the evidence for the proposal that the excitatory amino acids glutamate and aspartate are transmitters of photoreceptors , that gamma-aminobutyric acid ( gaba ) is the inhibitory transmitter of horizontal and amacrine cells , that acetylcholine is associated with the functioning of bipolar cells , and that taurine , glycine and dopamine may all also play neurotransmitter or neuromodulatory roles at amacrine cell synapses is discussed .
C0007634
cells
C0039062
synapses