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Updated: Aug 8, 2026
Assessment of Perigenital Sensitivity and Prostatic Mast Cell Activation in a Mouse Model of Neonatal Maternal Separation
Published on: August 13, 2015
Long-lasting changes in behavioural and neuroendocrine indices in the rat following neonatal maternal separation:
Helge A Slotten1, Mikhail Kalinichev, Jim J Hagan
1Institute of Neuroscience, School of Biomedical Sciences, Queen's Medical Centre, University of Nottingham, NG7 2UH, Nottingham, UK. helge.slotten@nottingham.ac.uk
Insights
Neonatal maternal separation (MS) in rats leads to long-term, gender-specific changes in behavior and stress response. Early life stress impacts adult neurochemistry and anxiety levels, particularly in males.
Area of Science:
- Neuroscience
- Behavioral Science
- Endocrinology
Background:
- Neonatal maternal separation (MS) is a model for early-life stress.
- MS can induce long-term neurochemical and behavioral alterations.
- Understanding these effects is crucial for developmental research.
Purpose of the Study:
- To characterize behavioral and neuroendocrine changes after MS in rats.
- To investigate long-term effects of MS on anxiety and stress reactivity.
- To identify gender-specific responses to early-life stress.
Main Methods:
- Rats underwent daily maternal separation (3h) on postnatal days 3-15.
- Behavioral tests (elevated plus-maze, T-maze, locomotor activity) were conducted from postnatal day 90.
- Adrenal weight, plasma corticosterone, and ACTH were measured basally and after stress.
Main Results:
- Adult MS rats showed increased body weight compared to controls.
- MS males exhibited shorter T-maze emergence latencies.
- MS rats displayed higher spontaneous ambulation; males were less active than females.
- Basal corticosterone was lower in MS females; adrenal glands were smaller in MS animals.
- Stress reactivity showed no MS-related differences post-restraint.
Conclusions:
- The MS paradigm induces lasting, gender-dependent behavioral and HPA axis alterations.
- Consistent gender differences highlight distinct effects of early stress on male and female rats.
- Findings expand knowledge on altered anxiety and stress responses in rats exposed to early-life adversity.
Abstract:
Neonatal maternal separation (MS) has been used to model long-term changes in neurochemistry and behaviour associated with exposure to early-life stress. This study characterises changes in behavioural and neuroendocrine parameters following MS. On postnatal days (PND) 3-15, male and female Long-Evans rats underwent 3 h daily MS. Non-handled (NH) control offspring remained with the dams. Starting at PND 90, behaviour was assessed at weekly intervals in the elevated plus-maze, elevated T-maze, and locomotor activity boxes, and body weight monitored throughout. At the end of the study, adrenals were weighed and blood collected for analysis of plasma corticosterone and adrenocorticotropic hormone (ACTH) under basal conditions and following restraint stress. As adults, MS weighed more than NH animals. Activity on the open arms of the plus-maze was similar between MS and NH animals. In the T-maze, MS males had shorter emergence latencies than their NH counterparts. Spontaneous ambulation in a novel environment was significantly higher in MS than in NH animals, and males exhibited overall lower activity than females. Basal plasma corticosterone was lower in MS than in NH females, but no rearing condition difference was observed following restraint stress. Females had higher corticosterone and ACTH levels than males, whereas adrenal glands of MS animals weighed less than those of NH controls. The MS paradigm caused long-term gender dependent effects on behaviour and HPA axis status. The consistent gender differences confirm and expand existing results showing altered anxiety and stress reactivity in male and female rats.
