A. Snyderkeller et Rw. Keller, STIMULANT-MEDIATED C-FOS INDUCTION IN STRIATUM AS A FUNCTION OF AGE, SEX, AND PRENATAL COCAINE EXPOSURE, Brain research, 794(1), 1998, pp. 88-95
Induction of the immediate-early gene c-fos by the stimulants cocaine
and amphetamine (AMPH) was analyzed by Fos immunocytochemistry at diff
erent ages in the brains of prenatally cocaine-treated and control rat
s. Cocaine and AMPH induced c-Sos in patches of striatal neurons durin
g the first postnatal week, and thereafter produced a progressively mo
re homogeneous pattern that was more dense medially. Quantification of
Fos-immunoreactive cells in older rats revealed differences related t
o sex and prenatal cocaine treatment. Both cocaine and AMPH produced d
ose-dependent increases in the number of Fos-immunoreactive cells in s
triatum. Prenatal cocaine exposure resulted in increased Fos in males
in response to AMPH (2 mg/kg) at P18 and cocaine (10 mg/kg) at 1-2 mon
ths. In females, prenatal cocaine treatment resulted in a reduced resp
onse to cocaine at 1-2 months. Increased c-fos induction was observed
in control females compared to control males in response to low doses
of stimulants; no such sex difference was observed in prenatally cocai
ne-treated rats. The dopamine D1 antagonist SCH23390 blocked cocaine-m
ediated c-fos induction in all groups. The NMDA antagonist MK-801 bloc
ked cocaine-mediated c-fos induction in the medial striatum. In female
s only, MK-801 pretreatment resulted in a dramatic increase in the num
ber of Fos-immunoreactive cells in lateral striatum. These findings in
dicate differences in the neural basis of c-fos induction in males and
females, and changes in stimulant-mediated c-fos induction resulting
from prenatal cocaine exposure. (C) 1998 Elsevier Science B.V. All rig
hts reserved.