Figure 6. Irradiance coding by “sustained” lateral geniculate neurons.

(A) Mean response of “transient” and “sustained” Opn1mw^R LGN neurons (n = 134 and 114, respectively) to 2 s blue light pulses. (B,C) Quantification of the firing rate of Opn1mw^R “sustained” (B) and “transient” (C) LGN cells during the first 500 ms (left) or remainder (500–2000 ms; right) of the light pulse. Symbols indicate mean (± SEM), and lines indicate mean (±95% CI) of the function that best described the data. Note the linear relationship between firing rate and log irradiance across the full range tested for Opn1mw^R “sustained” cells in contrast to the sigmoidal relationship saturating above 10¹² photons/cm²/s for Opn1mw^R “transient” responses.