Male rats exposed to cocaine in utero demonstrate elevated expression of Fos in the prefrontal cortex in response to environment.
Prenatal cocaine exposure has been associated with disruption in attention and short-term memory in exposed children and in animal models. The biochemical change or changes responsible for these cognitive deficits are not known. An intriguing possibility, however, is that cocaine exposure during development disrupts the morphology or function of the frontal cortex, a region thought to contribute to cognitive and executive functions. In this report, we examined the effects of intravenous prenatal cocaine exposure on the expression of the immediate-early gene, c-fos, in the adolescent offspring to determine potential sites of disruption. The expression of Fos protein was similar in unhandled rats prenatally treated with saline or cocaine. Prenatal cocaine exposed rats that were handled, but not footshocked, however, demonstrated a dramatic selective increase in Fos expression in the ventral and medial prefrontal cortex. A footshock-induced increase in Fos expression in the prefrontal cortex was noted in prenatal saline, but not prenatal cocaine rats. Interestingly, no differences were noted in baseline or footshock-induced increased Fos expression in nuclei of the amygdala in prenatal cocaine and prenatal saline rats, indicating some aspect of the central response to stress appear unchanged. The unusual activation of the neurons of the medial and ventral prefrontal cortex may be a consequence of in utero cocaine exposure that contributes to the reported deficit in cognition.
Morrow
Bret A
BA
Department of Pharmacology, Yale University School of Medicine, 333 Cedar St., New Haven, CT 06520-8066, USA. bret.morrow@yale.edu
Elsworth
John D
JD
Roth
Robert H
RH
D000818:Animals; D003042:Cocaine / Q000494:pharmacology*; D018765:Dopamine Uptake Inhibitors / Q000494:pharmacology*; D004777:Environment; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D017781:Genes, Immediate-Early; D016762:Genes, fos / Q000187:drug effects* / Q000502:physiology; D008297:Male; D017397:Prefrontal Cortex / Q000187:drug effects* / Q000378:metabolism; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D051381:Rats
D018765:Dopamine Uptake Inhibitors; D003042:Cocaine