Fig. 2

Extraction of the firing phase shift for each spike during a single run through the field of a CA3 place cell on the linear track. a Each firing of cell 3 as a single vertical line during the 1 s of data. b Phase of each spike relative to the theta cycle within which it falls as a horizontal line. c Hippocampal theta activity recorded at the same time as the single unit. d Result of the theta template matching algorithm. Note that the amplitude and the time between onsets of each template match varies to fit the variations in the theta. The small vertical ticks above the electroencephalogram (EEG) and below the template fits mark the beginning of each theta cycle. The cell clearly fires six bursts of spikes during this run through the place field. Comparison of each burst with the concomitant theta wave shows that each successive burst fires on an earlier part of the theta. This is shown clearly by the descending staircase of the phase correlates in B. EEG voltage in C is + 1 to - 1 mV. Total time between marks on the x axis is 1 s. Reproduced from [50]