Utility of Fetal Movement Coordination in Assessing Nervous System Functioning after Prenatal Administration of the Neurotoxin Methylazoxymethanol (MAM)

Abstract

It is now thought that some neuromotor disorders (e.g., cerebral palsy, ALS, Parkinson disease) may be the result of toxin exposure early in development. Consequently, methods to assess impairments in early nervous system functioning are of considerable interest to both researchers and clinicians. While such methods already have been developed for the postnatal period, few tools exist for the assessment of fetal nervous system functioning. Behavioral measures used in our lab have shown clear developmental patterns, suggesting they may be useful in detecting early assaults to the central nervous system. To test this hypothesis, pregnant rats were given an injection of the neurotoxin methylazoxymethanol (MAM) on E17 of gestation. On E20, 72 hours later, fetuses were prepared for in vivo testing, which consisted of the following behavioral observations: (a) spontaneous movement, (b) facial wiping in response to lemon infusion, and (c) response to an artificial nipple presentation. Quantification of these three measures showed clear disruptions of movement coordination in the MAM-treated subjects, with no discernable differences from saline controls in weight or anatomical measures. These findings suggest that prenatal behavioral assessments of motor coordination, either spontaneous or evoked, may be useful in identifying neural insult during fetal development