Evidence of muscarinic acetylcholine receptors in the retinal centrifugal system of the chick.
In this study we characterize the presence of muscarinic acetylcholine receptors (mAChR) in the isthmo-optic nucleus (ION) of chicks by immunohistochemistry with the M35 antibody. Some M35-immunoreactive fibers were observed emerging from the retinal optic nerve insertion, suggesting that they could be centrifugal fibers. Indeed, intraocular injections of cholera toxin B (CTb), a retrograde tracer, and double-labeling with M35 and CTb in the ION confirmed this hypothesis. The presence of M35-immunoreactive cells and the possible mAChR expression in ION and ectopic neuron cells in the chick brain strongly suggest the existence of such a cholinergic system in this nucleus and that acetylcholine release from amacrine cells may mediate interactions between retinal cells and ION terminals.
Calaza
K C
KC
Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brasil.
Gardino
P F
PF
D000818:Animals; D000911:Antibodies, Monoclonal / Q000032:analysis; D002645:Chickens; D007120:Immunochemistry; D009412:Nerve Fibers / Q000737:chemistry; D009900:Optic Nerve / Q000737:chemistry*; D011976:Receptors, Muscarinic / Q000032:analysis* / Q000276:immunology; D012160:Retina / Q000737:chemistry*
D000911:Antibodies, Monoclonal; D011976:Receptors, Muscarinic