Understanding the contribution of early-life light environment to circadian clock function in adulthood

Circadian rhythms are a fundamental feature of life.

In mammals, these ~24h rhythms are endogenously generated by a brain clock within the suprachiasmatic nucleus (SCN) that critically synchronises body functions to the prevailing light-dark cycle. Circadian clocks are essential for health and wellbeing.

Circadian disruption in adults is associated with common medical problems, including metabolic, mood, and sleep disorders, imposing a serious public health threat. At birth, the SCN is not fully developed and completes maturation postnatally.

Evidence indicates that postnatal lighting environment can influence SCN development and result in long-lasting changes in its function that persist into adulthood.

However, we currently lack a comprehensive description of the impact of early-life lighting on adult circadian phenotypes, while the neurobiological mechanisms responsible for such effects remain almost entirely unknown.

Using state-of-the-art electrophysiological, imaging, and behavioural methods, I aim to determine the impact of postnatal lighting environment (i) on the neurophysiological properties of the juvenile circadian clock and (ii) on the circadian system in adulthood.

As common laboratory rodents are nocturnal and avoid light, I propose using a novel diurnal murid rodent to better recreate the human experience.

This project will establish a foundational description of the effects of early-life lighting on circadian biology in laboratory animals.

Understanding the contribution of early-life lighting experiences to adult circadian function and the biological mechanisms involved will have the potential to inform new interventions to promote circadian health and improve developmental care practices to support optimal circadian system maturation and long-term wellbeing.