Extensive white matter tract and oligodendrocyte abnormalities are seen in cocaine misuse (Chang et al. 1997, 1999; Bartzokis et al. 1999) (see Table III). For example, MBP, proteolipid protein-1 (PLP-1), and myelin-associated oligodendrocyte basic protein (MOBP) are downregulated in chronic cocaine abuse (Albertson et al. 2004). In another microarray study, increased dlPFC PLP-1 levels were observed in four cocaine abusers, and decreased levels were observed in three other cocaine abusers (including two alcohol co-abusers); interestingly, increased dlPFC PLP-1 correlated with recent crack cocaine use (Lehrmann et al. 2003).
