Laboratory for Cortical Circuit Plasticity

Neuronal circuits in the brain are not rigidly fixed, but can be altered by neuronal activities. This use-dependent plasticity of circuits may be a neuronal basis of higher brain functions such as learning and memory. In this research team, we attempt to elucidate mechanisms underlying such experience-dependent plasticity of neuronal circuits in the cerebral cortex. The developing visual cortex is one of the cortical regions, in which such activity-dependent plasticity of neuronal circuits has extensively been studied since the following Hubel and Wiesel's original findings: Monocular visual deprivation in kittens induces functional changes in binocular visual responses of neurons and morphological changes in ocular dominance columns in the visual cortex. In this context the questions that we are addressing in this research team are as follows.

1. What is a functional role of each of GABAergic inhibitory neurons and glutamatergic excitatory neurons in the experience-dependent plasticity of neuronal circuits in the developing visual cortex? For this objective, we take advantage of various transgenic mice in which GABAergic neurons are marked with fluorescence protein and combine electrophysiology with in vivo two-photon functional calcium imaging of neuronal activities.
2. In the previous studies we found that brain-derived neurotrophic factor (BDNF) play a role in the induction of long-term potentiation (LTP) and endocannabinoids (eCBs) are involved in the induction of long-term depression (LTD) in the developing visual cortex. So, questions are: what molecular mechanisms are involved in experience-dependent plasticity of synaptic function in visual cortex?

Research Subjects

• Elucidation of mechanisms underlying long-term potentiation/depression in developing visual cortex
• Analysis of input-dependent changes in visual cortical neurons by long-lasting functional imaging
• Difference in response selectivity between inhibitory and excitaotry neurons in visual cortex
• Visual response properties of each subtype of GABAergic neurons in visual cortex
• Difference in plasticity between inhibitory and excitatory neurons in developing visual cortex

Publications

1. Sarihi A, Mirnajafi-Zadeh J, Jiang B, Sohya K, Safari M-S, Arami M, Yanagawa,Tsumoto T.:
   "Cell type-specific, presynaptic LTP of inhibitory synapses on fast-spiking GABAergic neurons in the mouse visual cortex."
   Journal of Neuroscience., 32, 13189-13199. 2012
2. Takahashi H, Katayama K, Sohya K, Miyamoto H, Prasad T, Matsumoto Y, Ota M, Yasuda H, Tsumoto T, Aruga J, Craig AM.:
   "Selective contorol of inhibitory syanapse development by Slitrk3-PTPδ trans-synaptic interaction."
   Nature Neuroscie., 15, 389-398, 2012
3. Jiang, B., Huang, S., de Pasquale, R., Millman, D., Song, L., Mackey, K., Lee, H.-K., Tsumoto, T*. and Kirkwood, A*. (*, co-corresponding authors):
   "The maturation of GABAergic transmission in visual cortex requires endocannabinoid-mediated LTD of inhibitory inputs during a critical period."
   Neuron, 66, 248-259. 2010
4. Jiang B, Sohya K, Sarihi S, Yanagawa Y, Tsumoto T.:
   "Laminar-specific maturation of GABAergic transmission and susceptibility to visual deprivation are related to endocannabinoid sensitivity in mouse visual cortex."
   Journal of Neuroscience, 30, 14261-14272. 2010
5. Kameyama, K., Sohya, K., Ebina, T., Fukuda, A., Yanagawa, Y. and Tsumoto, T.:
   "Difference in binocularity and ocular dominance plasticity between GABAergic and excitatory cortical neurons."
   Journal of Neuroscience, 30: 1551-1559, 2010
6. Hama, Y., Shiraki, K., Yoshida, Y., Maruyama, A., Yasuda, M., Tsuda, M., Honda, M., Takahashi, M., Higuchi, H., Takasaki, I., Daikoku, T., and Tsumoto, T.:
   "Antibody to varicella-zoster immediate early 62 augments allodynia in zoster via brain-derived neurotrophic factor."
   Journal of Virology, 84: 1616-1624, 2010
7. Huang, Y., Yasuda, H., Sarihi, A. and Tsumoto, T.:
   "Roles of endocannabinoids in heterosynaptic long-term depression of excitatory synaptic transmission in visual cortex of young mice."
   Journal of Neuroscience, 28: 7074 - 7083, 2008
8. Yasuda, H., Huang, Y. and Tsumoto, T.:
   "Regulation of excitability and plasticity by endocannabinoids and PKA in developing hippocampus"
   Proceeding of the National Academy of Sciences USA, 105, 3106-3111, 2008
9. Sarihi, A., Jiang, B., Komaki, A., Sohya, K., Yanagawa, Y. and Tsumoto, T.:
   "Metabotropic glutamate receptor type5-dependent long-term potentiation of excitatory synapses on fast-spiking GABAergic neurons in mouse visual corte"
   Journal of Neuroscience, 28, 1224-1235, 2008
10. Kohara, K., Yasuda, H., Huang, Y., Adachi, N., Sohya, K. and Tsumoto, T.:
    "A local reduction in cortical GABAergic synapses after a loss of endogenous brain-derived neurotrophic factor, as revealed by single-cell gene knock-out method"
    Journal of Neuroscience, 27, 7234-7244, 2007