Summary
Abnormal light exposure during the first three weeks of life — conditions analogous to those experienced by preterm infants in NICUs — produces lasting changes in the stress (HPA) axis, circadian rhythms, and mood-related behaviour in mice. These findings highlight the importance of providing appropriate light-dark cycling in neonatal care environments to support healthy long-term neurodevelopmental and stress system outcomes.
Key Findings
- Mice reared under constant light (LL) showed altered neuropeptide and glucocorticoid receptor expression in the brain compared to normal 12:12 LD controls.
- Constant darkness (DD) rearing produced a blunted corticosterone stress response in female mice but had no significant effect in males.
- LL-reared mice exhibited increased depressive-like behaviour in adulthood, while learning/memory and anxiety behaviour were unaffected by postnatal light manipulation.
- LL rearing conferred resilience to rhythm-disrupting effects of constant light in adulthood, with maintained locomotor activity, body temperature, and corticosterone rhythms.
- Maternal care and maternal stress systems were not significantly altered by the different light conditions, suggesting direct effects on offspring rather than mediation through changes in maternal behaviour.
Categories
Neonatal Care: Examines how abnormal postnatal light environments (constant light or darkness) during the first three weeks of life affect long-term stress system development in mice, relevant to NICU lighting conditions for preterm infants.
Sleep & Circadian Health: Demonstrates that early-life light exposure shapes long-term circadian rhythm resilience and HPA axis function, including corticosterone rhythms and locomotor activity patterns.
Mood & Mental Wellness: Constant light rearing during the postnatal period resulted in increased depressive-like behaviour in adult mice, suggesting lasting mood-related consequences of early light environment.
Author(s)
G Coleman
Publication Year
2014
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