ARND--IMPACT ON SYNAPTIC PLASTICITY MECHANISMS

点击翻译按钮获取中文摘要

DESCRIPTION: (Adapted from the Investigator's Abstract) Learning disabilities are among the most subtle yet most pervasive deficits related to prenatal alcohol exposure in children. These learning deficits, which may not become apparent until a child is school-aged, can occur in the absence of other physical evidence of alcohol-related birth defects. Offspring of rats exposed to moderate levels of alcohol during gestation also show a significant impairment in learning when tested as young adults, validating the use of this animal model in studies of the effect of fetal alcohol exposure (FAE). Initial studies by our integrative research program suggested that these deficits are related to specific alterations in synaptic plasticity mechanisms which correlated with a failure in the establishment of long-term potentiation (LTP). The long-term objectives of this Integrated Research Program Grant (IRPG) are two-fold: 1)to delineate more clearly the molecular and neurochemical alterations of synaptic plasticity mechanisms caused by prenatal alcohol exposure and 2) to explore new treatment strategies to overcome these deficits. The overall hypothesis for the IRPG is that prenatal exposure to moderate levels of ethanol produces multiple defects in the mechanisms underlying glutamate levels of ethanol produces multiple defects in the mechanisms underlying glutamate receptor-dependent LTP in the hippocampus and medial frontal cortex. The specific goal of Project 3 in this IRPG is to define the impact of FAE on the levels and function of proteins involved in synaptic plasticity mechanisms. Based upon preliminary studies, our hypothesis is that protein kinase C (PKC) activity and the levels and phosphorylation of GAP-43 and other important plasticity-associated proteins is altered in specific brain regions of FAE rats. To test this idea, we propose the following Specific Aims: 1)to study PKC activity and the phosphorylation of GAP-43 and other PKC substrate proteins in the hippocampus and medial frontal cortex of FAE rats, both under basal conditions and after electrical stimulation 2)to examine the impact of FAE on activity-dependent changes in GAP-43 phosphorylation and gene expression during behavioral conditioning, 3) to characterize the causes for the deficit in PKC activity in FAE rats and to evaluate its significance in synaptic plasticity mechanisms and 4) to investigate the effects of different pharmacological treatments on PKC activity and GAP-43 phosphorylation in control and FAE rats and 5) to relate these to the behavioral and electrophysicological properties of the animals. The identification of the neurochemical basis for the alterations in synaptic plasticity in the hippocampus and medial frontal cortices of FAE rats will improve our understanding of the effects of prenatal alcohol exposure in the function of these important brain structures. Ultimately, this information will help design better therapeutic strategies to overcome behavioral and cognitive deficits in children affected with Alcohol Related Neurodevelopmental Disorders (ARND).