[Convergence of preganglionic fibers on the vasomotor neurons of the sympathetic ganglia of cats].

By means of intracellular recordings from the neurons of isolated lumbar ganglia III-IV it is shown that B1-, B2- and C-preganglionic fibres widely converge on these neurons. The neurons antidromically activated by stimulation of muscular and cutaneous branches were identified as vasomotor ones. The latter had distinct features of preganglionic fibre convergence. Only B2- and C-preganglionic fibres were able to activate them, but the efficacy of the B2-fibres excitatory action was considerably higher. The vasomotor neurons had a lower conduction velocity in its axons (0.95 +/- 0.05 m/s) as compared to other postganglionic neurons (1.30 +/- 0.15 m/s).