Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “ADAPTATION, OCULAR”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 541 records · Page 30Linked to original sources
PubMed1960

The nature of the retinal action potential, and the spectral sensitivities of ultraviolet and green receptor systems of the compound eye of the worker honey-bee.

1. The retinal action potential consists principally of a sustained negative wave which persists for as long as the stimulus. Transitory negative on-effects and off-effects may also be present, particularly at long wave lengths (green, yellow, and red) and in the light-adapted eye. 2. Only the maintained component of the potential can be elicited under CO(2) anesthesia. The transient components are reversibly eliminated from the response at about the same time as the background noise of nerve and muscle spikes. It is suggested that the sustained component arises from the receptor cells, and the other components from second and higher order neurons. 3. The compound eye does not contain a homogeneous population of receptors. A green receptor system (maximum sensitivity at about 535 mmicro) determines the response of the dark-adapted eye throughout most of the spectrum; during adaptation to yellow light, however, an ultraviolet receptor system is revealed, with maximum sensitivity at about 345 mmicro. The anatomical bases of these receptor systems are unknown; however, they include both retinula cells and neurons in the optic ganglion. 4. There is no change in spectral sensitivity (Purkinje shift) in the first three logarithmic units above the threshold of the retinal action potential. 5. The relatively great effectiveness of near ultraviolet light in stimulating the positive phototaxis of the bee does not depend on excitation of the ultraviolet receptor of the ocellus.

Action Potentials↗
PubMed1964

RAT ELECTRORETINOGRAM: EVIDENCE FOR SEPARATE PROCESSES GOVERNING B-WAVE LATENCY AND AMPLITUDE.

Studies of the simultaneous changes in the latency and amplitude of the b-wave of the rat electroretinogram (ERG) under three different conditions of adaptation show that the latency is primarily a function of the absolute stimulus intensity, being only slightly affected by conditions that strongly reduce the amplitude. This implies that the latency and the amplitude are determined by two independent processes, with the latency-process more closely linked to the initial photochemical events. Furthermore, the different adaptation conditions have surprisingly similar effects on the shape and amplitude of the electroretinogram, which suggests that they all produce only one type of variation in the amplitudedetermining process.

Acclimatization↗