Physical activity promotes brain development through serotonin during early childhood

MAPK families play an important role in complex cellular programs like proliferation, differentiation, development, transformation, and apoptosis. At least three MAPK families have been characterized: extracellular signal-regulated kinase (ERK), Jun kinase (JNK/SAPK) and p38 MAPK. The above effects are fulfilled by regulation of cell cycle engine and other cell proliferation related proteins. In this paper we discussed their functions and cooperation with other signal pathways in regulation of cell proliferation. Show more

Over the past few decades, neuroimaging has become a ubiquitous tool in basic research and clinical studies of the human brain. However, no reference standards currently exist to quantify individual differences in neuroimaging metrics over time, in contrast to growth charts for anthropometric traits such as height and weight 1 . Here we assemble an interactive open resource to benchmark brain morphology derived from any current or future sample of MRI data ( http://www.brainchart.io/ ). With the goal of basing these reference charts on the largest and most inclusive dataset available, acknowledging limitations due to known biases of MRI studies relative to the diversity of the global population, we aggregated 123,984 MRI scans, across more than 100 primary studies, from 101,457 human participants between 115 days post-conception to 100 years of age. MRI metrics were quantified by centile scores, relative to non-linear trajectories 2 of brain structural changes, and rates of change, over the lifespan. Brain charts identified previously unreported neurodevelopmental milestones 3 , showed high stability of individuals across longitudinal assessments, and demonstrated robustness to technical and methodological differences between primary studies. Centile scores showed increased heritability compared with non-centiled MRI phenotypes, and provided a standardized measure of atypical brain structure that revealed patterns of neuroanatomical variation across neurological and psychiatric disorders. In summary, brain charts are an essential step towards robust quantification of individual variation benchmarked to normative trajectories in multiple, commonly used neuroimaging phenotypes. MRI data from more than 100 studies have been aggregated to yield new insights about brain development and ageing, and create an interactive open resource for comparison of brain structures throughout the human lifespan, including those associated with neurological and psychiatric disorders. Show more

New neurons continue to be born in the subgranular zone (SGZ) in the dentate gyrus (DG) of the adult mammalian hippocampus 1–5 . This process has been linked to learning and memory, stress and exercise, and is thought to be altered in neurological disease 6–10 . In humans, some studies suggest that hundreds of new neurons are added to the adult DG every day 11 , while other studies find many fewer putative new neurons 12–14 . Despite these discrepancies, it is generally believed that the adult human hippocampus continues to generate new neurons. Here we show that a defined population of progenitor cells does not coalesce in the SGZ during human fetal or postnatal development. We also find that proliferating progenitors and young neurons in the DG sharply decline in the first year of life and only a few isolated young neurons are observed by 7 and 13 years of age. In adult normal and epileptic patients(18–77 years; n=17 postmortem; n=12 epilepsy), young neurons were not detected in the DG. In the monkey (M. mulatta) hippocampus, a proliferative SGZ was present in early postnatal life, but diminished during juvenile development as neurogenesis declined. We conclude that recruitment of young neurons to the primate hippocampus declines rapidly during the first years of life, and that DG neurogenesis does not continue, or is extremely rare, in the adult human. The early decline in hippocampal neurogenesis raises questions about how the function of the dentate gyrus differs between humans and other species in which adult hippocampal neurogenesis is preserved. Show more