The Effect of Wavelength on the Organization of the Reptilian Visual System.
Final rept. 1 May 69-30 Apr 70,
EYE RESEARCH FOUNDATION BETHESDA MD
Pagination or Media Count:
Spectral sensitivity curves were derived for cells isolated in the optic tectum of turtle. All cells were most sensitive to the red region of the visible spectrum with some cells showing a secondary peak in the blue-green region. The majority of cells showed an on-off response to wide field monochromatic stimulation. Plots of spectral sensitivity for on and off responses were often the same and the shapes of these curves suggested antagonistic inputs from spectrally different processes. In other cells distinct differences were noted in the sensitivity functions for the on and off portions of the response although both curves appeared to be the result of the combination of the same two visual pigments. In a third group of cells a complete shift in the elicited response pattern was observed with stimulus wavelengths at one end of the spectrum eliciting an on response and at the opposite end, an off response. The data suggest that the reptilian optic tectum may be involved in hue discrimination.
- Anatomy and Physiology