ADOLESCENT LIGHT–DARK CYCLE DISRUPTION ALTERS NEUROBEHAVIOURAL FUNCTION AND CORTICO-HIPPOCAMPAL STRUCTURE: PRELIMINARY EVIDENCE FOR MODULATORY EFFECTS OF NANOCURCUMIN

Adolescence is a critical period of brain maturation characterised by heightened synaptic remodelling and increased sensitivity to circadian disruption. Alterations of the light–dark cycle through prolonged light exposure can disrupt sleep–wake regulation and negatively influence neurodevelopment and behaviour. The neurobehavioral and structural consequences of protracted light exposure during adolescence, and the potential modulatory effects of nanocurcumin (bioavailable antioxidant) were evaluated.
Male adolescent mice (4weeks old) were exposed to prolonged light conditions (19:5 h light–dark cycle) for 4weeks, with or without concurrent oral administration of nanocurcumin, while age-matched controls were maintained under a standard 12:12 h light–dark cycle. Neurobehavioral outcomes were assessed immediately after, using the Open Field, Y-maze, and Morris Water Maze. Histological analyses of the hippocampus and prefrontal cortex were performed to evaluate structural integrity.
Mice exposed to prolonged light exhibited reduced exploratory behaviour, impaired spontaneous alternation, and deficits in spatial learning, indicating anxiety-like and cognitive alterations. These behavioural changes were accompanied by neuronal loss and cytoarchitectural disorganisation in hippocampal subregions and the prefrontal cortex. Across behavioural paradigms, mice receiving nanocurcumin consistently performed closer to control levels and also had preserved cytoarchitecture, suggesting a partial protective effect against light-induced neurobehavioral disturbances. These findings highlight adolescence as a vulnerable window during which environmental light perturbation and sleep disruption may alter brain structure and function. Nutraceutical interventions such as nanocurcumin may modulate neuroplastic responses to environmental stressors. Ongoing longitudinal follow-up will determine whether these early alterations persist or resolve over time, providing insight into long-term neurodevelopmental resilience.