Improvement in signal-to-noise ratio of each cone following coupling between foveal cones

Range ~80 %
Organism Ground squirrel Spermophilus tridecimlinatus
Reference Bloomfield SA, Völgyi B. The diverse functional roles and regulation of neuronal gap junctions in the retina. Nat Rev Neurosci. 2009 Jul10(7):495-506 doi: 10.1038/nrn2636 p.497 right column 3rd paragraphPubMed ID19491906
Primary Source [51] DeVries SH, Qi X, Smith R, Makous W, Sterling P. Electrical coupling between mammalian cones. Curr Biol. 2002 Nov 19 12(22):1900-7 DOI: 10.1016/s0960-9822(02)01261-7PubMed ID12445382
Method Primary source abstract: "In ground squirrel retina, whose triangular cone lattice resembles the human fovea, paired electrical recordings from adjacent cones demonstrated electrical coupling with an average conductance of approximately 320 pS... Psychophysical measurements employing laser interferometry to bypass the eye's optics suggest that human foveal cones experience a similar degree of neural blur and that it is invariant with light intensity. This neural blur is narrower than the eye's optical blur, and [investigators] calculate that it should improve the signal-to-noise ratio at the cone terminal by about 77%."
Comments P.497 right column 3rd paragraph: "Coupling between cones sums the correlated visual signals and attentuates the asynchronous noise. It has been calculated that the coupling between foveal cones improves the signal-to-noise ratio of each cone by nearly 80% (primary source). Overall, cone coupling improves the sensitivity and fidelity of visual signals, but at the cost of some neural blurring of the image."
Entered by Uri M
ID 117168