Figure 2.

Response of synaptic AMPARs to large-spot illumination at various light intensities. A, Averaged (4 traces) large-spot pEPSCs in response to increasing UV illumination. The intensity of a 0.1 ms pulse was increased to its maximum, after which the duration was increased to 0.2, 0.5, and 1.0 ms. B, Relationship between the relative peak amplitude of pEPSCs and normalized integral of light (n = 20). Dashed line denotes 90% criteria for achieving a saturating response. C, Histogram of maximum peak currents of saturated responses for 20 cells. Thick black line denotes the mean maximal amplitude of the pEPSC of all cells, and the dashed black line indicates the population average maximal synaptic output [mean number of release sites multiplied by average quantal current, N × Q (taken from Sargent et al., 2005)]. Data have been corrected for series resistance voltage errors.