Alcohol in Neocortex Development and Plasticity

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DESCRIPTION (provided by applicant): Fetal Alcohol Spectrum Disorders (FASD) is an umbrella term describing a range of effects that can occur in an individual whose mother imbibed alcohol during pregnancy. This condition is considered the leading cause of mental retardation in the western world with as many as 40,000 cases per year in the United States. The sensory cortex is one of the most affected areas in FASD and children with this condition present altered somatosensory, auditory and visual processing. There is growing evidence indicating that these sensory problems may be related to poor cortical map refinement, organization and plasticity. However, the mechanisms that underlie such effects remain to be elucidated. We developed a unique ferret model of FASD that provides a novel approach to test mechanistic hypothesis of how early alcohol exposure can impair sensory cortex function. We showed that third trimester alcohol exposure lead to a persistent disruption in visual cortex organization and neuronal plasticity. In recent years, much attention has been devoted to the control of neuronal function by astrocytes. It has been shown that molecules secreted by astrocytes can regulate synaptic formation, stabilization and plasticity. Many of these astrocyte-released molecules are mediated by the transcription factor SRF (Serum Response Factor). Here we hypothesize that inappropriate SRF function in astrocytes contributes to the impairment of neuronal plasticity seen in FASD. As a corollary, improvement of SRF function in astrocytes may ameliorate this deficit. To test this hypothesis we will use multiple techniques such as viral-mediated gene transfer, ex vivo gene delivery, in vivo optical imaging of intrinsic signals, in vivo extracellular electrophysiology, monotypic cell cultures, confocal laser microscopy and multiple biochemical and molecular assays. Collectively, this proposal will help our understanding of how early alcohol exposure affects astrocyte to neuron signaling and its effects on cortical plasticity. This information may be highly relevant to devise therapeutic interventions for FASD