Role of novel projection-defined basal amygdala subregions in fear memory expression

项目总结/文摘

PROJECT SUMMARY/ABSTRACT The basal amygdala (BA) has been shown to be involved in valence-specific behaviors, including fear learning and reward behaviors. These behaviors are linked not only to genetic, anatomical, morphological, and electrophysiological characteristics of the BA, but also the various inputs and outputs of the BA. Current research has revealed the presence of four novel projection-defined subregions within the BA, each with unique brain connections that can underlie their function. Understanding learning and memory associated with the BA is especially important considering how dysregulation of tightly regulated emotional behaviors and associations can contribute to anxiety, depression, and PTSD. Therefore, understanding how information flows through the BA and its subregions along with the involvement of neuronal projections coming in and out of the BA is necessary to understand these disorders. This proposal combines brain-wide activity mapping along with in vivo calcium activity recording and neuronal manipulation to test the role of projection-defined BA subregions in the retrieval of fear and fear extinction memories. Recent advances in the characterization of BA regional connectivity will be employed to examine neuronal activity within each of the four BA subregions’ connectomes using a mouse model that can label active neurons brain-wide (Aim 1A). Next, retrogradely labeled subpopulations unique for each of the four BA subregions will be subjected to in vivo calcium activity recordings (Aim 1B) and optogenetic manipulations (Aim 2). Collectively, these aims will provide information on the correlative activity of direct inputs and outputs into and stemming from each BA subregion, activity of each BA subregion in valence-specific behaviors with particular attention to fear and extinction memories, and possible causal contributions of each BA subregion neuronal activity to fear and extinction memory expression. For successful completion of this project, the applicant will be thoroughly trained in brain-wide imaging of neuronal activity, fiber photometry, and optogenetic manipulations. In addition, the applicant will be provided with numerous opportunities for training in science communication, mentorship, and career exploration. The Reijmers and Maguire labs at Tufts University foster an environment where the applicant will be intellectually engaged and supported with all necessary facility, equipment, and guiding to ensure productive graduate training, and to prepare the applicant for a flourishing career as an independent researcher in neuroscience.