You are here:
CHANGES IN HIPPOCAMPAL SPINE DENSITY AND PROTEIN KINASE C ISOFORMS FOLLOWING DEVELOPMENTAL EXPOSURE TO A MIXTURE OF PERSISTENT CHEMICALS.
Citation:
Kodavanti, P., J. Yang, AND R. F. Mervis. CHANGES IN HIPPOCAMPAL SPINE DENSITY AND PROTEIN KINASE C ISOFORMS FOLLOWING DEVELOPMENTAL EXPOSURE TO A MIXTURE OF PERSISTENT CHEMICALS. Presented at (Dioxin 2002) 22nd International Symposium on Halogenated Environmental Pollutants and POPs, Barcelona, Spain, 8/11-16/2002.
Description:
Polychlorinated biphenyls (PCBs) offer a unique model to understand the major issues related to complex environmental mixtures of persistent chemicals. These pollutants are ubiquitous, persistent, bioaccumulate in human body through the food chain, and exist as mixtures of several congeners in the environment. Human exposures to PCBs are associated with a variety of adverse health effects including neurobehavioral changes and neuroendocrine disruption1. It is of a particular concern that exposure to relatively low levels during development may be associated with neurological deficits such as impairments in learning and memory2. During the past decades there has been an attempt to understand the cellular and molecular basis of PCB-induced behavioral and neurotoxic effects in animal models. Recent in vivo studies from our laboratory indicated that developmental exposure to a commercial PCB mixture, Aroclor 1254R, caused perturbations of calcium homeostasis and changes in protein kinase C (PKC) activities in rat brain3. While PCBs are known to disturb several neurochemical endpoints, it is not known which molecular substances are targets for PCB-induced developmental neurotoxicity. The PKC signaling pathway has been implicated in the modulation of learning and memory, and the roles of PKC are subspecies specific. Also, PKC has been shown to modulate dendritic differentiation and growth4. In neurons, dendritic branching and spines parameters represent the anatomical substrate for the input of information to neurons. Indeed, dendritic parameters comprise over 95% of the surface area of the typical neuron. As such, change in dendritic morphology may result in a significant effect on the transfer of information in neural circuits and would inevitably influence neurobehavioral performance. The purpose of the present study was to assess the effects of developmental exposure to a commercial mixture of PCBs (Aroclor 1254) on PKC isoforms and neuronal dendritic morphology of hippocampal CA1 pyramidal neurons.