Temporal Dynamics of Distinct CA1 Cell Populations during Unconscious State Induced by Ketamine
(A) Spike rasters of the putative O-LM cell (red) and simultaneously recorded pyramidal cells (blue) after ketamine injection, during running and slow-wave sleep are shown (left subpanels). The cross-correlation functions of the interneuron and pyramidal cell joint-activities are plotted on the right. The black line is the cross-correlation during the awake rest state. This unit has negative correlation with pyramidal cells at time 0 in the cross-correlation plot (upper right panel). (B) The basic properties of this O-LM cell. The most upper left panel shows the average spike waveforms. The middle left panel illustrates that this unit has strongly tendency to fire in the valleys of theta oscillations (p<0.001, Rayleigth's test). The lower left panel shows the firing rate is significantly decreased during ripple epochs. (C) Autocorrelograms in different states: after ketamine injection, during running, and during sleep respectively. Autocorrelograms are shown in two time scales: 0–200 ms and 0–1.5 sec.