The effects of maintained light stimulation on S‐potentials recorded from the retina of a teleost fish.

Abstract

SUMMARY1. S-potential responses to transient and maintained light stimuli have been recorded from units in the mixed rod-cone retina of a teleost fish species Eugerres plumieri.2. Four spectral classes of S-potential were observed, three cone-and one rod-type. The cone-type responses were subdivided into two L-type (referred to as L1 and L2), and a C-type response. Two classes of transient depolarization response were also recorded from those retinal levels associated with the S-potential responses and these are attributed, tentatively, to rod and cone bipolar activity.3. L2-type S-potentials do not yield constant hyperpolarization during maintained light stimulation, the time course of the response potential, V, being given approximately by Vt = V0 (0.44 + 0-56 ee'4t), where Vt is the response potential at time t see following the onset of stimulation, V0 being the initial response potential.In contrast, both hyperpolarizing and depolarizing components of the C-type response were maintained under conditions of steady illumination.

Lateral interactions in the outer retina

“…Consistent evidence from a variety of species has shown that following dark adaptation, maintained photopic background (full-field) illumination hyperpolarizes horizontal cells by 30–40 mV for several minutes so that their light responses are saturated. However, if the photopic background illumination is continuously maintained, the membrane potential of horizontal cells slowly recovers in 20–30 minutes to the initial more positive dark-adapted level and the cells become light responsive again but to light stimuli of higher intensities (skate: Dowling and Ripps, 1971; fish: Ruddock and Svaetichin, 1975; Wang and Mangel, 1996; tiger salamander: Yang et al, 1999). As a result, following both prolonged light and dark adaptation, horizontal cells in mammalian and non-mammalian retinas are depolarized (approx.…”

“…As a result, following both prolonged light and dark adaptation, horizontal cells in mammalian and non-mammalian retinas are depolarized (approx. −35 mV) at rest and hyperpolarize to brief light flashes brighter than the background illumination (skate: Dowling and Ripps, 1971; fish: Ruddock and Svaetichin, 1975; Malchow and Yazulla, 1988; Wang and Mangel, 1996; tiger salamander: Yang et al, 1999; rabbit: Mangel, 1991; Ribelayga and Mangel, 2010; monkey: Zhang et al, 2011). In addition, as noted in Section 2.2, the resting membrane potential and light responsiveness of cone-driven ON- and OFF-center bipolar cells are also regulated by light/dark adaptive processes so that the cells remain light responsive from mesopic to photopic background illumination levels (Werblin, 1970; Dacey et al, 2000; Fahey and Burkhardt, 2001).…”

Spectral Responses in Zebrafish Horizontal Cells Include a Tetraphasic Response and a Novel UV-Dominated Triphasic Response

“…These responses were separated into two types based on the wavelength of maximum sensitivity (Hashimoto and Inokuchi 1981;Hashimoto et al 1988;Ruddock and Svaetichin 1975). Most (87%) were L2-types maximally stimulated by red cones, with spectral peaks slightly to the green side of the 570 nm red cone max .…”

“…Sensitivity was maximal for red and/or green light stimulation. Based on modeled spectral properties (below), monophasic cells were classified as either red-preferring L2-types (peak sensitivity Ͼ530 nm, mean 563 nm, n ϭ 86) or red/green L1-units (peak sensitivity Յ530 nm, mean 493 nm, n ϭ 13), following the classification of monophasic cells in the literature (Hashimoto and Inokuchi 1981;Hashimoto et al 1988;Ruddock and Svaetichin 1975).…”

Visual form perception

“…In contrast, horizontal cells have large summation areas and their responses provide a measure of average illumination levels over large retinal areas. It is possible that in some species, feed-back from horizontal cells compensates for changes in average illumination level (Ruddock and Svaetichin 1975). Bipolar cells, ganglion cells and neurones of the lateral geniculate body usually exhibit ' centre-surround antagonism ' in their receptive field organization.…”