Widespread axonal damage in the brain of drug abusers as evidenced by accumulation of beta-amyloid precursor protein (beta-APP): an immunohistochemical investigation.
BACKGROUND
In drug abusers, white matter changes have been described by neuroimaging analyses in different brain regions. A specific pattern of involvement or a predominance of a specific brain region could not be drawn.


OBJECTIVE
To examine alterations of the white matter as a possible morphological substrate of the neuroimaging findings.


METHODS
Brain specimens of 30 polydrug abusers and 20 controls were obtained at autopsy. The white matter from 11 different brain regions was analysed by means of immunohistochemistry for beta-amyloid precursor protein (beta-APP), a marker of axonal damage.


RESULTS
In the white matter of polydrug abusers, beta-APP-immunopositive accumulations were increased significantly compared to controls. They were more prominent in the brains of younger drug abusers than in those of the elderly. With the exception of five cases (four polydrug abusers and one control case), there were no significant white matter changes seen on myelin-stained sections, but there was a concomitant microglial activation.


CONCLUSIONS
Our results show a significant axonal damage in the brains of polydrug abusers, which might represent the morphological substrate of a chronic-progressive drug-induced toxic-metabolic process. It is yet to be established if the observed changes are responsible for the alterations seen in different neuroimaging analyses and which drugs of abuse might be of major pathogenetic significance.
Büttner
Andreas
A
Institute of Legal Medicine, Ludwig-Maximilians University, 80337 Munich, Germany. andreas.buettner@med.uni-muenchen.de
Rohrmoser
Katharina
K
Mall
Gita
G
Penning
Randolph
R
Weis
Serge
S
D000293:Adolescent; D000328:Adult; D016564:Amyloid beta-Protein Precursor / Q000378:metabolism*; D001369:Axons / Q000187:drug effects* / Q000378:metabolism; D001927:Brain Diseases / Q000378:metabolism*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D009410:Nerve Degeneration; D019966:Substance-Related Disorders / Q000378:metabolism*
D016564:Amyloid beta-Protein Precursor