Translational Control in Memory and Brain Disorders

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Project Summary/Abstract Over the last 15 years, several laboratories, including my laboratory, have identified multiple signaling pathways that regulate translation via the translation initiation factors eIF4E and eIF2α during protein synthesis-dependent forms of long-lasting synaptic plasticity and various memory processes in rodents, including the consolidation, reconsolidation, and extinction of auditory and contextual threat memory. These findings have generated much excitement because they demonstrate the complex biochemical regulation of translation during synaptic plasticity and memory. Despite this progress, a number of critical and unresolved questions regarding the requirement for de novo protein synthesis in memory consolidation remain unanswered. We plan to focus on auditory and contextual threat memory to determine the cell types in the amygdala and hippocampus, respectively, that require eIF4E- and eIF2α-dependent translation for memory consolidation, reconsolidation, extinction, and discrimination. We also plan to examine the cell type-specific requirement for de novo translation in memory using more complex types of behavioral paradigms, including Dysregulated translation has been shown by a number of laboratories, including my laboratory, to contribute to synaptic dysfunction and aberrant behaviors in neurodegenerative diseases such as Alzheimer’s disease (AD) and neurodevelopmental disorders such as fragile X syndrome (FXS) and autism spectrum disorder (ASD). However, using molecular approaches to dissect circuit dysfunction in these diseases/disorders has been lacking. Therefore, we plan to examine the role of cell type-specific translational dysregulation in mouse models of AD, FXS, and ASD. Moreover, we will identify the inappropriately translated mRNAs and their newly synthesized protein products using translatomic and de novo proteomic approaches that we developed to identify mRNAs/proteins that are translated/synthesized improperly in mouse models of AD and FXS. These questions will be addressed by utilizing the powerful multidisciplinary combination of new groundbreaking genetically-engineered mice and viruses, electrophysiological recordings, immuno-cytochemistry, innovative methods to measure de novo protein synthesis in vivo, cell-type specific translational profiling, and de novo proteomics. The results of these studies will provide fundamental insights into the molecular events in both excitatory and inhibitory neurons that support consolidation, reconsolidation, and extinction of memory. Moreover, these studies have the potential to provide therapeutic targets for multiple brain disorders that are associated with dysregulated translation.