Prof Leon Lagnado – University of Sussex
Dr Sylvia Schroeder – University of Sussex
Dr Christian Wilms – Scientifica Ltd
As early as one synapse away from the eye, visual signals are integrated with feedback from higher visual areas and even signals reflecting internal brain states (Schröder et al., 2020).
In this project, you will discover how retinal, cortical and neuromodulatory inputs shape the responses of visual neurons in the superior colliculus.
The goal of your PhD project is to understand the mechanisms of signal integration, i.e. which inputs to the superior colliculus shape its neural activity, and the advantages of this integration for visual processing.
You will use two-photon imaging in awake mice to simultaneously record activity of neurons in the superior colliculus as well as of axons originating in the retina, visual cortex, or brainstem nuclei such as the dorsal raphe (serotonin). You will compare the responses of the axonal inputs to those in the neurons, and you will observe how these signals change depending on the visual input and the behaviour of the animal.
In the beginning of your project, you will develop an advanced imaging technique in collaboration with our industrial partner, Scientifica. You will adapt the existing two-photon microscope to image two separate fields of view simultaneously (Stirman et al, 2016). This technique, termed multi-region imaging, will enable you to record inputs and outputs of superior colliculus at sufficient detail, speed, and quantity.
This project will advance our understanding of early visual processing and the integration of bottom-up and top-down neural signals. The prototype of a multi-region detection system will allow Scientifica to develop a full product, bringing the power of this method to researchers not able to adapt their microscopes themselves.