Astrocyte atrophy and immune dysfunction in self-harming macaques.
BACKGROUND
Self-injurious behavior (SIB) is a complex condition that exhibits a spectrum of abnormal neuropsychological and locomotor behaviors. Mechanisms for neuropathogenesis could include irregular immune activation, host soluble factors, and astrocyte dysfunction.


METHODS
We examined the role of astrocytes as modulators of immune function in macaques with SIB. We measured changes in astrocyte morphology and function. Paraffin sections of frontal cortices from rhesus macaques identified with SIB were stained for glial fibrillary acidic protein (GFAP) and Toll-like receptor 2 (TLR2). Morphologic features of astrocytes were determined using computer-assisted camera lucida.


RESULTS
There was atrophy of white matter astrocyte cell bodies, decreased arbor length in both white and gray matter astrocytes, and decreased bifurcations and tips on astrocytes in animals with SIB. This was combined with a five-fold increase in the proportion of astrocytes immunopositive for TLR2.


CONCLUSIONS
These results provide direct evidence that SIB induces immune activation of astrocytes concomitant with quantifiably different morphology.
Tulane National Primate Research Center, Covington, Louisiana, USA.
Kim M
KM
Lee
Kevin B
KB
Chiu
Hope A
HA
Sansing
Fiona M
FM
Inglis
Kate C
KC
Baker
Andrew G
AG
MacLean
D000818:Animals; D001253:Astrocytes / Q000276:immunology / Q000473:pathology*; D001284:Atrophy / Q000276:immunology / Q000473:pathology; D048429:Cell Size; D005904:Glial Fibrillary Acidic Protein / Q000032:analysis; D008251:Macaca / Q000276:immunology / Q000502:physiology*; D016728:Self-Injurious Behavior / Q000276:immunology* / Q000473:pathology* / Q000503:physiopathology; D051195:Toll-Like Receptor 2 / Q000032:analysis
D005904:Glial Fibrillary Acidic Protein; D051195:Toll-Like Receptor 2