Early-life stress induces long-term morphologic changes in primate brain.
BACKGROUND
Traumatic experiences in early childhood are associated with increased risk of developing stress-related disorders, which are linked to structural brain abnormalities. However, it is unclear whether these volumetric brain changes are present before disease onset or reflect the consequences of disease progression.


OBJECTIVE
To identify structural abnormalities in the nonhuman primate brain that may predict increased risk of stress-related neuropsychiatric disorders in human beings.


METHODS
Rhesus monkeys were divided into 2 groups at birth: a group raised with their mothers and other juvenile and adult animals (mother reared) and a group raised with 3 age-matched monkeys only (peer reared) for the first 6 months of life. Anatomical brain images were acquired in juvenile male and female rhesus monkeys using magnetic resonance imaging.


METHODS
National Institutes of Health Animal Center in Poolesville, Maryland. Subjects Twenty-eight rhesus monkeys (Macaca mulatta) aged 24 to 30 months were used for the study.


METHODS
Volumetric measures of the anterior cingulate cortex, medial prefrontal cortex, hippocampus, corpus callosum, and cerebellar vermis were compared between mother-reared (n = 15) and peer-reared animals (n = 13).


RESULTS
Compared with mother-reared monkeys, we found an enlarged vermis, dorsomedial prefrontal cortex, and dorsal anterior cingulate cortex in peer-reared monkeys without any apparent differences in the corpus callosum and hippocampus.


CONCLUSIONS
Peer-rearing during infancy induces enlargement in stress-sensitive brain regions. These changes may be a structural phenotype for increased risk of stress-related neuropsychiatric disorders in human beings.
Spinelli
Simona
S
Developmental Cognitive Neurology, Kennedy Krieger Institute, The Johns Hopkins School of Medicine, 707 N Broadway, Baltimore, MD 21205, USA. spinellis@kennedykrieger.org
Chefer
Svetlana
S
Suomi
Stephen J
SJ
Higley
J Dee
JD
Barr
Christina S
CS
Stein
Elliot
E
D000367:Age Factors; D000818:Animals; D001921:Brain / Q000473:pathology*; D002531:Cerebellum / Q000473:pathology; D003337:Corpus Callosum / Q000473:pathology; D004292:Dominance, Cerebral / Q000502:physiology; D005260:Female; D006179:Gyrus Cinguli / Q000473:pathology; D006624:Hippocampus / Q000473:pathology; D006854:Hydrocortisone / Q000097:blood; D006897:Hydroxyindoleacetic Acid / Q000097:blood; D007091:Image Processing, Computer-Assisted; D008253:Macaca mulatta; D008279:Magnetic Resonance Imaging; D008297:Male; D008426:Maternal Deprivation; D017397:Prefrontal Cortex / Q000502:physiology; D012016:Reference Values; D012931:Social Environment; D013223:Statistics as Topic; D013313:Stress Disorders, Post-Traumatic / Q000473:pathology*
D006897:Hydroxyindoleacetic Acid; D006854:Hydrocortisone