Light–Mood Networks in Diurnal Mammals

Disrupted lighting – such as excessive nighttime light, irregular schedules, or short winter days – can increase the risk of depression and anxiety, while carefully timed light exposure can improve mood and even enhance antidepressant treatments. Yet we still know very little about how light reaches mood-regulating brain areas, or why its effects differ between individuals.

This project explores how light signals travel from the eye to key brain regions involved in emotion, and how these signals interact with serotonin, a major brain chemical linked to depression. To do this, we combine human brain imaging with experiments in a unique diurnal animal model – the sand rat – whose daily activity pattern closely resembles our own.

By revealing how light, brain activity, and biological rhythms interact, this research aims to provide a biological foundation for improved light-based therapies and more personalized treatments for mood disorders.