RESPONSES OF SINGLE DORSAL CORD CELLS TO PERIPHERAL CUTANEOUS UNMYELINATED FIBRES,
MASSACHUSETTS INST OF TECH CAMBRIDGE
Pagination or Media Count:
The fundamentally different effects of A and C stimulation on the DLC cells are emphasized. The A fibres after a short intense burst turn the cell off, which is probably the result of the negative feedback exerted by the As on themselves as seen by the negative dorsal root potential. The C fibres, on the other hand, turn the postsynaptic cell on after the repetitive discharge, which may be the effect of the positive feedback of the Cs on the As as seen by the positive dorsal root potential. It is evident from these results that both A and C fibres converge on many of the dorsal horn cutaneous cells. Furthermore, the C fibres produce a disproportionately large delayed discharge. There are prolonged inhibitory and excitatory effects after the arrival of mixed volleys. Therefore, the overall pattern will depend on the balance between the numbers of myelinated and unmyelinated fibres carrying the afferent volley.