title: From attachment to independence: Stress hormone control of ecologically relevant emergence of infants' responses to threat.
abstract: Young infant rat pups learn to approach cues associated with pain rather than learning amygdala-dependent fear. This approach response is considered caregiver-seeking and ecologically relevant within the context of attachment. With maturation, increases in the stress hormone corticosterone permit amygdala-dependent fear, which is crucial for survival during independent living. During the developmental transition from attachment to fear learning, maternal presence suppresses corticosterone elevation to block amygdala-dependent fear learning and re-engage the attachment circuitry. Early life trauma disrupts this developmental sequence by triggering a precocious increase of corticosterone, which permits amygdala-dependent threat responses. In this review, we explore the importance of the stress hormone corticosterone in infants' transition from complete dependence on the caregiver to independence, with consideration for environmental influences on threat response ontogeny and mechanistic importance of social buffering of the stress response.
authors.affiliation: Emotional Brain Institute, Nathan Kline Institute, New York University Langone Medical Center, New York, NY 10003; Child and Adolescent Psychiatry, New York University Langone Medical Center, New York, NY 10003; Center for Neural Science, New York University, New York, NY 10003.
authors.forename: Adrienne
authors.initials: A
authors.lastname: Santiago
authors.affiliation: Center for Neural Science, New York University, New York, NY 10003.
authors.forename: Chiye
authors.initials: C
authors.lastname: Aoki
authors.affiliation: Emotional Brain Institute, Nathan Kline Institute, New York University Langone Medical Center, New York, NY 10003; Child and Adolescent Psychiatry, New York University Langone Medical Center, New York, NY 10003; Center for Neural Science, New York University, New York, NY 10003.
authors.forename: Regina M
authors.initials: RM
authors.lastname: Sullivan
keywords: amygdala; corticosterone; development; social buffering; stress