Module 8: Figure brain development
Stages of brain development.
Brain development begins within a few weeks when embryonic cells begin to proliferate to generate the large numbers of progenitor cells. These progenitors become connected together through gap junctions and begin to generate Ca2+ signals that initiate at a pacemaker cell and then spread out to their neighbours to produce large numbers of hubs. Neuronal precursor cells within these hubs then differentiate into excitatory (green cells) and inhibitory neurons (red cells) as evident by the axonal and dendritic sprouting. These neurons then begin to form synapses with each other to form recognizable neural circuits. Some of the information used to draw this Figure was obtained from de Graaf-Peters and Hadders-Algra (2006).