Pp. Zak et al., Ionochromic properties of long-wave-sensitive cones in the goldfish retina: an electrophysiological and microspectrophotometric study, VISION RES, 41(14), 2001, pp. 1755-1763
Long-wave-sensitive (LWS) cone visual pigments are sensitive to the concent
ration of chloride ions and show a spectral shift to shorter wavelengths wh
en exposed to low chloride levels. We have used the aspartate-isolated mass
receptor potential of the electroretinogram (ERG) to establish whether the
: spectrally shifted cone pigment is functional. In the goldfish, Carassius
quratus, the lambda (max) of the LWS porphyropsin is displaced from about
622 nm to around 606 nm when chloride is replaced by gluconate. The electri
cal response of the LWS cones (but not MWS cones and rods) is selectively a
nd reversibly abolished by the removal of chloride ions. The effect is conc
entration dependent and a decrease to half the normal chloride ion concentr
ation is sufficient to cause a decrease in the response. (C) 2001 Elsevier
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