Spectral sensitivities of color receptors in the compound eye of the cockroach Periplaneta.

Abstract

AbstractIntracellular recording from single retinular cells of a white eye mutant of the cockroach Periplaneta americana stimulated between 316 and 704 nm reveals the presence of two classes of cells. In the dorsal part of the eye they are present in approximately equal numbers. Both have resting potentials of about 40 mv; neither responds with spikes.Ultraviolet receptors are maximally responsive at 365 nm (λmax); sensitivity falls steadily at longer wavelengths and is down two log units at 440 nm. The membrane responses of ultraviolet receptors usually consist of a large graded transient which can completely depolarize the cell, followed by a smaller and slower plateau of depolarization which lasts as long as the stimulus.Green receptors have λmax at about 507 nm. A tail of sensitivity extends through the violet and near ultraviolet, but sensitivity falls steadily to the long wavelength side of the λmax, and is down two log units at 615 nm. The membrane responses typically consist of a graded transient and lack the later plateau.