Establishing an intersection between epigenetic control of MTOR gene expression with genetic and environmental factors regulating learning and memory

Mammalian brain development and adult behaviour are influenced by early life experiences. The mechanism associated with the persistence of environmentally induced effects remains in question. Evidence has revealed that conditions during pregnancy and early postpartum generate stable differences in the offspring, in part, via altered gene expression in certain cell types and specific brain regions. Chromatin modification and DNA methylation are two global mechanisms that regulate gene expression. Metabolic signaling, in turn, can affect the expression and activity of the enzymes that modify chromatin and gene expression. Herein, assessing interindividual differences in chromatin modifications and DNA methylation marks holds great potential for determining the impact of both early life experience as well as the effect of interventions that alter metabolic processes, and ultimately neural gene expression, on brain development and adult behaviour. We recently demonstrated, using rodent behavioural and physiological measures along with pathway focused gene expression analysis, fluorescent microscopy, immunoprecipitation and bisulfite pyrosequencing--based approaches, that gestational stress inhibits the expression of enzymes that modify chromatin, which in turn inhibits expression of the mechanistic target of rapamycin (mTOR) network that regulates DNA repair, metabolism and cell growth. This unexpected finding offers the opportunity to contrast the chromatin structural--metabolic relationships, critical for neural cell growth and survival, in response to conditions during pregnancy and early postpartum, and how they relate to the development of cognitive, social and emotional behaviours. This is a challenging task and requires sensitive structural probes at the cellular level that can be used in concert for analysis with physiological and behavioural testing techniques. To this end, I have assembled a strong team of students and collaborators, experienced in the following techniques: video tracking system for automating rodent behavioural observations; extracellular flux analyzer for interrogating metabolism in live cells; confocal microscopy for chromatin imaging; laser capture and FACS analysis to isolate specific cell populations; digital RT--qPCR to measure genome--wide and candidate gene expression from single cells; ATAC--Seq, and bisulfite pyrosequencing for nucleosome and DNA methylation analysis, and ChIP---Seq for protein-DNA interaction analysis; primary culture systems and cell lines for temporal and functional analysis of neurons. We will combine these cutting--edge approaches with transgenic animal models and human brain tissues to provide a complete picture of how experiences propagate from external to internal variables, and what role chromatin structure and remodelling genes play in conical and non--conical pathways underlying the biological embedding of early in life effects on brain development and adult behavioural phenotypes.