Rapid photopigment conversions in blowfly visual sense cells consequences for receptor potential and pupillary response.

Combined optical and electrophysiological experiments on the kinetics of visual pigment conversions in blowfly and the resulting pupillary response and late receptor potential are described. The photometrically detectable conversions of rhodopsin and metarhodopsin in the living wild type fly are completed within 0.5 ms. Prolonged pupillary responses and receptor potentials occur upon intense blue flashes. Subsequent intense red flashes abolish the prolonged responses in the case of both membrane potential and the pupil. The interrelation of potential and pupil is discussed.