Figure 2

Confirmation of the elasticity results of Eytan et al. (2003) [34]. One electrode was initially stimulated at 1 Hz for one hour (solid symbols), while another was stimulated at 1/60 Hz (open symbols). Then, the roles were reversed. The graph shows the number of spikes recorded array-wide, 15–30 ms after a stimulus, normalized to the value at the beginning of the experiment. 'Start' refers to the first stimulus to the 'slow' electrode, or the average of the first 5 stimuli to the 'fast' electrode; 'Early' refers to the average of the first 5 stimuli to the 'slow' electrode, or the average of the 5 × 4 surrounding stimuli to the 'fast' electrode; 'Late' refers to average of the last 20 stimuli to the 'slow' electrode, or the average of the last 1200 stimuli to the 'fast' electrode. (This slightly unusual way of organizing the data was used to balance the need to collect sufficient statistics with the desire to measure as close as possible to the beginning of the experiment.) Data are mean ± SEM (in log-space) from 16 experiments on 4 cultures. The sequence of open and closed symbols near the top of the graph are a cartoon of the stimulation sequence; the actual number of stimuli was much greater.