Figure 2.
Stability of topographic maps over time in the anesthetized animal. A, D, G, First-frame-subtracted raw images to D3 indentation stimulation, aligned across three different imaging sessions. For each image, the clipping range is ∼0.2%. Each image was clipped individually to ± 2 SDs from its mean gray level. For the three imaging sessions in A, D, and G, signals were averaged from 45 (n = 9 blocks), 60 (n = 12 blocks), and 40 (n = 8 blocks) trials, respectively. B, E, H, Color outlines derived from filtering and the thresholding method were overlaid on the raw images to indicate the location of greatest response. C, F, I, Corresponding blood vessel images from each day. J, Locations of activation indicated by color outlines were superimposed on the blood vessel map. The inset illustrates an expanded image of activation outlines and electrode penetration (green dot). The dashed line indicates the border between are as 3b and 1. K, Absolute peak amplitudes of optical signal derived from three imaging sessions. L, Lateral; P, posterior. Scale bar, 1 mm.