title: Differential effect of postnatal lead exposure on gene expression in the hippocampus and frontal cortex.
abstract: Although developmental lead exposure is known to have detrimental effects on a variety of cognitive functions that depend on the integrity of the hippocampus and frontal cortex, little is known about how low levels of lead exposure affect expression of key families of genes in these structures. The present study examined the effects of exposure to environmentally relevant levels of lead during the sensitive early post-weaning period in the rat on the expression profiles of a select number of neurobiologically relevant genes (i.e., genes for neurotrophic factors, NMDA receptors, metabotropic glutamate receptors, synaptic function/plasticity, cell signaling, and transcription/regulation) in the rat hippocampus and frontal cortex. Exposure to lead (180 and 375-ppm lead acetate in food for 30 days) significantly increased blood lead levels (5.8 to 10.3 μg/dl) and significantly affected expression of many of the genes examined. In many instances, lead exposure had different effects on the same gene depending on the brain region in which the expression of that gene was examined. Gene expression in the frontal cortex was often more sensitive to modification than gene expression in the hippocampus. These results suggest that even past infancy, exposures to low levels of lead can have significant effects on gene expression in the frontal cortex and the hippocampus with the potential to exert long-term effects on behavior and cognition.
authors.affiliation: Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, 1020 Locust Street, 521 JAH, Philadelphia, PA 19107, USA. jay.schneider@jefferson.edu
authors.forename: J S
authors.initials: JS
authors.lastname: Schneider
authors.forename: W
authors.initials: W
authors.lastname: Mettil
authors.forename: D W
authors.initials: DW
authors.lastname: Anderson
mesh_terms: D000375:Aging / Q000187:drug effects / Q000235:genetics* / Q000473:pathology; D000818:Animals; D003072:Cognition Disorders / Q000139:chemically induced / Q000235:genetics / Q000473:pathology; D005625:Frontal Lobe / Q000187:drug effects* / Q000254:growth & development / Q000473:pathology; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects*; D006624:Hippocampus / Q000187:drug effects* / Q000254:growth & development / Q000473:pathology; D007854:Lead / Q000097:blood / Q000633:toxicity*; D020263:Lead Poisoning, Nervous System / Q000235:genetics* / Q000473:pathology; D008297:Male; D051381:Rats; D020318:Rats, Long-Evans
chemical_list: D007854:Lead