The brain circuitry is made up of an enormous number of neurons. It is constructed by sequential developmental steps, involving neuronal differentiation, migration, axon guidance, and synaptogensis. The resulting wiring patterns determine the characteristics of animals’ behavior and mental activities. Although the brain maintains a certain degree of plasticity, the core element is almost fixed and non-rewireable after the completion. We focus on this rigid feature of the brain by attempting to reveal the rules of neural development and to understand how the wiring design shapes brain function.
Ventral aspects of three mouse embryonic brains with different genotypes. Olfactory bulb (arrowheads) neurons and their axons are labeled in blue. (left) in the normal brain, olfactory bulb axons grow around the ventral brain part and make neural circuits. (middle, right) in mutant brains for axon guidance molecules, the axons ectopically grow and make aberrant connections.
Yamauchi, K., Yamazaki, M., Abe, M., Sakimura, K., Lickert, H., Kawasaki, T., Murakami, F., and Hirata, T. (2017). Netrin-1 derived from the ventricular zone, but not the floor plate, directs hindbrain commissural axons to the ventral midline. Sci Rep 7, 11992.
Zhu, Y., Matsumoto, T., Nagasawa, T., Mackay, F., and Murakami, F. (2015). Chemokine signaling controls integrity of radial glial scaffold in developing spinal cord and consequential proper position of boundary cap cells. J Neurosci 35, 9211-9224.
Mita, S., de Monasterio-Schrader, P., Fünfschilling, U., Kawasaki, T., Mizuno, H., Iwasato, T., Nave, K.A., Werner, H.B., and Hirata, T. (2015). Transcallosal projections require glycoprotein M6-Dependent neurite growth and guidance. Cereb Cortex 25, 4111-4125.