Researchers at UC San Francisco have discovered a previously unknown mass migration of inhibitory neurons into the brain’s frontal cortex during the first few months after birth, revealing a stage of brain development that had previously gone unrecognized. The authors hypothesize that this late-stage migration may play a role in establishing fundamentally human cognitive abilities and that its disruption could underlie a number of neurodevelopmental diseases.
Most neurons of the cerebral cortex — the outermost layer of the brain responsible for advanced cognition — migrate outward from their birthplaces deep in the brain to take up their positions within the cortex. Developmental neuroscientists have long thought that most neural migration ends well before an infant is born, but the new paper — published October 6, 2016 in Science — suggests for the first time that many neurons continue to migrate and integrate into neural circuits well into infancy.
“The dogma among developmental neuroscientists was that after birth all that was left was the fine wiring and pruning,” said Mercedes Paredes, MD, PhD, an assistant professor of neurology at UCSF and leader of the new study. “These results suggest there’s a whole new phase of human brain development that we had never noticed before.”
Study of donated brain tissue unveils massive neural migration after birth
The new study was a collaboration between the labs of co-senior authors Arturo Alvarez-Buylla, PhD, a UCSF professor of neurological surgery who specializes in understanding the migration of immature neurons in the developing brain, and in whose lab Paredes is a postdoctoral researcher, and Eric J. Huang, MD, PhD, a professor of pathology and director of the Pediatric Brain Tissue Bank at the UCSF Newborn Brain Research Institute.
Several recent studies — including work by Alvarez-Buylla and Huang — identified small populations of immature neurons deep in the front of the brain that migrate after birth into the orbito-frontal cortex — a small region of the frontal cortex just above the eyes. Given that the entire frontal cortex continues to expand massively after birth, the researchers sought to discover whether neural migration continues after birth in the rest of the frontal cortex… Read More>>
Source: Science Daily
