Epigenetics in Cognition
Epigenetics in Cognition
What is memory and how are memories formed at the cellular and molecular levels? Decades of research have yet to pinpoint definitive answers to these questions, however, recent studies in the field of epigenetics suggest that modifications to chromatin structure may play an important role. Epigenetics was first discussed in the context of developmental biology and was proposed to be the mechanism that allows for cellular differentiation by determining and maintaining the "correct" gene expression profile for a given cell type. The biochemical changes that mediate epigenetic regulation include chromatin modifications, such as DNA methylation, histone modification, and ATP-dependent nucleosome remodeling. In addition to their role in cell type determination and stable maintenance of genes expression patterns, chromatin modifications also play a role in the dynamic regulation of gene expression in post mitotic cells. Several studies have shown that DNA methylation and histone modifications are dynamically regulated in neurons in response to external cues. This type of environmentally induced epigenetic plasticity has been implicated in complex neuronal processes like learning and memory. These post-mitotic neuro-epigenetic mechanisms may provide a resolution for the dichotomy of "Nature vs. Nurture" since we now know that the environment (Nurture) can directly affect gene activity (Nature) in our brains.rnrnThere are hundreds of evolutionarily conserved proteins involved in the regulation of chromatin structure. My lab takes a systems-biology approach to understand the role of these proteins in the brain. To do this we use the fantastic and highly efficient model organism, Drosophila melanogaster, to analysis genomic and epigenomic processes underlying learning and memory. We also aim to understand more about the contribution of epigenetic regulators to human cognitive disorders, like Intellectual Disability (ID).
- Chubak M.C., Nixon K.C.J., Stone M.H., Raun N., Rice S.L., Sarikahya M., Jones S.G., Lyons T.A., Jakub T.E., Mainland R.L.M., Knip M.J., Edwards T.N., and Kramer, J.M., (2019) Individual components of the SWI/SNF chromatin remodeling complex have distinct roles in memory neurons of the Drosophila mushroom body Dis. Model Mech. 12(3):pii: dmm037325 [PubMed]
- Nixon, K.C.J.*, Rousseau, J.*, Stone, M.H., Sarikahya, M., Ehresmann, S., Mizuno, S., Matsumoto, N., Miyake, N., DDD study, Baralle, D., McKee, S., Izumi, K., Ritter, A., Heide, S., Héron, D., Depienne, C., Titheradge, H., Kramer, J.M.*, and Campeau, P.M.*, (2019) A syndromic neurodevelopmental disorder caused by mutations in SMARCD1, a core SWI/SNF subunit needed for context dependent neuronal gene regulation in flies Am J Hum Genet. 104(4):596-610 [PubMed]
- Riahi H., Brekelmans C., Foriel S, Merkling S.H., Kleefstra T., van Rij R.P., Kramer J.M.*, Schenck A.*, (2018) The histone methyltransferase G9a regulates tolerance to oxidative stress-induced energy consumption PLoS Biol. 17(3):e2006146 [PubMed]
- Jones S.G., Nixon K.C.J., and Kramer J.M., (2018) Mushroom body specific transcriptome analysis reveals dynamic regulation of learning and memory genes after acquisition of long-term courtship memory G3: Venes, Genomes, Genetics 8(11):3433-3446 [PubMed]