The Journal of Neuroscience, April 9, 2008, 28(15):4037-4046; doi:10.1523/JNEUROSCI.4126-07.2008
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Development/Plasticity/Repair
Tlx1 and Tlx3 Coordinate Specification of Dorsal Horn Pain-Modulatory Peptidergic Neurons
Yi Xu,1
Claudia Lopes,1,2
Ying Qian,1
Ying Liu,3
Leping Cheng,4
Martyn Goulding,5
Eric E. Turner,3
Deolinda Lima,2 and
Qiufu Ma1
1Dana-Farber Cancer Institute and Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115, 2Laboratory of Molecular Cell Biology, University of Porto, Porto, Portugal, 3Department of Psychiatry, University of California, San Diego and Veterans Affairs San Diego Healthcare System, La Jolla, California 92093-0603, 4Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China, and 5Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, California 92037
Correspondence should be addressed to Qiufu Ma, Dana-Farber Cancer Institute and Department of Neurobiology, Harvard Medical School, 1 Jimmy Fund Way, Boston, MA 02115. Email: Qiufu_Ma{at}dfci.harvard.edu
The dorsal spinal cord synthesizes a variety of neuropeptides that modulate the transmission of nociceptive sensory information. Here, we used genetic fate mapping to show that Tlx3+ spinal cord neurons and their derivatives represent a heterogeneous population of neurons, marked by partially overlapping expression of a set of neuropeptide genes, including those encoding the anti-opioid peptide cholecystokinin, pronociceptive Substance P (SP), Neurokinin B, and a late wave of somatostatin. Mutations of Tlx3 and Tlx1 result in a loss of expression of these peptide genes. Brn3a, a homeobox transcription factor, the expression of which is partly dependent on Tlx3, is required specifically for the early wave of SP expression. These studies suggest that Tlx1 and Tlx3 operate high in the regulatory hierarchy that coordinates specification of dorsal horn pain-modulatory peptidergic neurons.
Key words: dorsal spinal cord; peptidergic neurons; Tlx3; cell fate specification; transcriptional regulation; pain
Received Sept. 9, 2007;
revised Jan. 29, 2008;
accepted Feb. 23, 2008.
Correspondence should be addressed to Qiufu Ma, Dana-Farber Cancer Institute and Department of Neurobiology, Harvard Medical School, 1 Jimmy Fund Way, Boston, MA 02115. Email: Qiufu_Ma{at}dfci.harvard.edu