Critical period regulation acrossmultiple timescales

• Type of Material: Article
• Authors: Rebecca K. Reha, University of British Columbia; Brian Dias, Emory University; Charles A. Nelson, III, Harvard Medical School; Daniela Kaufer, University of California Berkeley; Janet F. Werker, University of British Columbia; Bryan Kolbh, University of Lethbridge; Joel D. Levine, University of Toronto; Takao K. Hensch, Harvard Medical School
• Language: English
• Date: 2020-09-22
• Publisher: PNAS
• Publication Version: Final Published Version
• Copyright Statement: Published under the PNAS license
• Final Published Version (URL): http://dx.doi.org/10.1073/pnas.1820836117
• Title of Journal or Parent Work: Proceedings of the National Academy of Sciences of the United States of America
• Volume: 117
• Issue: 38
• Start Page: 23242
• End Page: 23251
• Grant/Funding Information: All authors are members of the Canadian Institute for Advanced Research Child Brain Development network. This work was supported by Natural Sciences and Engineering Research Council of Canada Discovery Grant 81103 (to J.F.W.), National Institute of Mental Health Grant P50MH094271, and World Premier International Research Center Initiative–International Research Center for Neurointelligence (to T.K.H.).
• Keywords: critical period; Brain; parvalbumin; Parvalbumins; Neuronal Plasticity; Humans; circadian clock; Circadian Clocks; Neurons; gamma oscillations; Animals; Time Factors
• Research Categories: Biology, Neuroscience

Abstract

Brain plasticity is dynamically regulated across the life span, peaking during windows of early life. Typically assessed in the physiological range of milliseconds (real time), these trajectories are also influenced on the longer timescales of developmental time (nurture) and evolutionary time (nature), which shape neural architectures that support plasticity. Properly sequenced critical periods of circuit refinement build up complex cognitive functions, such as language, from more primary modalities. Here, we consider recent progress in the biological basis of critical periods as a unifying rubric for understanding plasticity across multiple timescales. Notably, the maturation of parvalbumin-positive (PV) inhibitory neurons is pivotal. These fast-spiking cells generate gamma oscillations associated with critical period plasticity, are sensitive to circadian gene manipulation, emerge at different rates across brain regions, acquire perineuronal nets with age, and may be influenced by epigenetic factors over generations. These features provide further novel insight into the impact of early adversity and neurodevelopmental risk factors for mental disorders.