Temporal Dynamics of Distinct CA1 Cell Populations during Unconscious State Induced by Ketamine
(A) Histological confirmation of the electrodes position. The top panel shows the atlas of the mouse brain, the brown bars illustrate the position of electrode arrays with the tips in the pyramidal cell layer. The lower panel shows Nissl staining in a hippocampal slice; the small holes indicating the actual position of the electrode bundle marked by a small amount of current. (B) The characteristic oscillations also confirm the recording happened in the hippocampal CA1 region. The top panel shows an example of LFP recorded from one channel during SWS, and the filtered LFP shows high-frequency ripple (100–250 Hz). The middle and lower panels show the LFP recorded when the animal was in REM and running, and LFP_theta indicates the characteristic theta oscillations (4–12 Hz). Vertical scale bar represents 500 mV for LFP, horizontal scale bar represents 0.1 sec time. (C, D) Stable recordings were confirmed as judged by the waveforms of recorded cells at the beginning (left subpanel), during (middle), and end (right) of the experiments. One representative putative pyramidal cell (C) and one representative putative interneuron (D) are shown here. The waveforms were plotted from a 100-sec recording in the beginning (upper row) and end (lower row) of recordings.