Benjamin Schwartz's Abstracts

Benjamin Schwartz
Ph.D. Candidate
Neuroscience

Society for Neuroscience (SfN) Annual Meeting

Chicago, IL
October 19-23, 2019

The critical period is a time of maximal plasticity within the cortex. The progression of the critical period is marked by experience-dependent transcriptional alterations in cortical neurons, that in turn shifts the excitatory-inhibitory balance in the brain and accordingly, reduces plasticity. Epigenetic mechanisms, such as DNA methylation, control the transcriptional state of neurons, and has been shown to be dynamically regulated during the critical period. Here we show that adult animals have a significantly higher concentration of DNA methylation than critical period animals. Pharmacological reduction of DNA methylation in adult animals reestablishes critical period auditory map plasticity. Furthermore, the reduction of DNA methylation in adult animals, reverted intrinsic characteristics of inhibitory synapses to an immature state. Our data suggests that accumulation of DNA methylation during the critical period confers a mature phenotype to cortical neurons, which in turn, facilitates the reduction in plasticity seen after the critical period.  

Abstract for Lay Audience

My research centers around the field of plasticity. Plasticity is the ability of the nervous system to respond to intrinsic or extrinsic stimuli by reorganizing its structure, function, and connections. Or in other words, plasticity describes the brains innate ability to change. Levels of plasticity fluctuate throughout life, however, early in development, during a time referred to as the critical period, plasticity reaches its maximal levels. During this time in early development, the high levels of plasticity facilitate the establishment of the sensory and motor maps that are required for proper brain function. As early development progresses, plasticity progressively weakens until the critical period ends, where plasticity stays at a reduced level throughout adulthood. This phenomena of gradually weakening plasticity during development explains why it is significantly harder to learn languages as an adult compared to as a child. The goal of my research is to better understand the mechanisms that gradually weaken plasticity as the critical period closes. Understanding the closure of the critical period is of vital importance for understanding how plasticity is regulated in the brain. My research could provide a framework for understanding how to re-establish critical period plasticity in adulthood, which would represent a crucial finding within the field of neuroplasticity. Furthermore, more in-depth knowledge regarding critical period re-opening, gained from this research, could be used to help children who have suffered from neglect. Neglected children have been robbed of the crucial early life experiences that shape the structure and function of the brain. The result is often developmental defects that hinder basic human functions such as language, motor skills, and vision. Information from this research could be used to re-establish critical period plasticity in neglected children, which would provide a second chance for them to receive the experience necessary for proper brain development.