The Journal of Neuroscience, March 4, 2009, 29(9):2984-2996; doi:10.1523/JNEUROSCI.3624-08.2009
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Behavioral/Systems/Cognitive
DSCAM Deficiency Causes Loss of Pre-Inspiratory Neuron Synchroneity and Perinatal Death
Kenji Amano,1
Morimitsu Fujii,2
Satoru Arata,7
Takuro Tojima,3
Masaharu Ogawa,4
Noriyuki Morita,5
Atsushi Shimohata,1
Teiichi Furuichi,5
Shigeyoshi Itohara,6
Hiroyuki Kamiguchi,3
Julie R. Korenberg,8
Akiko Arata,2,9 and
Kazuhiro Yamakawa1
Laboratories for 1Neurogenetics, 2Memory and Learning, 3Neuronal Growth Mechanisms, 4Cell Culture Development, 5Molecular Neurogenesis, and 6Behavioral Genetics, RIKEN Brain Science Institute, Wako-shi, Saitama 351-0198, Japan, 7Center for Biotechnology, Showa University, Shinagawa-ku, Tokyo 142-8555, Japan, 8The Brain Institute, University of Utah, Salt Lake City, Utah 84108, and 9Division of Physiome, Department of Physiology, Hyogo College of Medicine, Nishinomiya, Hyogo 663-8501, Japan
Correspondence should be addressed to either of the following: Dr. Kazuhiro Yamakawa, Laboratory for Neurogenetics, RIKEN Brain Science Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan, Email: yamakawa{at}brain.riken.jp; or Dr. Akiko Arata, Division of Physiome, Department of Physiology, Hyogo College of Medicine, 1-1 Mukogawa, Nishinomiya, Hyogo 663-8501, Japan, Email: akoarata{at}hyo-med.ac.jp or Email: ako{at}brain.riken.jp
Down syndrome cell adhesion molecule (DSCAM) is a neural adhesion molecule that plays diverse roles in neural development. We disrupted the Dscam locus in mice and found that the null mutants (Dscam–/–) died within 24 h after birth. Whole-body plethysmography showed irregular respiration and lower ventilatory response to hypercapnia in the null mutants. Furthermore, a medulla–spinal cord preparation of Dscam–/– mice showed that the C4 ventral root activity, which drives diaphragm contraction for inspiration, had an irregular rhythm with frequent apneas. Optical imaging of the preparation using voltage-sensitive dye revealed that the pre-inspiratory neurons located in the rostral ventrolateral medulla and belonging to the rhythm generator for respiration, lost their synchroneity in Dscam–/– mice. Dscam+/– mice, which survived to adulthood without any overt abnormalities, also showed irregular respiration but milder than Dscam–/– mice. These results suggest that DSCAM plays a critical role in central respiratory regulation in a dosage-dependent manner.
Received July 31, 2008;
revised Jan. 15, 2009;
accepted Jan. 17, 2009.
Correspondence should be addressed to either of the following: Dr. Kazuhiro Yamakawa, Laboratory for Neurogenetics, RIKEN Brain Science Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan, Email: yamakawa{at}brain.riken.jp; or Dr. Akiko Arata, Division of Physiome, Department of Physiology, Hyogo College of Medicine, 1-1 Mukogawa, Nishinomiya, Hyogo 663-8501, Japan, Email: akoarata{at}hyo-med.ac.jp or Email: ako{at}brain.riken.jp