Comparison of Prenatal and Post-Weaning Lead Exposure and Enriched Versus Impoverished Rearing Environment on Visuospatial Learning and Memory in Rats

By: Nicolas G. Tolman '13, Chelsea N. Louis '14, Gwen Galvin '14

Advising Faculty: Joseph A. Schroeder

A wealth of evidence has indicated that exposure to excessive amounts of inorganic lead during early development can produce long-lasting cognitive deficits in humans. Evidence also suggests that children raised in an impoverished environment are at a disproportionate risk for developing lead-induced cognitive deficits compared with peers exposed to an enriched environment. This study compared the effects of prenatal and post weanling lead exposure and environmental enrichment on visuospatial working and long-term memory in rats. Pregnant rats were fed 1500 ppm lead acetate-laced rat chow starting on day 10 of gestation through lactation. Additional groups of rats were fed either standard or lead-laced chow beginning at weaning for 7 weeks and were exposed to either enriched or impoverished rearing conditions. Long-term and working memory error rates were assessed during a 17-day radial arm maze (RAM) learning task. Results suggest that pre-weanling and in utero lead exposure has significant detrimental effects on reference memory performance. However, an isolated post-weanling rearing environment was overall more detrimental to cognitive performance than lead exposure and an enriched rearing environment was neuroprotective against the toxic effects of lead.

Related Fields: Neuroscience