The Function of NMDA Receptors is Essential for the Development of Somatosensory Cortex Laboratory for Behavioral Genetics Laboratory for Neuronal Circuit Dynamics The Laboratory for Behavioral Genetics (Head, Dr. Shigeyoshi Itohara) and the Laboratory for Neuronal Circuit Dynamics (Head, Dr.Thomas Kn嗔fel) worked in collaboration with Louisiana State Universityand Massachusetts Institute of Technology (both located in the U.S.) and revealed that NMDA receptors serve a significant function in the development of somatosensory cortex. Layer IV neurons in the mouse somatosensory cortex aggregate according to the input patterns from whiskers during the first postnal week , thereby forming a characteristic configuration called barrels. Attention has been focused on the formation of barrels as an excellent model system that can help explain the fundamental principles in the development of mammalian cerebral cortex. However, restrictions on lab techniques have hindered the progress of research during this formation. In this study, a new DNA recombination system called Cre/loxP was applied to a method of knocking out target genes only at the excitatory cortical neurons of mice. Then, this new method was used to knockout a gene for the essential submit of NMDA receptorsﾐﾐspecifically in the cortex. Analysis of these mice showed that no barrels were formed even in adulthood, revealing the role of NMDA receptors in barrel formation. It is expected that this result, together with the newly introduced method, will offer clues to understanding how the cerebral cortices of mammals, including human beings, develop after birthﾐﾐin molecular level. magnified scene by clicking image Cortex-restricted NMDAR1 knockout using Cre/loxP system Iwasato, T., Datwani, A., Wolf, A. M., Nishiyama, H., Taguchi, Y., Tonegawa, S., Kn嗔fel, T., Erzurumulu, R. S., Itohara, S. Cortex-restricted disruption of NMDAR1 impairs neuronal patterns in the barrel cortex Nature Vol. 406, 17, pp726-731, August (2000)