PT  - JOURNAL ARTICLE
AU  - Natalia Peunova
AU  - Vladimir Scheinker
AU  - Hollis Cline
AU  - Grigori Enikolopov
TI  - Nitric Oxide Is an Essential Negative Regulator of Cell Proliferation in <em>Xenopus</em> Brain
AID  - 10.1523/JNEUROSCI.21-22-08809.2001
DP  - 2001 Nov 15
TA  - The Journal of Neuroscience
PG  - 8809--8818
VI  - 21
IP  - 22
4099  - http://www.jneurosci.org/content/21/22/8809.short
4100  - http://www.jneurosci.org/content/21/22/8809.full
SO  - J. Neurosci.2001 Nov 15; 21
AB  - Mechanisms controlling the transition of a neural precursor cell from proliferation to differentiation during brain development determine the distinct anatomical features of the brain. Nitric oxide (NO) may mediate such a transition, because it can suppress DNA synthesis and cell proliferation. We cloned the gene encoding the neuronal isoform of Xenopus NO synthase (XNOS) and found that in the developing brain of Xenopus tadpoles, a zone of XNOS-expressing cells lies adjacent to the zone of dividing neuronal precursors. Exogenous NO, supplied to the tadpole brain in vivo, decreased the number of proliferating cells and the total number of cells in the optic tectum. Conversely, inhibition of NOS activity in vivo increased the number of proliferating cells and the total number of cells in the optic tectum. NOS inhibition yielded larger brains with grossly perturbed organization. Our results indicate that NO is an essential negative regulator of neuronal precursor proliferation during vertebrate brain development.