Methamphetamine (METH) is one of the most commonly abused psychostimulant,
and is known to induce dopaminergic neurotoxicity by generating oxidative s
tress and free radicals. In the present study we investigated the effects o
f METH on egr-1 and c-fos immediate early gene induction in different regio
ns of mouse brain, at different doses and different time courses. We also m
easured the tissue levels of monoamines in order to correlate their changes
with gene expression. A single injection of METH (40 mg/kg) significantly
increased egr-1 and c-fos mRNA expression within 30 min in frontal cortex,
nucleus accumbens, caudate putamen, septum and CAI region of hippocampus. T
ime course studies showed that in most cases, both genes were expressed wit
hin 30 min and decreased after 60 min. METH produced a significant decrease
in striatal dopamine level, reaching a very low level after 24 h. Striatal
serotonin level significantly increased and returned to control levels aft
er 2 h. These data show that METH induced egr-1 and c-fos mRNA expression i
n selective brain areas, which correlated with an alteration in monoamines.
(C) 2001 Published by Elsevier Science B.V.