Loss of pre-inspiratory neuron synchroneity in mice with DSCAM deficiency.
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 hours after birth. Whole body plethysmography showed irregular respiration and lower ventilatory response to hypercapnia in the null mutants. Further, 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 (Pre-I) neurons located in the rostral ventrolateral medulla (RVLM) 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. These results have been published (Amano et al. 2009).
Amano
Kenji
K
Laboratory for Neurogenetics, RIKEN Brain Science Institute, Saitama, Japan. kenjia@brain.riken.jp
Fujii
Morimitsu
M
Arata
Satoru
S
Ogawa
Masaharu
M
Yamakawa
Kazuhiro
K
Arata
Akiko
A
D000818:Animals; D000831:Animals, Newborn / Q000502:physiology; D001933:Brain Stem / Q000473:pathology / Q000503:physiopathology; D015815:Cell Adhesion Molecules / Q000172:deficiency* / Q000235:genetics; D001239:Inhalation / Q000502:physiology*; D051379:Mice; D009474:Neurons / Q000473:pathology*
D015815:Cell Adhesion Molecules; C491735:Dscam protein, mouse