Localization of acetylcholine receptors during synaptogenesis in retina.

Nicotinic acetylcholine receptors are synthesized in chick embryo retina before synapses appear. Most of the receptors are found associated with neurites in the inner synaptic layer of the retina; later in development the receptors appear in the outer synaptic layer. Cells dissociated from retina and cultured in vitro form aggregates and also sort out into regions comprised either of neurites or cell bodies. Most of the nicotinic acetylcholine receptors of aggregates are found associated with neurite regions. The receptor distribution of cultured retina cells thus resembles that of intact retina.