To understand development of complex yet sophisticated neuronal circuits underlying higher brain function of mammals, integrative studies which cover from molecules to whole animals are indispensable. By using a wide range of techniques, such as mouse genetics (gene knockout), 2-photon microscopy, confocal microscopy, histology and behavioral analyses, we are studying mechanisms of development and function of mammalian neuronal circuits. In particular, we are interested in activitydependent circuit development during postnatal stages.
A process of neuronal circuit development in the neonatal brain was observed using two-photon microscopy. Dendrites of cortical neurons (red) were highly motile and expanded towards proper presynaptic targets (thalamocortical axons: green). Images of a single neuron in the mouse somatosensory cortex at 0h, 4.5h, 9h and 18h after postnatal day 5 are shown.
Luo, W., Mizuno, H., Iwata, R., Nakazawa, S., Yasuda, K., Itohara, S., and Iwasato, T. (2016). Supernova: A versatile vector system for single-cell labeling and gene function studies in vivo. Sci Rep 6, 35747.
Iwata, R., Matsukawa, H., Yasuda, K., Mizuno, H., Itohara, S., and Iwasato, T. (2015). Developmental RacGAP α2-chimaerin signaling is a determinant of the morphological features of dendritic spines in adulthood. J Neurosci 35, 13728-13744.
Mizuno, H., Luo, W., Tarusawa, E., Saito, Y.M., Sato, T., Yoshimura, Y., Itohara, S., and Iwasato, T. (2014). NMDAR-regulated dynamics of layer 4 neuronal dendrites during thalamocortical reorganization in neonates. Neuron 82, 365-379.