Sussex Neuroscience

Professor Leon Lagnado

Leon

Visual processing: synapses and circuits

The retina and brain of zebrafish provide an excellent context in which to study how neural circuits process sensory information: we can finely control the input to the circuits while observing the activity of neurons and synapses within them. We achieve this by using multiphoton microscopy to image fluorescent reporter proteins in neurons as we present visual stimuli. This approach has allowed us to analyse how excitatory and inhibitory neurons within the retinal network contribute to basic computations underlying vision, such as the detection of motion or the orientation of a spatial feature (see https://lagnadolab.com/).
Several projects are available. One will investigate adaptation within the retinal circuit – changes in the way that visual stimuli are processed according to the recent history of activity. Changes in the properties of synapses within the retina play a key role in such “network adaptation” and these changes can in turn be caused by the release of neuromodulators such as dopamine. We will ask how these substances modify the synaptic transmission of the visual signal through the retinal network and the information that is sent back to visual centers in the brain. A second potential project will focus on how neuromodulators act on the visual centers themselves.
We collaborate actively with the laboratories of Tom Baden and Chris Buckley. With Tom we investigate questions related to the function of the retina and with Chris we investigate visuo-motor processing in the brain of zebrafish within a virtual reality environment.

Selected publications
(For full list of publications and more details about the lab, please visit: https://lagnadolab.com)
Johnston, J., Seibel, S-H., Darnet, L., Renninger, S., Orger, M. & Lagnado, L. (2019). A Retinal Circuit Generating a Dynamic Predictive Code for Oriented Features. Neuron 102(6):1211-1222.
James, B Darnet L, Moya-Diaz J, Seibel S-H, Lagnado L. (2019). An amplitude code transmits information at a visual synapse. Nature Neuroscience, 22(7):1140-1147.
Rosa JM, Ruehle S, Ding H, Lagnado L. (2016). Crossover Inhibition Generates Sustained Visual Responses in the Inner Retina. Neuron, 90(2):308-19.
Lagnado, L. & Schmitz, F. (2015). Ribbon synapses and visual processing in the retina. Annual Reviews of Vision Science, 1:235-262.
Nikolaev, A., B. Odermatt, Leung, K.-M. and L. Lagnado. (2013). Synaptic mechanisms of adaptation and sensitization in the retina. Nature Neuroscience, 7:934-4171.