Abstract
The effects of 746 CE on the EEG in the unanesthetized rabbits and in the curarized cats were studied.
Rabbits: 1) Following administration of 2 to 4 mg/kg of 746 CE (i. v.), a high voltage slow wave in the neocortex and an irregular slow wave activity in the hippocampus were developed for about 30 minutes. These characteristic changes in EEG produced by 746 CE were not affected by an intravenous injection of 1 mg/kg of levallorphan. 2) The threshold voltages for the EEG arousal responses induced by a high rate stimulation (100 cps, 1 msec.) of the midbrain reticular formation, and of N. centralis medialis were increased to 5- to 9-fold and 1.5- to 2-fold respectively by 4 mg/kg (i. v.). By the high rate stimulation of the posterior hypothalamic area, they were increased to 1.5- to 2-fold in the neocortex, and 1.2- to 1.5-fold in the hippocampus respectively by 4 mg/kg (i. v.). 3) The recruiting responses induced by a low rate stimulation (10 cps, 1 msec.) of N. centralis medialis, and of N. anteroventralis were not influenced by 4 mg/kg (i. v.). 4) The augmenting response induced by the low rate stimulation of the ventralisposterolateralis of the thalamus was not influenced by 4 mg/kg (i. v.). 5) The induced spindle burst by a single stimulus of N. caudatus was reduced by 4 mg/kg (i. v.). 6) The hippocampal afterdischarges were shortened in duration and increased in the threshold voltage by 4 mg/kg (i. v.).
Cats: 1) A slow wave activity in the EEG accompanied by a rise in blood pressure was produced in cats with the ligated basilar artery at the midpontine level by the intracarotid injection of 0.2 to 1 mg/kg. On the other hand, using the same preparations, low voltage fast waves in the neocortex and an increase in the frequency of the phrenic volley accompanied by a rise in blood pressure were produced by the intravertebral injection of 0.1 to 0.2 mg/kg.
