Neuronal Currents (s) having Simultaneous whole-cell recordings, made from the soma and dendrites rat brain slices, showed that AP evoked by either current pulses or synaptic stimulation of parallel or climbing fibers, always occurred first at the soma and decreased in amplitude with increasing distance into the dendrites. Simultaneous somatic and axonal recordings showed that these action potentials were initiated in the axon. Outside-out patches excised from the soma and dendrites up to about 100um revealed a channel density decreasing with distance from the soma. as Publication facts