Complex effects of general anesthesia on sensory processing in the spinal dorsal horn

A chronic animal preparation allowed us to compare activity of the same single, spinal dorsal horn neurons in the physiologically intact, awake, drug-free state and in the anesthetized state. The inhalation anesthetic enflurane produced profound, and at times, opposite effects on spinal dorsal horn neuron responses to non-noxious and noxious receptive field stimulation. Some effects would not have been predicted, based upon current understanding of anesthetics.