Steroid anaesthesia (Althesin — CT 1341) and dorsal horn cell activities in feline spinal cord

The effects of steroid anaesthesia (Althesin — CT 1341) on dorsal horn cells (laminae 4 and 5) were studied by extracellular recordings in the spinal cat. I.v. administration of Althesin (0.2 ml/kg) strongly depressed the spontaneous and evoked activities of both types of cells. No differences were found between cells activated by noxious or innocuous stimuli. These results emphasize the fact that the transmission of afferent messages is depressed by various anaesthetics at the level of the first synapses in the CNS. The depressive effects on lamina 5 cells could explain in part the analgesic effects of Althesin.