Patterns of Behavioral Development after Low-Dose Prenatal Toxin Exposure

Abstract

<p>Recent interest has been generated in a phenomenon known as the Fetal Basis of Adult Disease (FeBAD), where prenatal insults lead to a silent damage or vulnerability that does not emerge as a functional deficit until later in life. Although numerous outcome studies have documented this phenomenon, little is known about functional changes that take place across early development after a prenatal insult. In this cross-sectional study, pregnant rats were exposed to a low dose (10 mg/kg) of the neurotoxin methylazoxymethanol (MAM, Midwest Research Institute), by intraperitoneal injection on E17 (day 17 of a 21 day gestation). At subsequent prenatal and postnatal ages (E18-PlOL direct observations of behavior were made using a battery of early behavioral measures. Juvenile and adolescent rats (P30 & P45) were also observed in a series of open field tests. Collectively, these observations reveal deficits that emerge in waves across development at the peak expression of each newly emerging behavior. This pattern of variability in the timing and expression of behavioral deficits reveals, for the first time experimentally, the possible pattern of prenatal behavioral development likely to be observed during the emergence of FeBAD. Because deficits were transient, revealed only at time points early in the peak expression of newly emerging behaviors, traditional outcome measures are unlikely to detect this type of neural insult. Consequently, these results suggest that the best methods for detection and investigation of neural insults likely to produce the effects of FeBAD are quantitative measures designed to assess the early emergence of behavior.</p><p>This presentation occurred at the Wright State University Campus-Wide Celebration of Research, Scholarship and Creative Activities on April 8, 2011</p>