Effects of Light Intensity, Wavelength and Quanta on Gonads and Spleen of the Deer Mouse

LIGHT affects the activity of several endocrine organs of higher vertebrates. In birds the phenomenon usually requires a sufficiently long photoperiod, in some cases the response is intensity-dependent, and in others wavelength appears to be a key factor 1–3 . The gonads of birds maintained in red light weighed more than those of birds kept in blue or green light of the same intensity 4–11 . Not only the pituitary-gonadal axis, but also the adrenal cortex 12 , thyroid 13 and pineal 14 of birds are affected by the photoenvironment.