Volume 38 #1

Contents

1. Рroblems of diagnostics of dysfunctions of the olfactory analyzer of laboratory animals on the basis of behavioral and electrophysiological methods of research
2. Changes in the visual areas of the cerebral cortex in children with left-sided anisometropic amblyopia according to structural MRI and resting-state fMRI
3. In search of the molecular mechanisms of adaptation memory in rods: basic activity of phosphodiesterase
4. Non-invasive recording of electroretinogram from both compound eyes in the cockroach Periplaneta americana L. in response to light stimuli
5. Individual and typological features of motor memory in problems of control of ergacy systems in the absence of visual feedback
6. Discrimination of rippled spectra with various ripple widths in listeners with normal and impaired hearing

Retinal rods, the photoreceptors responsible for twilight vision, are capable of adapting to a wide range of light levels. The molecular mechanisms of light adaptation have been well studied, but an interesting question is what changes occur in the phototransduction cascade after the adaptive light stimuli are eliminated. Previously, we showed the phenomenon of adaptation memory in amphibian rods: after background illumination photoreceptor sensitivity to light remained reduced for several minutes, while the dark current recovered within 20—30 s. This suggests the existence of additional, as yet unknown, regulatory mechanisms of the phototransduction cascade that act after the adaptive effect of light. In search of specific mechanisms that could explain the effect of adaptation memory, we performed electrophysiological experiments on isolated frog rods to evaluate the basal activity of the effector enzyme of the phototransduction cascade, the phosphodiesterase type 6, in the dark and after saturating background illumination. It was found that the post-adaptation state of rods was characterized by increased basal phosphodiesterase activity, which gradually decreased to the dark level within tens of seconds after turning off the adaptive illumination. These results also suggest that the components of the phototransduction cascade may undergo some unstudied changes after light adaptation.

Key words: phototransduction cascade, rods, adaptation memory, phosphodiesterase

DOI: 10.31857/S0235009224010032

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