Which neurotransmitter is associated with amacrine cell signaling in the retina?

• A. Acetylcholine
• B. Dopamine
• C. GABA
• D. Glutamate

Answer: (A)

Amacrine cells act as signaling modulators between bipolar and ganglion cells in the inner retina. A well-characterized subset, the starburst amacrine cells, is cholinergic, meaning they release acetylcholine. This acetylcholine release onto neighboring ganglion cells, especially those involved in direction-selective responses, is a hallmark of amacrine cell signaling in this context. While many amacrine cells use GABA as an inhibitory transmitter, the distinctive association emphasized in this scenario is acetylcholine due to the role of starburst amacrine cells in shaping retinal motion detection. Dopamine, GABA, and glutamate have their own roles in retinal signaling, but the most classic amacrine-cell–associated transmitter highlighted here is acetylcholine.