Age-dependent changes of electrophysiologic characteristics of the stellate ganglion conducting pathways in kittens

The conducting pathways of the cat stellate ganglia were examined in newborn, 10- and 20-day-old kittens by recording the evoked responses in the branches of the ganglion following electrical stimulation of its other branches. In the course of postnatal ontogenesis, the average conduction velocity of excitation and the average amplitude of the responses was increased. In newborn and 10-day-old kittens, all fibers on their conduction velocities belong to C-fibers. In 20-day-old kittens, Aδ- and B-fibers also appeared. In this age-group, two subgroups among fibers of the C group were determined according to their conduction velocity of excitation. From 10 days of age, the axon reflex was recorded in the anastomosis and the inferior cardiac nerve following stimulation of the cranial and caudal branches of the subclavian loop. All branches of the stellate ganglia of 20-day-old kittens contain both continuous and synaptically switched fibers.