Risk, resilience, and gene-environment interplay in primates

Area of Science:

• Behavioral Neuroscience
• Genetics
• Primatology

Background:

• Social stressors, such as separation from familiar individuals, can profoundly affect biological and behavioral responses.
• Individual differences in stress reactivity exist within rhesus monkey populations.
• Understanding gene-environment interactions is crucial for comprehending stress responses.

Purpose of the Study:

• To demonstrate significant interactions between genetic and social environmental factors on rhesus monkey stress responses.
• To investigate the mechanisms underlying these gene-environment interactions.
• To examine how these interactions influence biological and behavioral outcomes throughout development.

Main Methods:

• Longitudinal studies of rhesus monkeys in captive and naturalistic settings.
• Examination of individual differences in biological and behavioral responses to stress.
• Analysis of genetic factors, including specific gene polymorphisms, and their interplay with environmental influences.

Main Results:

• Approximately 20% of monkeys exhibit heightened fearful and anxious behaviors, along with depressive-like symptoms and prolonged hypothalamic-pituitary-adrenal (HPA) axis activation in response to social stress.
• A specific serotonin transporter gene polymorphism is linked to neurobehavioral deficits and extreme stress responses in infants with insecure early attachments.
• Maternal "buffering" (secure attachment) mitigates the impact of genetic predispositions on stress responses, a phenomenon that can extend across generations.

Conclusions:

• Specific gene-environment interactions critically shape behavioral and biological reactions to social stress in rhesus monkeys.
• These interactions influence stress responses throughout an individual's development.
• Maternal buffering mechanisms can transmit protective effects across successive generations, impacting offspring carrying "risk" alleles.