Information processing in the nucleus accumbens

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DESCRIPTION (provided by applicant): The nucleus accumbens is a brain region with an important role in processing reward information and the selection of behaviors appropriate to the context. It has been proposed that one mechanism by which context guides response selection in the nucleus accumbens is via a synaptic interaction that has been characterized as a gating mechanism; hippocampal inputs are believed to be necessary for other inputs to drive action potential firing in the nucleus accumbens. Although the gating hypothesis has received further support from several studies, novel data indicate that the nucleus accumbens could disengage from its hippocampal inputs and follow prefrontal activity during epochs in which selection of a behavior is required. We proposed that the nucleus accumbens can behave a switchboard where response selection takes place by the interactions among multiple afferents. Here we will test whether the integration of information in the nucleus accumbens is critical for decision-making and selection of the appropriate behavioral response to a given context using multichannel recordings (simultaneously from the prefrontal cortex, hippocampus and nucleus accumbens) in two different operant tasks. Furthermore, we will explore the synaptic mechanisms underlying these interactions with in vivo intracellular recordings and whole cell recordings in accumbens slices, aimed at testing whether strong prefrontal afferent activation can attenuate the impact of hippocampal afferents and whether this interaction is dependent on local GABA or dopamine. Unveiling the cellular and synaptic processes responsible for response selection in the nucleus accumbens would advance our understanding of this critical function and pave the way to novel views on the pathophysiology of neuropsychiatric disorders, including schizophrenia, and perhaps eventually seek novel therapeutic approaches. PUBLIC HEALTH RELEVANCE: This project will test whether the integration of information in the nucleus accumbens is critical for decision-making and selection of the appropriate behavioral response to a given context. In particular, we will assess the manner activity in the prefrontal cortex affects the influence exerted by the hippocampus on nucleus accumbens electrical activity and the behaviors that depend on it. Such integration of information in this critical brain region is important for understanding decision making and response selection and gaining an understanding of its mechanism will helps us develop better models to explain mental disorders.