Division of Cell Biology and Neuroscience, Department of Morphological and Physiological Sciences

<BODY> <P><IMG src="overview.gif" width="168" height="55" border="0"></P> <P><SPAN lang="EN-US" style='font-size:10.0pt;font-family: "New York";mso-fareast-font-family:Osaka;mso-bidi-font-family:"Times New Roman"; color:gray;mso-font-kerning:1.0pt;mso-ansi-language:EN-US;mso-fareast-language: JA;mso-bidi-language:AR-SA'><FONT color="#999999" size="3" face="News Gothic MT">EARCH THEMES IN OUR LABORATORY</FONT></SPAN></P> <P class="MsoNormal"><B>Molecular mechanisms of cortical development</B>: How does the neocortex develop? To address this question (and look for the ways to repair the damaged brain), we have been studying the development of the brain, focusing on the phenomenon happening in the ventricular zone (germinal zone, neuroepithelium) of the neocortex. Most cortical neurons are born in the ventricular zone, differentiate, migrate out of the ventricular zone, then form the neocortex. We have cloned several novel molecules expressed in the ventricular zone and tried to elucidate functions of these molecules in order to reveal the mechanisms serving for differentiation of neurons, layer fate decisions and regulation of the migration start.</P> <BLOCKQUOTE>Recently we cloned novel molecules (we call 'FILIP') of which mRNAs are located in the ventricular zone. FILIP regulates cortical neurons out of the ventricular zone by inducing the degradation of actin-binding protein, Filamin A (Nagano, T. et al., Nature Cell Biology). When to start migration is essential to form 6 layers, typical feature of neocortex, and FILIP is a key molecule controlling this process. Details will be introduced in highlight section of <I>'Nature Reviews, Molecular Cell Biology, July issue, 2002'.</I> We are now studying on the regulatory mechanisms of FILIP and Filamin A.</BLOCKQUOTE> <P class="MsoNormal"><B>Molecular mechanisms of maturation of neuronal circuits</B>: Pyramidal tracts are good examples for studying the maturation of neuronal circuits. Adult pattern of pyramidal tracts projections is established through collateral branching and pruning from immature form of projections. We would like to address for the molecular bases of this maturation process.</P> <P><B>Functions of TBPIP</B>: TBPIP is a novel molecule that we cloned several years ago. TBPIP could enhance the function of TBP-1 of 26S proteasome and the activities of nuclear receptors. Also, its robust expression in the testis along with other data suggests that TBPIP is involved in meiosis. We are pursuing the precise molecular mechanisms underlying these apparent distinct functions of TBPIP by several approaches<BR> </P> </BODY>