Figure 4.

Bhc-glu requires about five times less UV intensity than does CNB-glu to generate similar currents in pyramidal neurons from layers II/III of rat visual cortex. (A) Evoked current responses from uncaging 50 μM Bhc-glu at 2, 3, and 4 mW and 50 μM CNB-glu at increasing light intensities of 10, 16, and 21 mW. The horizontal bars above the traces indicate the 10 ms-long UV photolysis, 20 ms after the beginning of trace. Vertical scale, 50 pA. Horizontal scale, 50 ms. (B) Mean normalized current amplitudes (±SEM) from uncaging Bhc-glu (□, n = 4 cells) or CNB-glu (○, n = 4 cells) are plotted as a function of varying light intensities delivered to the slice, on a log scale. The numbers of cells tested at each light intensity are indicated by the numbers inside the symbols. To reduce intercell variation in response sizes, amplitudes for each cell were normalized to the average maximum response at the light intensity giving the maximal response for that cell.