Maternal separation disrupts emotional, cognitive, and metabolic development in rats: protective and regulatory effects of environmental enrichment

Year 2026, Volume: 8 Issue: 2, 179 - 186, 10.03.2026

Serap Ata , Hamit Özyürek

https://doi.org/10.38053/acmj.1844181

https://izlik.org/JA27KA55ML

Abstract

Aims: Early-life maternal separation (MS) induces long-term metabolic and neurobehavioral disturbances, whereas environmental enrichment (EE) is considered a protective intervention; however, potential sex-dependent responses remain unclear. This study evaluated whether adolescent EE mitigates MS-related alterations in growth and emotional-cognitive outcomes and whether these effects differ between males and females.
Methods: Sprague-Dawley litters were allocated to control, MS, or MS+EE groups. MS consisted of daily 180-minute separations from postnatal day (PND) 2-14, and EE was initiated after PND14. Body weight was monitored at several developmental stages. Neurobehavioral assessments included the open field test (OFT), elevated plus maze (EPM), forced swim test (FST), and passive avoidance test (PAT). Data were analyzed using ANOVA with Tukey-Kramer post hoc comparisons.
Results: MS resulted in significantly reduced weight gain on PND7 (p<0.001). By PND28, both MS and MS+EE groups displayed greater weight gain than controls (p<0.05 and p<0.0001, respectively), with EE animals showing the highest weight by week 10 (p<0.0001), particularly males. MS decreased locomotor activity in the OFT (p<0.001), increased anxiety-like behavior in the EPM (p<0.05), elevated FST immobility (p<0.0001), and impaired PAT memory (p<0.05). EE reversed these deficits, enhancing locomotion (p<0.0001), reducing immobility (p<0.05), and improving memory retention (p<0.001). Females exhibited more pronounced anxiolytic and cognitive benefits.
Conclusion: MS produces persistent metabolic and neurobehavioral impairments, whereas EE confers significant restorative effects with notable sex-specific variation.

Keywords

Maternal separation , environmental enrichment , anxiety-like behavior , cognitive function , sex differences , body weight regulation , rats

Ethical Statement

In this study, pregnant Sprague–Dawley rats obtained from the OMU Laboratory Animals Breeding and Research Center were used, following approval from the Ondokuz Mayıs University Local Animal Experiments Ethics Committee (01/03/2010 Protocol No: 2010/10). In this study, pregnant Sprague–Dawley rats obtained from the OMU Laboratory Animals Breeding and Research Center were used, following approval from the Ondokuz Mayıs University Local Animal Experiments Ethics Committee (01/03/2010 Protocol No: 2010/10).

Supporting Institution

none

Project Number

(01/03/2010 Protocol No: 2010/10).

Thanks

The authors would like to express their gratitude to the staff of the Experimental Animals Research and Application Center of Ondokuz Mayıs University for their technical assistance and valuable contributions throughout the study.

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