Common noise in the firing of neighbouring ganglion cells in goldfish retina.

Abstract

SUMMARY1. Pairs of goldfish retinal ganglion cells with overlapping receptive fields were recorded during stimulation with repeated light flashes. Cross-correlation histograms for 'maintained' discharge, 'on' responses, and 'off' responses were computed with a correction for the systematic responses to the stimuli; cross-covariances were derived from these. If stimulus-induced signals and noise combine linearly, then the cross-covariances are independent of differences in mean firing rate.2. Cross-covariances of pairs of cells with the same response polarity displayed a positive peak near zero lag; pairs with complementary responses showed a negative peak. 'On-off' cells could generally be classified as on-like or off-like, based on the plateau of firing during a prolonged flash and the relative magnitudes of the on and off peak responses; the cross-covariances of these cells were as one would predict if they were pure on-or off-centre neurones.3. The cross-covariances derived from the on period usually differed in magnitude from those derived in the dark (either maintained or off response). In general, cross-covariances for off responses were nearly identical to those for the maintained discharges ofthe same pair, although the mean rates at off were usually quite different from the maintained. The change in magnitude of the cross-covariances from on responses therefore appears to be a non-linear effect of light, and not of the changes in firing rate induced by the light.4. Other features of the cross-covariances were not affected by stimulation. The general shapes remained fairly constant, and the lags at which the peaks occurred were not consistently affected.5. We estimated the variance of the firing rate of each unit in three ways, and used two methods of portioning the variance implied by the cross-covariances; from these estimates, we obtained an upper bound for the proportion of the variance of firing of a cell which is due to the common noise that affects both members of a pair. We found that the common influence accounts for less than 20 % of the total variance.During stimulation, both the magnitude of the cross-covariance and the variance of the rates change; however, the percentage of total variance contributed by the common noise source is constant.

Activity sharpens the regenerating retinotectal projection in goldfish: Sensitive period for strobe illumination and lack of effect on synaptogenesis and on ganglion cell receptive field properties

“…The results are consistent with a proposed model based upon a stabilization of retinotopically appropriate synapses via correlated activity of neighboring ganglion cells (Arnett, 1978;Ginsberg et al, 1984;Willshaw and von der Malsburg, 1976) and the summation of postsynaptic responses. Under normal visual conditions neighboring ganglion cells of the same type should fire with a high degree of correlation, since their receptive fields overlap to a great degree.…”

Models for the cross-correlation between retinal ganglion cells

“…A general in-phase or out-of-phase change in mean ®ring rate as two cells respond to the same visual stimuli can be attributed to the overlap of their receptive ®elds. A less obvious eect is the short-term cross-correlation between impulse times that is evident both during responses and in maintained discharges (Arnett 1978;Arnett and Spraker 1981;Ginsburg et al 1984;Johnsen and Levine 1983;Mastronarde 1983aMastronarde ,b, 1989Meister et al 1995;Meister 1996;Rodieck 1967). When both ganglion cells in a pair exhibit the same polarity of responses to lights in the centers of their receptive ®elds (i.e.…”

The potential coding utility of intercell cross-correlations in the retina

“…The data reported here, analyzed differently in a previous study (Levine et al 2002), were collected following standard methods used in our lab (Ginsburg et al 1984); these methods are in compliance with procedures approved by the UIC Animal Care Committee. Briefly, goldfish (Carassius auratus) were pithed and the retina removed from a hemisected eye.…”

“…The retina, resting on its pad of vitreous humor, was maintained in moist oxygen on a glass plate through which stimuli were projected. A single platinum-iridium microelectrode recorded the activity of two ganglion cells; dedicated electronic logic circuitry segregated the signal into two separate impulse trains (Ginsburg et al 1984). Impulse times were recorded to the nearest millisecond.…”

“…Neighboring cells of similar response polarity with overlapping receptive fields tend to fire in synchrony, with a significantly greater fraction of the impulses in each train occurring in close temporal proximity to those in the other train than would be expected by chance if the two trains were independent. Conversely, pairs with opposite polarity tend to avoid firing in synchrony (Arnett 1978;Arnett Spraker 1981;Mastronarde 1983, Ginsburg et al 1984. Considerable effort has been expended to understand the mechanism by which this cross-correlation is effected (Johnsen and Levine 1983;Mastronarde 1983;Ginsburg et al 1984;Levine 1997Levine , 1998Brivanlou et al 1998).…”