The retina contains photoreceptors that mediate the dual tasks of image formation and irradiance (brightness) detection. Our research focuses on how environmental irradiance regulates physiology and behaviour. These non-image forming responses to light include the regulation of the circadian clock, locomotor activity, sleep/wake timing, pupil constriction, pineal melatonin synthesis, body temperature and heart rate. The photoreceptors regulating these responses to light include the rods and cones which mediate image-forming vision as well as the recently identified photosensitive retinal ganglion cells (pRGCs) expressing the photopigment melanopsin.
The central aims of this work are to understand how light information is transmitted from photoreceptor to brain and to identify the signalling pathways in both the retina and target nuclei. In addition to understanding of the basic mechanisms underlying irradiance detection, our research also addresses how these responses are affected by disease. Research in the group relies upon a wide range of techniques, including molecular biology, immunocytochemistry, in vitro and in vivo gene silencing, as well as behavioural assays of circadian activity, sleep, visual performance and physiological parameters such as body temperature.