Environmental Enrichment Intervention
Objective: To determine whether environmental enrichment during the peripubertal period can reverse the effects of early maternal separation on HPA axis and behavioral stress responses
Protocol Steps
Early Maternal Separation
Subjects were subjected to postnatal maternal separation to induce stress reactivity and increase HPA axis responsiveness
Note: This is the initial manipulation that increases hypothalamic CRF gene expression and HPA responses
View evidence from paper
“Postnatal maternal separation increases hypothalamic corticotropin-releasing factor (CRF) gene expression and hypothalamic-pituitary-adrenal (HPA) and behavioral responses to stress”
Peripubertal Environmental Enrichment Intervention
Environmental enrichment was applied during the peripubertal period to reverse the effects of maternal separation
Note: Environmental enrichment completely reversed the effects of maternal separation on both HPA and behavioral responses to stress
View evidence from paper
“environmental enrichment during the peripubertal period completely reverses the effects of maternal separation on both HPA and behavioral responses to stress”
Assessment of HPA Axis Response
HPA axis responses to stress were measured following the enrichment intervention
Note: Environmental enrichment led to functional reversal of HPA stress responses
View evidence from paper
“environmental enrichment leads to a functional reversal of the effects of maternal separation through compensation for, rather than reversal of, the neural effects of early life adversity”
Assessment of Behavioral Stress Responses
Behavioral responses to stress were measured following the enrichment intervention
Note: Behavioral stress responses were completely reversed by environmental enrichment
View evidence from paper
“environmental enrichment during the peripubertal period completely reverses the effects of maternal separation on both HPA and behavioral responses to stress”
Measurement of CRF mRNA Expression
Hypothalamic CRF mRNA expression was measured to determine if enrichment reversed the neural effects of maternal separation
Note: Environmental enrichment had no effect on CRF mRNA expression, indicating compensation rather than reversal of neural effects
View evidence from paper
“environmental enrichment during the peripubertal period completely reverses the effects of maternal separation on both HPA and behavioral responses to stress, with no effect on CRF mRNA expression”