New Haven, Conn.--Release of the neurotransmitter GABA by adultneuronal precursor cells that develop into neurons limits stem cellproliferation, according to a study at Yale School of Medicine in theSeptember issue of Nature Neuroscience.
Tight regulation of new cell growth in the adult brain is criticalsince uncontrolled proliferation can lead to devastating diseases, suchas cancer.
"The GABAergic signaling described in our paper allows aproper balance between stem cells and daughter cells, and preventsout-of-control proliferation of stem cells," said Angelique Bordey,assistant professor in the Departments of Neurosurgery and Cellular& Molecular Physiology, and senior author of the study. "The nextquestion we would like to answer is what would happen if this signalingwas disrupted in a living being."
Neural stem cells in the subventricular zone of the brain arethought to give rise to glioma, or brain tumors, when theirproliferation is out of control, she said. "One of the goals of thisline of research is to find ways to promote neurogenesis in acontrolled manner, so identifying signaling pathways, factors andreceptors that block or promote neurogenesis is very important," Bordeysaid. "These factors and receptors provide additional sites forpharmaceutical targets to promote neurogenesis and self-renewal ofdying cells."
Alternatively, identifying negative GABAergic signaling onstem cell proliferation, as the researchers did in this study, suggeststhat any drugs that would enhance GABA's function may limitneurogenesis, she said.
"GABAergic drugs such as alcohol and benzodiazepines (somesleeping pills) have been used by a large number of individuals in oursociety and these drugs are expected to block stem cell proliferation,"Bordey said. "Such an impact of these drugs on neurogenesis and brainfunction would be the next step to investigate."
Co-authors include Xiuxin Liu and Qin Wang of Yale and Tarik Haydar of George Washington University School of Medicine.
Nature Neuroscience 8: 1179-1187 (September 2005)
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