Dividing glial cells maintain differentiated properties including complex morphology and functional synapses

doi:10.1073/pnas.0811353106

Dividing glial cells maintain differentiated properties including complex morphology and functional synapses

^aHoward Hughes Medical Institute and Departments of Physiology and Biochemistry, University of California, San Francisco, CA 94158; and
^bBritton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China.

Contributed by Yuh Nung Jan, November 8, 2008 (received for review October 13, 2008)

Abstract

It is generally believed that dividing cells gain complex features of differentiation only after exiting the cell cycle because cell division and differentiation are both under such tight regulation that their coexistence is deemed unlikely. As the major proliferating cell type in the mammalian CNS, NG2 glial cells (NG2 cells) account for 5–8% of the glial cell population and form synaptic contacts with neurons. Here we report that NG2 cells divide while maintaining their differentiation, including morphological features, such as the elaboration of multiple complex cellular processes and physiological features including active glutamatergic and GABAergic synaptic responses. Not only do NG2 cells continue to receive excitatory and inhibitory synaptic inputs as they undergo mitosis, a subpopulation of dividing NG2 cells can fire action potentials upon depolarization, thereby revealing that these dividing NG2 cells retain voltage-gated ion channels as well as transmitter receptors for signal processing. These findings provide a clear counterexample of the widely perceived incompatibility between cell division and differentiation.

Footnotes

¹To whom correspondence should be addressed. E-mail: yuhnung.jan{at}ucsf.edu
Author contributions: W.-P.G. designed research; W.-P.G. and W.Z. performed research; W.-P.G., W.Z., and Q.L. analyzed data; and W.-P.G., L.Y.J., and Y.N.J. wrote the paper.
The authors declare no conflict of interest.
This article contains supporting information online at www.pnas.org/cgi/content/full/0811353106/DCSupplemental.
Freely available online through the PNAS open access option.