| Abstract: | In anesthetized cats electrical stimulation of the medial articular nerve of the knee joint evoked sympathetic reflex discharges in inferior cardiac nerves. Low intensity single stimuli elicited early reflex discharges (A-reflexes, latency 70-90 ms, duration 110-200 ms) whereas short tetanic stimulation at higher intensities evoked, in addition, late reflexes (C-reflexes, latency 390-480 ms, duration 230-400 ms). An analysis of the relation between the conduction velocity and the electrical threshold of 231 single medial articular nerve fibers revealed that the A-reflex is mainly due to activation of Group II units, whereas the C-reflex is evoked by activity in unmyelinated Group IV fibers. |
