Functions of acetylcholine in signal processing and development of the mammalian retina

Acetylcholine (ACh) was the first biological substance to be identified as a neurotransmitter. In spite of this relatively long history, the functions of acetylcholine in biological systems are still in the process of being elucidated. In the retina, which is responsible for the receipt and initial processing of light information for use by the visual system, acetylcholine has at least two functions: as a neurotransmitter and as an important molecule helping to organize the development of retinal cells.