[3H]nicotine binding sites are associated with mammalian optic nerve terminals.
The autoradiographic distribution of [3H]nicotine binding sites was examined in the superior colliculus in normal rats and cats, and in animals in which one or both eyes were removed. [3H]Nicotine binding sites in normal animals were densely concentrated in the superficial layers of the colliculus corresponding to the zone of termination of optic nerve fibers. Following bilateral enucleation, [3H]nicotine binding in the superficial collicular layers was drastically reduced. Unilateral enucleation markedly reduced [3H]nicotine binding sites in the colliculus contralateral to the removed eye, with little effect on the ipsilateral colliculus. These results provide further evidence that nicotinic acetylcholine receptors have a presynaptic location on optic tract terminals and may therefore modulate retinotectal transmission in both the rat and cat visual system.
Prusky
G T
GT
Department of Psychology, Dalhousie University, Halifax, Nova Scotia.
Cynader
M S
MS
D000818:Animals; D001345:Autoradiography; D002415:Cats; D015353:Eye Enucleation; D009900:Optic Nerve / Q000737:chemistry* / Q000502:physiology; D051381:Rats; D011978:Receptors, Nicotinic / Q000032:analysis* / Q000502:physiology; D013477:Superior Colliculi / Q000737:chemistry* / Q000502:physiology; D014785:Vision, Ocular / Q000502:physiology; D014795:Visual Pathways / Q000737:chemistry / Q000502:physiology
D011978:Receptors, Nicotinic