Antidromic discharges of sympathetic preganglionic neurons located outside of the spinal cord lateral horns.

Responses arising in thin ventral rootlets and antidromic discharges of single sympathetic preganglionic neurons (SPNs) in T(3) and L(2) segments of the cat spinal cord were recorded simultaneously during stimulation of the white rami communicantes in the same segments. It was shown that in addition to the classical lateral horn SPN with B-axons (conduction velocities 3-10 m/sec) there are also ventral horn SPNs which have B-axons with faster conduction velocities (10-20 m/sec) and intermediate zone SPNs with C-axons (conduction velocities 0.98-1.7 m/sec).