Light stimulates tyrosine hydroxylase activity and dopamine synthesis in retinal amacrine neurons.
Retinal dopamine-containing amacrine neurons are rapidly activated by light, as shown by an increase in the rate of dopamine formation in vivo and a concomitant increase in the activity of tyrosine hydroxylase, measured in vitro with a subsaturating concentration of pteridine cofactor. Activation of tyrosine hydroxylase also occurs when isolated eyes from rats killed in the dark are exposed to a strobe light. Studies of amacrine neurons should provide basic data about the biochemical processing of visual information, as well as the physiological presynaptic regulatory mechanisms of dopamine-containing neurons.
D000818:Animals; D002940:Circadian Rhythm; D004298:Dopamine / Q000096:biosynthesis*; D004789:Enzyme Activation / Q000528:radiation effects; D007700:Kinetics; D008027:Light; D008297:Male; D009474:Neurons / Q000378:metabolism; D051381:Rats; D012160:Retina / Q000166:cytology / Q000201:enzymology / Q000378:metabolism*; D014446:Tyrosine 3-Monooxygenase / Q000096:biosynthesis*
D014446:Tyrosine 3-Monooxygenase; D004298:Dopamine