Abstract:

Intracellular responses of dorsal column postsynaptic neurons to electrical stimulation of isolated cervical dorsal column and cutaneous receptive field were recorded with microelectrede from the dorsal horn of the lumbosacral spinal cord in anesthetized and immobilized cats. In addition to antidromic, orthodromic, and spontaneaus potentials regularly recorded,synaPtid potentials were also registered.No distinct prepotentials and A-B in flection were seen in the antidromic potentials. Each orthodromic, spontaneous, and synaPtic potential consisted of a prepotential, a spike, and a afterpotential and showed A and B components on the rising phase of their spike. Postsynaptic potentials manifested current effect and frequency dependency and their IPSP displayed a prolonged inhibition.The results indicate that dorsal column postsynaptic neurons possess a relatively simplified geometric organization and a considerable complexity in their local synaptic circuitry.