Yehezkel Ben-Ari, INMED-INSERM, France
April A. Benasich, Center for Molecular & Behavioral Neuroscience, Rutgers University-Newark, U.S.A.
Julia Lupp, Ernst Strüngmann Forum, Frankfurt, Germany
Charles A. Nelson, Harvard University, U.S.A.
Urs Ribary, Simon Fraser University and University of British Columbia, Canada
Wolf Singer, ESI for Neuroscience in Cooperation with the Max-Planck-Society, Frankfurt, Germany
Terry Sejnowski, Salk Institute, La Jolla, CA 92037, U.S.A.
Synchronization of oscillations among brain areas across development is thought to mediate network assembly, coordination, and plasticity and to support emerging cognition, perception, and language. This process depends crucially on ongoing neural plasticity and the exquisite sensitivity to environmental cues that characterize early brain development. Many studies suggest that dynamic coordination is a key factor in these experience-dependent changes. Exploration of how maturational trajectories of local and large-scale brain networks unfold as well as the role that oscillatory mechanisms play in this process is a topic of intense interest across disciplines. Although much research has been conducted in this domain using animal models, similar questions are just beginning to be actively explored and defined in human development. However, the physiological mechanisms by which functionally related intrinsic and extrinsic elements are attended to, selected, and incorporated to construct evolving, maturing networks, and the computational theories that are invoked to describe this process, are still imprecisely defined.
For example, how is brain coordination accomplished at multiple levels across age? What central mechanisms are critical to maturation of the developing brain, and what roles do critical/sensitive periods play across maturation for both typical and atypical development. We know that the dynamics of local and long-range networks, within critical periods, are influenced by many factors (including genetics, epigenetics, neurotransmitter systems, cell-to-cell interactions and variation in structure and function) and that this equation may be altered either concurrently or predicatively in a number of neuropsychiatric disorders.
Several studies have shown that early insults, whether genetic or environmental, heavily impact developmental sequences of ionic currents and brain patterns leading to the presence of immature activity in the adult brain. These aberrant oscillations and synchronizations and/or enhanced or reduced functional connectivity constitute preclinical signatures of future disorders. The underlying concept is that pathological neurons recapitulate, to some extent, more immature neuronal stages. Such events have been shown to occur in relation to autism and migration disorders but may also be a factor in ADHD and LLDs. These issues have not been sufficiently investigated due to the large number of genetic mutations and putative relevant animal models and the difficulty of performing detailed anatomo-physiological studies of their features in embryonic brains. As a result, no consensus exists on the extent to which developmental and neuropsychiatric disorders may reflect early disruption in dynamic coordination and/or a failure to establish structural and functional connectivity and synchronization between cortical areas that support emerging cognitive processes. Thus, further investigation on a number of fronts, including the properties of misplaced and misconnected neurons, is essential.Top of page
Dynamic coordination over development is a rapidly expanding area of study, yet many unanswered questions persist as well as divergent views on how to approach such questions. Through this Forum we hope to make headway in defining key components across local and large-scale networks over development. Intense discussion within four working groups will be employed to identify gaps in current knowledge, identify priorities in this relatively unexplored area, and provide recommendations for multidisciplinary basic and clinical research. Overarching issues to be explored in all groups include: