Electrophysiology of the guinea-pig pineal organ: sympathetically influenced cells responding differently to light and darkness.
Single cell recordings (extracellular) from the posterior part of the guinea-pig pineal organ reveals two groups of sympathetically influenced spontaneously active cells: one group is stimulated by light and inhibited by darkness; the other type of cell whose activity was monitored over a period of 15 h shows activation by darkness and diminished activity after the onset of light. It is suggested that latter type is involved in melatonin synthesis.
D000818:Animals; D004558:Electric Stimulation; D004594:Electrophysiology; D006168:Guinea Pigs; D008027:Light; D008297:Male; D008550:Melatonin / Q000096:biosynthesis; D009897:Optic Chiasm / Q000502:physiology; D010870:Pineal Gland / Q000166:cytology* / Q000378:metabolism / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D013564:Sympathetic Nervous System / Q000502:physiology*
D008550:Melatonin