Data from: Hair and plasma cortisol throughout the first three years of development in infant rhesus macaques, Macaca mulatta

Cortisol expression has been demonstrated to have variation across
development in rhesus macaques (Macaca mulatta). There exists
contradictory evidence for the nature of this change, and age at which it
occurs, across biological sample types. Consequently, we lack a cohesive
understanding for cortisol concentrations across the development of a
major human health translational model. We examined hair cortisol
concentrations over the first three years of life for 49 mother-reared
infant macaques from mixed-sex outdoor units at the California National
Primate Research Center. For 48 of these subjects at infancy, one year,
and two years, we obtained plasma cortisol samples for: response to a
stressor, adjustment to prolonged stress, and response to dexamethasone
injection. Hair cortisol concentrations decreased dramatically between
three and ten months, followed by relative stability up to the final
sampling event at around 34 months of age. Plasma cortisol showed
within-year consistency, and consistency between infancy and year one. We
document variability in the infant plasma cortisol samples, especially in
percent change between samples one and two. Our plasma cortisol results
indicate that infants possess the physiological capacity to effectively
inhibit the release of cortisol when stimulated, as effectively as later
responses in juveniles. Age-related changes in hair cortisol parallel
findings indicating a large decline in the weeks following
postparturation.