Behavioural brain researchOct 18, 2026

Maternal melatonin treatment reduces behavior changes and causes sex-specific brain signaling differences in adult offspring exposed to constant light before birth

Circadian Biology Weekly Brief ↗PubMed ↗DOI ↗

Updated Oct 19, 2026

Abstract

Maternal treatment with piromelatine resulted in reduced anxiety and improved working memory in adult offspring exposed to constant light during pregnancy.

Offspring from piromelatine-treated mothers showed less anxiety- and depression-like behavior compared to those from vehicle-treated mothers exposed to constant light.
Improvements in working memory were observed in both male and female offspring from piromelatine-treated mothers.
Analysis of locomotor activity indicated variability in 24-hour rhythms across different groups without significant treatment effects on overall rhythmicity measures.
Hippocampal levels of a protein involved in signaling (pCREB) and a growth factor (BDNF) were higher in male offspring from piromelatine-treated mothers compared to the vehicle group.
No direct evidence was found to confirm that the observed molecular changes directly caused the behavioral improvements.

Simplified

Maternal exposure to constant light during pregnancy (CLE) is associated with disrupted circadian organization and persistent behavioral alterations in adult offspring. This study examined behavioural performance and 24-hour locomotor activity patterns, as well as hippocampal pCREB and BDNF levels, in adult male and female offspring following prenatal CLE and maternal treatment with piromelatine (pir), which acts as an agonist at melatonin MT1/MT2 and serotonin 5-HT1A/5-HT1D receptors. Pregnant Wistar rats under light-dark regime received vehicle (veh), whereas dams exposed to CLE received vehicle (LL-veh), pir (10 mg/kg), or melatonin. Compared to the LL-veh groups, offspring from pir-treated dams exhibited reduced anxiety- and depression-like responses and improved working memory in both sexes. Individual-subject cosinor analysis revealed heterogeneous 24-hour locomotor rhythmicity within and between groups. No significant treatment-group effect was detected for MESOR or amplitude, and the descriptive acrophase patterns did not provide evidence of treatment-induced restoration or normalization of circadian organization. Maternal pir treatment was associated with higher hippocampal pCREB and BDNF levels in male, but not female offspring relative to the LL-veh group. While the behavioral and molecular differences occurred concurrently in males, these findings do not prove that pCREB/BDNF signaling mediated the behavioral outcomes. Furthermore, the study cannot distinguish the direct developmental effects of maternal pir exposure from those mediated through maternal or offspring circadian rhythm. Therefore, the findings should be interpreted as long-term behavioral and sex-specific molecular differences associated with maternal pir treatment rather than as evidence of circadian-independent antidepressant, anxiolytic, cognitive-enhancing, or BDNF-enhancing actions.

Full Text

Full text is available at the source.

View Full Text ↗

Maternal melatonin treatment reduces behavior changes and causes sex-specific brain signaling differences in adult offspring exposed to constant light before birth

Abstract

Full Text

You found one interesting study. We’ll send the next 7.

What Lands in Your Inbox Each Week:

Recent issues from the circadian biology brief