Graduate School of Medicine „ Human Science
„ Anatomy

Professor: Tetsuji MORIIZUMI
Senior Assistant Professor: Kohzo NAKAYAMA
Assistant Professor: Nanae FUKUSHIMA, Kyutaro KAWAGISHI

Summary of Activity
The purpose of our study is to clarify functional roles of the brain and the nervous system on a neuroanatomical basis. We have pursued our research mainly on cell dynamics of the neural stem cells (adult neurogensis), functionally essential neuronal population (minimum neuron number related to a specific function), and neural control of the suckling behavior. Quantification of the whole number of specific neurons is being estimated by reliable stereological techniques. Projects are also underway to reveal mechanism of spontaneous regeneration and regenerative capability of the damaged brain, particularly of the central olfactory tract.


Research Projects
The specific current research interests are as follows:
* Regenerative mechanism of the central olfactory tract
* Functional and morphological correlates of the olfactory nervous system
* Cell dynamics of the neural stem cells in the olfactory nervous system
* Determination of the functionally essential neuronal population in the nervous system
* Neural mechanism regulating breastfeeding
* Functional neural plasticity of newborn animals
* Neuroanatomical analysis of the human nervous system


Spontaneous regeneration the lateral olfactory tract (LOT). (A) An asterisk points to the neonatally transected site of the left LOT. After removal of the right olfactory bulb (OB) at the adult stage, this rat showed normal olfactory function to avoid a repellent by sniffing. (B) FB was injected just after the LOT transection at the neonatal stage. FG was injected at the adult stage. (C) FB (+) neurons cannot be seen in the left OB, indicating complete transection of the LOT. Only FG (+) neurons can be seen in the left OB (arrows), indicating spontaneous regeneration of the LOT.

References
  1. Sakamoto, M., Yokouchi, K., Sekiguchi, Y., Fukushima, N., Kawagishi, K., Kakegawa, A., Sumitomo, N., and Moriizumi, T. (2010) Re-evaluation of spontaneous regeneration of the lateral olfactory tract. Neurosci. Res. 68: 15-21.

  2. Kawagishi, K., Yokouchi, K., Fukushima, N., Sakamoto, M., Sumitomo, N., and Moriizumi, T. (2009) Determination of functionally essential neuronal population of the olfactory epithelium for nipple search and subsequent suckling behavior in newborn rats. Brain Res. 1276: 50-57.

  3. Kawagishi, K., Fukushima, N., Yokouchi, K., Sumitomo, N., Kakegawa, A., and Moriizumi, T. (2008) Tyrosine hydroxylase-immunoreactive fibers in human vagus nerve. J. Clin. Neurosci. 15: 1023-1026.

  4. Fukushima, N., Yokouchi, K., Kawagishi, K., Kakegawa, A., Ezawa, N., and Moriizumi, T. (2007) Neural plasticity of neonatal hypoglossal nerve for effective suckling. J. Neurosci. Res. 85: 2518-2526.

  5. Yokouchi, K., Fukushima, N., Kakegawa, A., Kawagishi, K., Fukuyama, T., and Moriizumi, T. (2007) Functional role of lingual nerve in breastfeeding. Int. J. Dev. Neurosci. 25: 115-119.

  6. Kakegawa, A., Yokouchi, K., Fukushima, N., Fukuyama, T., and Moriizumi, T. (2006) Motor neurons essential for normal sciatic function in neonatally nerve-injured rats. Neuroreport 17: 1149-1152.

  7. Fukuyama, T., Yokouchi, K., Fukushima, N., Kawagishi, K., Kakegawa, A., and Moriizumi, T. (2006) Differential effects of hypoglossal and facial nerve injuries on survival and growth of rats at different developmental stages. Int. J. Dev. Neurosci. 24: 307-317.

  8. Fujita, K., Yokouchi, K., Fukuyama, T., Fukushima, N., Kawagishi, K., and Moriizumi, T. (2006) Effects of hypoglossal and facial nerve injuries on milk-suckling. Int. J. Dev. Neurosci. 24: 29-34.

  9. Fukushima, N., Yokouchi, K., Kawagishi, K., and Moriizumi, T. (2006) Effect of maternal deprivation on milk intake in normal and bilaterally facial nerve-injured developing rats. Neurosci. Res. 54: 154-157.

  10. Higashiyama, H., Fukushima, N., Yokouchi, K., Kawagishi, K., and Moriizumi, T. (2005) The minimum number of facial motor neurons essential for minimal whisker movement in neonatally nerve-transected young adult rats. J. Neurosurg. 102: 390-395.