This study was supported by Grant-in-Aid for Scientific Research from the Ministry of Education, Science and Culture of Japan (project Nos. 09260204 and 06454711) and Human Frontier Science Program.
Reorganization of Locomotor Activity during Development in the Prenatal Rata
Article first published online: 7 FEB 2006
Annals of the New York Academy of Sciences
Volume 860, NEURONAL MECHANISMS FOR GENERATING LOCOMOTOR ACTIVITY pages 306–317, November 1998
How to Cite
KUDO, N. and NISHIMARU, H. (1998), Reorganization of Locomotor Activity during Development in the Prenatal Rata. Annals of the New York Academy of Sciences, 860: 306–317. doi: 10.1111/j.1749-6632.1998.tb09058.x
- Issue published online: 7 FEB 2006
- Article first published online: 7 FEB 2006
Abstract: Development of neuronal circuits generating locomotor activity was studied using an isolated lumbar spinal cord preparation from fetal and neonatal rats. Bath application of N-methyl-d-aspartate (NMDA) or 5-HT evoked patterned motor activity resembling that seen during normal fictive locomotion on embryonic day (E) 20.5. Glycine-mediated inhibition was essential to the formation of this coordinated motor activity. In preparations from fetuses at the earlier stages (E14.5-E16.5), we observed spontaneous motoneuronal activity and chemically induced rhythmic bursts, which were synchronized on the two sides in the corresponding ventral roots. The spontaneous activity was not blocked by kynurenate, the glutamate receptor blocker, although it was completely abolished by strychnine, the glycine receptor antagonist. A brief application of glycine evoked excitatory responses resembling the spontaneous bursts in both time course and amplitude. It is concluded that glycine functions transiently as excitatory transmitters at these stages. These results suggest that functional change in glycine-induced responses during development plays an important role in differentiation of the neuronal circuits generating locomotion.