Pars intermedia: unitary electrical activity regulated by light.
In the pars intermedia of frogs in the dark two types of spontaneously firing neuronal units have been found; one can be inhibited by and the other is indifferent to increases in illumination. The receptor for the light-inhibited units appears to be the pineal organ. Transection experiments indicate that the axons to the two kinds of units in the pars intermedia are separately grouped in the floor.
D000818:Animals; D001001:Anura; D001369:Axons / Q000033:anatomy & histology; D005071:Evoked Potentials; D005260:Female; D007030:Hypothalamo-Hypophyseal System / Q000502:physiology; D008027:Light; D008297:Male; D009074:Melanocyte-Stimulating Hormones / Q000378:metabolism; D009474:Neurons / Q000502:physiology* / Q000528:radiation effects; D009900:Optic Nerve / Q000601:surgery; D010870:Pineal Gland / Q000502:physiology; D010904:Pituitary Gland, Posterior / Q000033:anatomy & histology / Q000502:physiology* / Q000528:radiation effects; D011830:Radiation Effects
D009074:Melanocyte-Stimulating Hormones