First Author | Sethuramanujam S | Year | 2016 |
Journal | Neuron | Volume | 90 |
Issue | 6 | Pages | 1243-1256 |
PubMed ID | 27238865 | Mgi Jnum | J:270885 |
Mgi Id | MGI:6279660 | Doi | 10.1016/j.neuron.2016.04.041 |
Citation | Sethuramanujam S, et al. (2016) A Central Role for Mixed Acetylcholine/GABA Transmission in Direction Coding in the Retina. Neuron 90(6):1243-1256 |
abstractText | A surprisingly large number of neurons throughout the brain are endowed with the ability to co-release both a fast excitatory and inhibitory transmitter. The computational benefits of dual transmitter release, however, remain poorly understood. Here, we address the role of co-transmission of acetylcholine (ACh) and GABA from starburst amacrine cells (SACs) to direction-selective ganglion cells (DSGCs). Using a combination of pharmacology, optogenetics, and linear regression methods, we estimated the spatiotemporal profiles of GABA, ACh, and glutamate receptor-mediated synaptic activity in DSGCs evoked by motion. We found that ACh initiates responses to motion in natural scenes or under low-contrast conditions. In contrast, classical glutamatergic pathways play a secondary role, amplifying cholinergic responses via NMDA receptor activation. Furthermore, under these conditions, the network of SACs differentially transmits ACh and GABA to DSGCs in a directional manner. Thus, mixed transmission plays a central role in shaping directional responses of DSGCs. |