Figure 2.

Model with spatially offset but nonprecessing input components. A, Traces are the relative strengths of the driving inputs from CA3 (dashed gray line) and EC3 (solid black line) as a function of time as the animal moves along the track length at 40 cm/s. Dotted boxes indicate regions of time that are expanded in B, C, and D. B, Spikes are synaptic inputs from CA3 (gray) and EC3 (black) resulting from one example run along the track in the preferred direction across the region indicated by the leftmost box in A. Note that the time axis is much expanded compared with that in A. The dotted trace is the theta oscillation. C, Same as B but for region indicated by center box in A. D, Same as B but for region indicated by rightmost box in A. B–D, the amplitudes (α₁, α₂) of the two input components are significantly decreased (this allowed individual synaptic inputs to be discernible) compared with other parts. E, Spike raster of the CA1 model cell when driven only by input from CA3. Each dot is the theta phase of an action potential plotted as a function of animal position at the time the action potential was fired. F, Spike raster of the model CA1 cell when driven only by input from EC3. G, Spike raster of the model CA1 cell when driven by both the CA3 and EC3 input components. The same data are plotted across two theta cycles for clarity. The solid line is the predicted spike phase plotted as a function of position. For clarity, the predicted phase is plotted over only one theta cycle. E–G, spike times were collected over 200 runs along the track in the preferred direction.