Figure 3.

Back propagation of action potentials in a train. a, Representative examples from a range of dendritic distances from the soma illustrating dendritic responses to long (1000 ms) somatic current injections at twice rheobase, which evoked a train of APs (black traces) that backpropagated into the dendrite (red trace) with variable amplitude. Insets show enlargement of the first three to five APs. b, Dendritic amplitude of bAPs with the smallest (open circles) and the largest (filled circles) bAP amplitude in the train as function of distance from soma. c, Ratio of dendritic amplitude of smallest to biggest bAP of the train of somatic APs. d, e, Half-width (d) and latency (e) of smallest (open circles) and largest (filled circles) dendritic bAP amplitudes as a function of distance from soma. Data were fit with a single exponential where possible (dashed line, smallest bAP; solid line, biggest bAP).