Normal Development of Brain Circuits

Abstract

Spanning functions from the simplest reflex arc to complex cognitive processes, neural circuits have diverse functional roles. In the cerebral cortex, functional domains such as visual processing, attention, memory, and cognitive control rely on the development of distinct yet interconnected sets of anatomically distributed cortical and subcortical regions. The developmental organization of these circuits is a remarkably complex process that is influenced by genetic predispositions, environmental events, and neuroplastic responses to experiential demand that modulates connectivity and communication among neurons, within individual brain regions and circuits, and across neural pathways. Recent advances in neuroimaging and computational neurobiology, together with traditional investigational approaches such as histological studies and cellular and molecular biology, have been invaluable in improving our understanding of these developmental processes in humans in both health and illness. To contextualize the developmental origins of a wide array of neuropsychiatric illnesses, this review describes the development and maturation of neural circuits from the first synapse through critical periods of vulnerability and opportunity to the emergent capacity for cognitive and behavioral regulation, and finally the dynamic interplay across levels of circuit organization and developmental epochs.

Differences in brain morphology and working memory capacity across childhood

“…Of particular interest was the anatomy of white matter. White matter changes are thought to be a key process in postnatal brain development, which continues throughout childhood and adolescence into early adulthood (Barnea‐Goraly, 2005; Muftuler et al., 2012; Qiu, Tan, Zhou, & Khong, 2008; Tau & Peterson, 2010). In particular, the myelination of axons is thought to be a critical mechanism of brain development in this age range (Miller et al., 2012).…”

Psychoneuroimmunology of Early-Life Stress: The Hidden Wounds of Childhood Trauma?

“…Of note, these processes of neuronal development take place according to regional patterns (heterochronicity), which are typically seen earlier in females than males (Brenhouse and Andersen, 2011a). Synaptogenesis, synaptic refinement, and myelination all occur in a stereotypical posterior-to-anterior direction, first seen in the sensory and motor cortical areas, then in association cortical areas and the corpus callosum, and eventually in the frontal lobe (Levitt, 2003;Tau and Peterson, 2010). Subcortical patterns are more poorly understood.…”

“…Other developmental processes, such as synaptogenesis, synaptic refinement, myelination, and neurogenesis also start in fetal life, but continue after birth, in some cases well into adult life. These cellular events set the foundation for higher-order processes of brain development (Brenhouse and Andersen, 2011a;Casey et al, 2008;Crone and Dahl, 2012;Giedd and Rapoport, 2010;Tau and Peterson, 2010). Here we provide a brief overview of the key postnatal maturational events driving brain development.…”

“…These include proliferation and migration of neuronal precursors (Tau and Peterson, 2010). Other developmental processes, such as synaptogenesis, synaptic refinement, myelination, and neurogenesis also start in fetal life, but continue after birth, in some cases well into adult life.…”

“…Here we provide a brief overview of the key postnatal maturational events driving brain development. Neuronal development Key postnatal cellular events contributing to brain development are listed below (Tau and Peterson, 2010). Synaptogenesis is the formation of synapses between neurons, which takes place starting in fetal life (second trimester) and continues during infancy and, at a slower pace, during childhood.…”