Present address: Laboratory of Perinatal Stress, JE2365, University of Lille 1, France.
Beneficial effects of enriched environment on adolescent rats from stressed pregnancies
Article first published online: 6 SEP 2004
European Journal of Neuroscience
Volume 20, Issue 6, pages 1655–1664, September 2004
How to Cite
Laviola, G., Rea, M., Morley-Fletcher, S., Di Carlo, S., Bacosi, A., De Simone, R., Bertini, M. and Pacifici, R. (2004), Beneficial effects of enriched environment on adolescent rats from stressed pregnancies. European Journal of Neuroscience, 20: 1655–1664. doi: 10.1111/j.1460-9568.2004.03597.x
- Issue published online: 6 SEP 2004
- Article first published online: 6 SEP 2004
- Received 20 January 2004, revised 15 June 2004, accepted 17 June 2004
- environmental enrichment;
- prenatal stress;
- social behaviour
The capacity of an early environmental intervention to normalize the behavioural and immunological dysfunctions produced by a stressed pregnancy was investigated. Pregnant Sprague-Dawley rats underwent three 45-min sessions per day of prenatal restraint stress (PS) on gestation days 11–21, and their offspring were assigned to either an enriched-environment or standard living cages throughout adolescence [postnatal days (pnd) 22–43]. Juvenile rats from stressed pregnancies had a prominent depression of affiliative/playful behaviour and of basal circulating CD4 T lymphocytes, CD8 T lymphocytes and T4/T8 ratio. They also showed increased emotionality and spleen and brain frontal cortex levels of pro-inflammatory interleoukin-1β (IL-1β) cytokine. A more marked response to cyclophosphamide (CPA: two 2 mg/kg IP injections) induced immunosuppression was also found in prenatal stressed rats. Enriched housing increased the amount of time adolescent PS rats spent in positive species-typical behaviours (i.e. play behaviour), reduced emotionality and reverted most of immunological alterations. In addition to its effects in PS rats, enriched housing increased anti-inflammatory IL-2 and reduced pro-inflammatory IL-1β production by activated splenocytes, also producing a marked alleviation of CPA-induced immune depression. In the brain, enriched housing increased IL-1β values in hypothalamus, while slightly normalizing these values in the frontal cortex from PS rats. This is a first indication that an environmental intervention, such as enriched housing, during adolescence can beneficially affect basal immune parameters and rats response to both early stress and drug-induced immunosuppression.