Human brain contains highly connected regions called “hubs” that are very important for efficient neuronal signaling and communication. In mature individual hubs are constantly found in precuneus, cingulate gyrus, frontal cortex and interior parietal regions. Evidences reveal that because of this highly functional human brain, the hubs support information integration for complex cognitive function. In line with this, abnormal hubs have been implicated to various neurological brain disorders. So the central role of hubs in human brain at the beginning of human life is valuable. Since, it offers insight about the origins of psychiatric and developmental disorders of the human brain at the later life.
Location of hubs in fetal human brain
Hubs were located in cerebellum, inferior temporal gyrus, angular gyrus, precentral gyrus, primary visual cortex and medial temporal lobe. Several hubs found in sensory and motor brain areas. Overall, more hubs were observed in the left rather than the right hemisphere suggesting asymmetry of hub association. Also hubs found in areas close to adult facial fusiform and homologous areas. Taken together, results suggest that hubs emerge before birth and serves as the important building block in human brain development.
This is the first research study about the functional hubs in human brain prior to birth. It reveals that within the organization of fetal brain there are hubs that are already important for neural efficiency. Particularly in both primary and association brain regions shows centrality in network before birth. The fetal brain network is not wired exclusively for perception but instead, prepare the brain for higher cognitive functioning in later life.
Hence, the network organization of fetal human brain contains hubs that are central to the architectural neural circuitry. Hubs were identified in motor and visual areas as well as in association cortices of the fetal brain. Interestingly, many hubs were localized in cerebellar region supporting the idea that hubs emerge in areas early to myelinate. It is hypothesized that, because of high centrality in network, hub regions generates neural activity that stimulates myelin. Additionally, hubs are significant for global efficiency of the fetal human brain network for higher cognitive functioning and serve as biomarkers for neurodevelopmental disorders.
Source: Prepared by Joan Tura from Developmental Cognitive Neuroscience
Volume 30, April 2018, Pages 108-115