Between 10% and 15% of infants born in urban America today have been exposed to cocaine in utero. Clinical studies have suggested that impairment of brain growth is the single best marker of significant prenatal cocaine exposure, and postnatal developmental compromise seen in a subset of affected children as a consequence of that exposure. We have developed an animal model, in mice, of prenatal cocaine exposure that has allowed us to dissociate the direct effects of cocaine in altering fetal development from the indirect effects associated with cocaine-induced malnutrition. We find that transplacental cocaine exposure independently impairs fetal brain and body growth and results in behavioral deficits and permanent alterations in neocortical cytoarchitecture in exposed offspring.
To characterize the effects of cocaine on developing brain we have developed a mouse model of gestational cocaine exposure. We studied pregnant dams injected twice daily with cocaine HCl at 40, 20, or 10 mg/kg/day sc from embryonic days (E)8 to E17 (COC 40, COC20, and COC10, respectively), vehicle-injected dams allowed access to food ad libitum (SAL) or pair-fed with the COC 40 dams (SPF 40), animals pretreated with the short-acting alpha-adrenergic antagonist phentolamine prior to each cocaine injection (P COC 40), and animals administered phentolamine prior to saline (PHENT). COC 40, P COC 40, and SPF 40 dams demonstrated the lowest percentage weight gain during gestation. The surrogate-fostered offspring of COC 40, P COC 40, and SPF 40 dams demonstrated transient brain and body growth retardation on postnatal days (P)1 and P9 when compared to pups born to SAL dams. We conducted behavioral tests which allowed us to dissociate the indirect effect of cocaine-induced malnutrition from a direct effect of prenatal cocaine administration in altering postnatal behavior. Pups from all groups were tested for first-order Pavlovian conditioning on P9 or P12 or for the ability to ignore redundant information in a blocking paradigm on P50. Unlike the SPF 40, PHENT, and SAL controls, COC 40 and P COC 40 mice were unable to acquire an aversion to an odor previously paired with shock on P9, a learning deficit that resolved by P12. However, on P50, COC 40 mice and, to a lesser extent, P COC 40 and SPF 40 mice demonstrated a persistent behavioral deficit in our blocking paradigm, which may reflect alterations in selective attention. We discuss how these findings in our rodent model have developmental implications for human infants exposed to cocaine in utero.
Sophisticated health care consumers are beginning to use the Internet to educate themselves about their own health and manage their own care. As health care stakeholders (providers, payers, employers) feel pressure from consumers to implement Internet-related strategies, stakeholders must realize that obtaining Internet access is a challenge for many consumers. Stakeholders who expand consumer Internet access will, however, have a competitive advantage. This article outlines how stakeholders can expand consumer Internet access.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.