Dose Response Curves of Althesin on Spontaneous Single Unit Activity of Various Dorsal Horn Rexed Laminae

Dose response curves of Althesin on single unit activities of various dorsal horn Rexed laminae were studied using an extracellular microelectrode recording technique in decerebrated spinal cats. Althesin 33,50,100 and 200μl/kg I. V. suppressed in a dose related manner spontaneous single unit activity in Rexed lamina 5,known to respond principally to noxious stimuli. Althesin 100μl/kg and 200μl/kg depressed in a dose related manner spontaneous single unit activity in a lamina 4 and lamina 6,but a small dose of Althesin 33μl/kg and 50μl/kg I. V. did not suppress lamina 4 and lamina 6,with proprioceptive input, rather these units were adversely facilitated.