Spectra of human L cones

Area of Science:

• Vision science
• Molecular biology
• Genetics

Background:

• Human cone opsins (light-sensitive proteins) exhibit amino acid variations.
• These variations lead to spectrally distinct L- and M-cone pigments, influencing color vision.
• Previous in vitro studies linked specific amino acid substitutions to altered wavelength sensitivity.

Purpose of the Study:

• To correlate in situ electrophysiological measurements of human cone spectral sensitivity with expressed cone opsin gene sequences.
• To precisely determine the spectral sensitivities of common L-cone variants in living human eyes.

Main Methods:

• Electrophysiological recordings were performed on single human cones from retinal samples.
• Cone opsin gene sequences were extracted and analyzed from the same retinal donors.
• Spectral sensitivities were measured in situ and compared with genetic data.

Main Results:

• Eight L-cone spectra were analyzed from five donors.
• The Lser180 cone variant exhibited peak sensitivity at 563 nm.
• The Lala180 cone variant showed peak sensitivity at 559 nm.

Conclusions:

• Direct in situ measurements confirm distinct spectral sensitivities for common human L-cone variants.
• Amino acid variations in cone opsins directly correlate with measurable differences in light sensitivity.
• This research provides precise in vivo data on the genetic basis of human color vision variation.