抄録
1. The relation between the change in surface negative cortical response of the rabbit during Nembutal anesthesia and the activity of individual neurons in the cortex was studied intracellulary or extracellulary with surface electrode and microelectrode. With Nembutal anesthesia the response increased in amplitude, and the form changed from monophasic to biphasic.
2. At the depth of 0.4mm from the surface spiky response composed of many units was evoked by surface stimulation. The number of unit spikes did not change or slightly decreased, even when the animal was anesthetized with Nembutal.
3. Among the spontaneously firing units there was a sort of neuron having intimate relation to EEG.
4. Spontaneously firing units were depressed for 50-300 msec by surface stimulation, the depressed period varied with the strength of stimulus at the surface. This depression was due to IPSP. With Nembutal anesthesia the duration of the period did not show any change.
5. The firing level of neurons in the cortex remained constant during Nembutal anesthesia, but deteriorated neurons showed the shift of firing level. The deteriorated neuron responded to direct transmembrane stimulating current passing through microelectrode with graded response, sometimes with oscillation of membrane potential.
6. The relation between the potential change at a point along dendrite neces sary to fire the cell and the distance from the initial segment was mathe matically derived. And the possibility, that the synapses near to the initial segment might be block with Nembutal anesthesia, was shown.
