Pineal activity is under the control of retinal D1-dopaminergic pathways.
The role of dopaminergic pathways in the retina in controlling the functional state of the pineal was investigated. Dopaminergic agents were injected into the eyes of dark-adapted chickens which were maintained in the dark. Changes in the activity of N-acetyltransferase (NAT) in the retina and pineal were then monitored. Injection of the non-specific dopamine agonist 6,7-ADTN depressed retinal and pineal NAT. The D1-specific agonist SKF38393 did not affect retinal NAT but depressed pineal NAT. In contrast, quinpirole, a D2-specific agonist, depressed retinal NAT, but did not depress pineal NAT. Thus, D1- rather than D2-dopaminergic pathways in the retina are involved in the retinal circuit which control pineal function.
Morgan
I G
IG
Visual Sciences Group, Research School of Biological Sciences, Australian National University, Canberra.
Boelen
M K
MK
Miethke
P
P
D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine / Q000494:pharmacology; D000818:Animals; D002642:Chick Embryo; D018491:Dopamine Agonists / Q000494:pharmacology; D004873:Ergolines / Q000494:pharmacology; D009434:Neural Pathways / Q000502:physiology*; D010870:Pineal Gland / Q000502:physiology*; D019257:Quinpirole; D017447:Receptors, Dopamine D1 / Q000502:physiology*; D012160:Retina / Q000502:physiology
D018491:Dopamine Agonists; D004873:Ergolines; D017447:Receptors, Dopamine D1; D019257:Quinpirole; D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine