontal and is located at the level of the tips of the axon collaterals at the lower boundary of the cell.Middle, Composite photograph from the same cell. In the lower scale photograph the dendrites are in focus; the axon collateral that appears to overlap with the dendritic field in the drawing of thetop panel is then not in focus. Insert, Blowup of the somatodendritic region with the axon collateral in focus. The shortest distance between axonal and dendritic domains in this cell was 2 μm. Bottom, Average responses to depolarizing pulses from the same cell, with and without bicuculline, showing the presence of a normal size, delayed current transient.