Red nucleus fast activity and signs of paradoxical sleep appearing during the extinction of experimental seizures

Abstract

The electrical activity of several cortical and subcortical structures was analyzed in cats during electrically and pentamethylenetetrazol-induced seizures. These activities were compared with the spinal monosynaptic reflex variations during the same seizures. The following results are described: 1. 1. The monosynaptic spinal reflex is initially facilitated during the tonic phase and when it is elicited in the vicinity of a clonic wave. 2. 2. In the last stages of the seizure, the monosynaptic spinal reflex appears deeply inhibited. This inhibition coincides with the appearance of fast sinusoidal (15-40 c/sec) activity in the red nucleus. Often this activity exceeds the abrupt cortical end of the seizure. 3. 3. The electrical stimulation of red nucleus areas which show fast sinusoidal activity is also associated with a spinal monosynaptic reflex depression. 4. 4. The electrical stimulation of the cortical sensori-motor areas in which the tonic-clonic activity was recorded facilitates the monosynaptic spinal reflex. 5. 5. In the last stages of the convulsive activity, central and peripheral signs appear which are similar to those described for paradoxical or REM phase of normal sleep. © 1971.