The electrophysiological studies indicate that peripheral autonomic and primary sensory neurones display a wide variety of ionic currents. The experiments aimed at biophysical and pharmacological analysis of ionic currents are frequently performed on isolated neurones devoid of axones and dendrites. Consequently the ionic currents recordings are limited to the cell soma. The function of somatic ionic channels is largely unknown. We suggest that the functional meaning of the somatic ionic currents can be facilitated by analysis currents properties in functionally identified neurones. Examples are given of different biophysical and pharmacological currents properties in cardiac, glandular, cutaneous and muscular sympathetic neurones. It is concluded that the resting and reflex activity in different categories of sympathetic neurones may be profoundly affected by the biophysical properties of ionic channels expressed in their soma.