RESUMEN
One of the purposes of this study was to examine whether b-wave measurements can be used in the evaluation of scotopic spectral sensitivity in Prussian carp measurements when the eyes were surgically deprived of cornea, lens, and most of the vitreous. Another goal was testing the new fitting procedure for A2-based photopigments. Using fitted amplitude-log intensity functions for threshold calculation, and two models for computer-assisted fitting of spectral sensitivity curves, no significant differences in λ(max) were found between rod photopigments and b-wave-based spectral sensitivity.
Asunto(s)
Carpas/fisiología , Adaptación a la Oscuridad/fisiología , Retina/fisiología , Animales , Electrorretinografía/veterinariaRESUMEN
Comparative electroretinographic studies of the d-wave evoked with long duration photo stimuli in dark- and light-adapted fish species (three marine and three freshwater) were performed. At the end of prolonged photo-stimulation in scotopic conditions a negative d-wave appears in electroretinograms of dogfish shark, eel and goldfish diminishing and eventually changing with intensity of photo-stimulation, while in rudd it only increases. Dark-adapted electroretinograms of two percids (perch and painted comber) exhibit a positive d-wave that approaches the b-wave amplitude under bright photopic conditions. Judging from the d-wave, only the rod pathway is active in dark-adapted dogfish shark, eel, and goldfish. Under the light adaptation, cone pathways are active in eel and goldfish, whereas the positive response to the end of light stimuli in dogfish shark could be explained by independent ON and OFF pathways from outer to inner retina via bipolar cells. In the case of two percids, dark adaptation has no influence on cone pathways. The d-wave of rudd behaves like cone-driven d-waves but in opposite sign. The data thus show that the d-wave form, amplitude and sign depend on interconnection of ON and OFF pathways as determined by the state of adaptation and/or type of photoreceptor.
