In addition to supporting our perception of the visual environment, a significant portion of the retinal output targets elements of a so-called non-image forming (NIF) visual system. By acting to synchronise cellular circadian oscillators across the brain as well as driving much more rapid modulations in neural activity, ultimately this NIF system coordinates daily rhythms in almost every aspect of physiology and behaviour. As a consequence, unnatural patterns of light exposure (e.g. night-shift work), disrupt the ability of the NIF system to appropriately coordinate physiology and can lead to a range of detrimental effects on health. My lab aims to understand the functional organisation of the NIF visual system, with a long term goal of identifying how we can adjust the design of the visual environments in which we live to optimise health and well-being.
The key brain nuclei of the NIF visual system and well established and span regions of the hypothalamus, thalamus and pretectum. At the gross anatomical level there is abundant evidence of interconnections between these nuclei, implying that they interact to define NIF responses. However, the specific neural pathways through which the various cell-types in each region communicate visual information to one another and/or downstream targets are unknown. Our primary aims, then, are to reveal the network circuitry responsible for controlling specific NIF responses and their unique sensory characteristics. To this end we use an array of techniques including large scale electrophysiological recording, sophisticated visual stimuli, optogenetics, viral tracing and computational approaches to probe network function.