Fig. 3. Method for estimating `length constant' of apical dendrites. (A) CSD in a gray-scale map for data obtained with molecular layer stimulation. A typical Source/Sink/Source spatial pattern can be observed (distal towards top). (B) Spatial distribution of current density profile at time indicated by dotted line in A, corresponding to the peak of the synaptic sink (distal towards top). Inset in B shows the exponential function fitted to the distal tail of the synaptic source.