Bipolar cells in the retina of a zebrafish expressing the glutamate reporter iGluSnFR. These allow us to image individual vesicles released at active zones.
Funding from the Wellcome Trust
We are delighted that an Investigator Award from the Wellcome Trust will fund our research for another six years beginning in 2022. The aim will be to understand the mechanisms that underly the plasticity of visual circuits.
We will use larval zebrafish, where visual circuits and the behaviours they drive are altered in the context of i) changes in the visual environment; ii) information arriving through chemical and mechanical senses; iii) information about the internal state, such as arousal or satiety, and iv) circadian mechanisms that adjust behaviour through the solar cycle.
How does a synapse encode a visual stimulus?
We recently published a paper in Nature Neuroscience titled “An amplitude code transmits information at a visual synapse“. Using the reporter iGluSnFR to image the neurotransmitter glutamate, we achieved the resolution to count individual synaptic vesicles as they are released from a single active zone in vivo. This revealed that bipolar cells transmit the visual signal using a hybrid coding strategy involving changes in both the rate and amplitude of synaptic events. We can now investigate the “vesicle code” that transmits information across a synapse.