Long latency spinal cord dorsum potential; suppression by intrathecal morphine and enkephalin analog

Short Communication: Long‐lasting Depolarization of the Central Terminals of Cutaneous Afferents in L7 Segment Evoked by Volleys Ascending From the Sacral Cord in the Cat

“…The long-lasting PAD seen in our experiments differs from that observed after administration of DOPA ( A n d h et al. 1964, 1966) and also from PAD evoked by ascending volleys in the rat lumbar cord (Peets et a/. 1984).…”

“…1964, 1966) and also from PAD evoked by ascending volleys in the rat lumbar cord (Peets et a/. 1984).…”

Spinal facilitation of descending motor input

“…At higher intensities of stimulation, it has been reported the appearance of both, a small negative N3 wave superimposed on the large positive P wave, which might originate from the activation of group III fibers (Bozdoğan and Alpsan, 1987), and of a slower late component (LC) with a latency in the range of 200 ms, which has been ascribed to electrical stimulation of C-fibers in the tail (Peets et al, 1984).…”

“…Classical electrophysiology approaches can trace the arrival of incoming sensory input to the cord, by dissecting out each different peak composing focal potentials elicited by electrical stimulation and recorded from the surface of the spinal cord. Although the exact profile of focal potentials derived from the cord surface depends on multiple factors, such as recording site, stimulated structures and pulse strength, they always appear as an initial positive spike followed by negative waves reflecting the mono-and polysynaptic activation of spinal neurons followed by a large and long duration positive potential generated by the depolarization of primary afferents (Brooks and Eccles, 1947;Bernhard, 1952Bernhard, , 1953Eccles et al, 1954;Coombs et al, 1956;Peets et al, 1984;Bozdoğan and Alpsan, 1987;Edgley and Jankowska, 1987;Harrison et al, 1988;Koerber et al, 1990Koerber et al, , 1991Jankowska and Riddell, 1993;Wall and Lidierth, 1997;Riddell and Hadian, 1998;Quiroz-González et al, 2011Van Soens et al, 2015). When focal potentials are evoked by electrical pulses applied to peripheral nerves and are recorded from the dorsal horns, they are named cord dorsum potentials (CDPs).…”