Figure 2.

Creation of spike patterns in vitro. A, A prefrontal pyramidal neuron was somatically injected with a sine wave current waveform (bottom trace). The frequency was twice the preferred frequency of the cell for this sine wave amplitude and DC level (Fellous et al., 2001). After a transient, the cell spiked once every two cycles, either on the even (top) or odd (middle) cycles. The overall reliability of the cell was 0.49. B, Rastergram showing 100 trials for the same cell as in A. C, Same rastergram as in A, with trials reordered according to whether the cell settled on the even or odd cycles. Two separate reliable sets of trials are apparent for the even (reliability, 0.89) and odd (reliability, 0.92) cycles. The dashed line separates the two sets. Dots indicate spike times that are common to the two sets.