Development of the human cerebral cortex: Boulder Committee revisited

Abstract

In 1970 the Boulder Committee described the basic principles of the development of the CNS, derived from observations on the human embryonic cerebrum. Since then, numerous studies have significantly advanced our knowledge of the timing, sequence and complexity of developmental events, and revealed important inter-species differences. We review current data on the development of the human cerebral cortex and update the classical model of how the structure that makes us human is formed.

The emergence of functional architecture during early brain development

“…The vast majority of these cells are formed during prenatal development (Webb et al, 2001). The brain originates from the anterior portion of the neural tube (Bystron et al, 2008;Gilbert, 2000). Following neurulation (i.e.…”

“…Following neurulation (i.e. closure of the neural tube), which starts at embryonic day 21 and is finished by day 27 (Bystron et al, 2008;Stiles and Jernigan, 2010), the precursor of the human brain rapidly expands and undergoes a series of processes including proliferation, neurogenesis and differentiation, orchestrated by an intricate genetic program (Bystron et al, 2008;Stiles and Jernigan, 2010;Webb et al, 2001). By mid-gestation neurogenesis is largely complete (Stiles and Jernigan, 2010) and during this phase, i.e.…”

“…between the third and fifth month of gestation, neuronal migration peaks with the first neurons appearing in the cortical plate by 15 postconceptional weeks (PCW) (Bystron et al, 2008;Webb et al, 2001) (Figure 1). Once neurons have reached their destination in the cortical plate, they start extending axons and dendrites (Webb et al, 2001).…”

MR connectomics: Principles and challenges

“…Indeed, our knowledge of genetic and epigenetic influences on brain development, including mechanisms governing neuronal migration and connectivity is rapidly growing, as are the genomic databases (Bystron et al, 2008;Jakovcevski et al, 2009;Mochida and Walsh, 2004) (www.ornl.gov/sci/techresources/Human Genome/home.shtml). Such large-scale genomic data combined with the high density of information provided by a contectome database will be transformative.…”

“…From birth to early adulthood the brain undergoes dramatic modifications, with neuronal loss, dendritic proliferation and axonal growth followed by reductions in synaptic plasticity, axonal pruning and myelination (Bystron et al, 2008;Innocenti and Price, 2005;Johnston et al, 2009). These processes result in gyral folding, regional specification and ultimately network optimization.…”