AJP - Regulatory, Integrative and Comparative Physiology, Vol 240, Issue 3 220-R228, Copyright © 1981 by American Physiological Society
Sites and action spectra for encephalic photoreception in the Japanese quail
J. D. Glass and J. K. Lauber
Sexually mature Japanese quail, Coturnix coturnix japonica, were
transferred to short environmental photoperiod for 20 days, during which
they received encephalic illumination via surgically implanted optic
fibers. White light delivered to discrete sites in the basal hypothalamus
induced photogonadal response for testicular maintenance. There was also a
strong positive response to monochromatic red, green, or blue light
delivered to these areas, and this response was of equal magnitude
regardless of wavelength. Illumination of sites in the median eminence and
pars nervosa was also effective in inducing photogonadal response. White
light delivered to the optic chiasma was effective, whereas green or blue
light to this structure had no effect. Illumination of the preoptic
hypothalamus or the dorsal cortex was also without effect. Our data
indicate that there are photoreceptive sites in and near the basal
hypothalamus that, when illuminated directly, are capable of responding to
a broad range of visible wavelengths.
