RT Journal Article
SR Electronic
T1 Spinal motoneuron firing properties mature from rostral to caudal during post-natal development of the mouse
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2020.05.15.097436
DO 10.1101/2020.05.15.097436
A1 Calvin C. Smith
A1 Robert M. Brownstone
YR 2020
UL http://biorxiv.org/content/early/2020/05/16/2020.05.15.097436.abstract
AB Altricial mammals are born with immature nervous systems comprised of circuits that do not yet have the neuronal properties and connectivity required to produce future behaviours. During the critical period of post-natal development, neuronal properties are tuned to participate in functional circuits. In rodents, cervical motoneurons are born prior to lumbar motoneurons, and spinal cord development follows a sequential rostro-caudal sequence. Here we asked whether birth order is reflected in the post-natal development of electrophysiological properties. We show that motoneurons of both segments have similar properties at birth and follow the same developmental profile, with maximal firing increasing and excitability decreasing into the 3rd post-natal week. However, these maturative processes occur in cervical prior to lumbar motoneurons, correlating to the timing of arrival of descending systems. These results suggest that motoneuron properties do not mature by cell autonomous mechanisms alone, but rather depend on developing descending and spinal circuits.Competing Interest StatementThe authors have declared no competing interest.