Functional role of efferents to the avian retina. I. Analysis of retinal ganglion cell receptive fields

Abstract

Receptive fields of retinal ganglion cells were analyzed during extracellular microelectrode recordings in the optic tract of the lightly anesthetized pigeon. Four major types of receptive field can be distinguished among the 359 fibers studied. Twenty-five percent of the receptive fields are relatively simple, responding at on and at off to stationary spots of light in the central region. All of the receptive fields have inhibitory surrounds of varying strength that do not produce a response when illuminated alone, but antagonize responses from the central region. Motion sensitive units comprise 15% of the recorded population; they are similar to the o n d f center type except that responses to stationary stimuli are absent or very weak while responses to moving stimuli are vigorous. Directionally selective units also have the basic features of on-off, inhibitory surround cells, but respond to moving stimuli well from the preferred direction and not at all from the null direction. Directional cells have a broad range of null directions; in about one-third of the units the range becomes broader when the stimulus involves both center and surround of the receptive field, thus enhancing directional selectivity. Directionally selective units are common, comprising 38% of the units studied. Cells unresponsive to stimuli moving from anterior in the visual field are much more common than other types, while cells unresponsive to stimuli from posterior in the field are rare. A few units (11%) respond only at on or at off to stationary stimuli in their receptive field centers; they also have antagonistic but unresponsive receptive field surrounds. The area of the visual field sampled is uniform in regard to the relative numbers of the four major receptive field types.

Responses of directional ganglion cells in the pigeon retina.

“…If the slit was moved broadside-on orthogonal to the null-preferred axis, then responses were reduced or curtailed. Comparable properties have been observed in other studies of avian directional cells (Miles, 1972;Pearlman & Hughes, 1976 Histogram C is recorded from the same cell, responding to movement through its receptive field at 5.20/sec. The chief features are vigorous discharge peaks in the preferred direction, and a period of deletions in the null sweep.…”

“…Directional ganglion cells have been reported in the pigeon retina (Maturana, 1962;Maturana & Frenk, 1963; Holden, 1969;Pearlman & Hughes, 1976). The mechanism of directional selectivity has been examined in the rabbit (Barlow & Levick, 1965).…”

Analysis of Development of Direction Selectivity in Retinotectum by a Neural Circuit Model with Spike Timing-Dependent Plasticity

“…Some types of RGCs respond selectively to the direction of motion (Cronly-Dillon, 1964;Barlow and Levick, 1965;Oyster and Barlow, 1967;Pearlman and Hughes, 1976). In the rabbit retina, direction-selective RGCs account for ϳ10% of all RGCs (Vaney, 1994;Vaney et al, 2001;Taylor and Vaney, 2003).…”

Enkephalin-containing amacrine cells in the avian retina: immunohistochemical localization.

“…Amacrine cells are located within the proximal portions of the inner nuclear layer adjacent to the inner plexiform layer and consist of at least 15 distinct morphological (18) types. This variation of amacrine cell types and their contribution to the synaptic circuitry of the inner plexiform layer presumably result in the high degree of visual information processing that is evident from physiological recordings of ganglion cell responses (26)(27)(28). Indeed, this high degree of information processing at the ganglion cell layer is the basis for classifying the avian retina as a "complex" retina (29,30).…”