Pineal response types in the frog's brain under white light exposure.

Responses to white light stimulation can be recorded with electrophysiological methods at the level of (1) the pineal system (2) different diencephalic nuclei and (3) the mesencephalic tegmentum. The neurons are classified in six groups according to their discharge characteristics. As some responses present a higher complexity than the classical messages, an integration of the pineal informations during their course toward the brain is suggested in order to support phototactic behavior.