The fine motor skills such as dexterous hand movements are specifically developed in higher primates including humans. The Dexterous hand movements (Movie 1) have given humans the ability to manipulate small objects and a skill enabling complex behaviors such as writing and drawing. The cells of motor cortex in these species descend to the spinal cord through the corticospinal tract (CST) and are directly connect to the spinal motoneurons. It is assumed that the corticospinal tract, especially the direct cortico-motoneuronal (CM) pathway, plays a major role in the dexterous hand movements. Recent studies from our laboratory, however, demonstrated that the indirect pathways through the spinal cord interneurons such as propriospinal neurons or segmental interneurons could partly contribute to the control of dexterous hand movements using pathway-selective and reversible technique (double-infection technique) for blocking neural transmission. Now we think it is necessary to study how much the direct CM pathway contributes to the control of dexterous hand movements by using more recently developed sophisticated techniques. If the direct CM pathway is essential for the dexterous hand movements, the macaque monkeys which lack the CM pathway would not develop the ability of dexterous hand movements. In ASHBi, we will generate the macaque monkeys in which the CM pathway is lacking by genome editing technology, and follow the development of dexterous hand movements in these animals.
Reona Yamaguchi obtained his PhD from Kagoshima University (2016) and move to University of Washington as a postdoc (2016-2017). After that, he moved to Kyoto University as an assistant professor. He was appointed assistant professor in 2019 in ASHBi of Kyoto University.
Okamura JY, Oshima J, Yamaguchi R, Yamashita W, Wang G. An intrinsic algorithm for viewing angle tolerance of object discrimination in human subjects. Can J Exp Psychol. 2020;74(1):73‐82. doi:10.1037/cep0000188
Isa T, Mitsuhashi M, Yamaguchi R. Alternative routes for recovery of hand functions after corticospinal tract injury in primates and rodents. Curr Opin Neurol. 2019;32(6):836‐843. doi:10.1097/WCO.0000000000000749
Yamaguchi R, Sakamoto A, Yamaguchi R, et al. Di-(2-Ethylhexyl) Phthalate Promotes Release of Tissue Factor-Bearing Microparticles From Macrophages via the TGFβ1/Smad/PAI-1 Signaling Pathway. Am J Med Sci. 2019;357(6):492‐506. doi:10.1016/j.amjms.2019.02.012
Yamaguchi R, Sakamoto A, Yamaguchi R, et al. Transcription factor specificity protein 1 modulates TGFβ1/Smad signaling to negatively regulate SIGIRR expression by human M1 macrophages stimulated with substance P. Cytokine. 2018;108:24‐36. doi:10.1016/j.cyto.2018.03.011
Sakamoto A, Yamaguchi R, Yamaguchi R, Narahara S, Sugiuchi H, Yamaguchi Y. Cross-talk between the transcription factor Sp1 and C/EBPβ modulates TGFβ1 production to negatively regulate the expression of chemokine RANTES. Heliyon. 2018;4(7):e00679. Published 2018 Jul 4. doi:10.1016/j.heliyon.2018.e00679
Yamaguchi R, Okamura JY, Wang G. Dynamics of population coding for object views following object discrimination training. Neuroscience. 2016;330:109‐120. doi:10.1016/j.neuroscience.2016.05.039
Yamaguchi R, Okamura J, Honda K, Oshima J, Saruwatari S, Wang G, The Responses of cell population in the inferotemporal cortex to object views with the experience of association learning (in Japanese), The transactions of the Institute of Electrical Engineers of Japan. C, A publication of Electronics, Information and Systems Society. 2016;136:109-120.
Okamura JY, Yamaguchi R, Honda K, Wang G, Tanaka K. Neural substrates of view-invariant object recognition developed without experiencing rotations of the objects. J Neurosci. 2014;34(45):15047‐15059. doi:10.1523/JNEUROSCI.1898-14.2014
Yamaguchi R, Honda K, Okamura J, Saruwatari S, Oshima J, Wang G. Dynamics of Neuronal Responses in the Inferotemporal Cortex Associated with 3D Object Recognition Learning, International Conference on Neural Information Processing, 2013;193-199.
Yamaguchi R, Honda K, Ikejiri Y, Okamura J, Wang G, Responses of the inferotemporal neurons to the views of the 3D objects with long term visual experience (in Japanese), Japanese Society for Medical and Biological Engineering. 2013;51:45-50.