Electrical maturation of spinal neurons in the human fetus: comparison of ventral and dorsal horn

Tadros, M. A., Lim, R., Hughes, D. I. , Brichta, A. M. and Callister, R. J. (2015) Electrical maturation of spinal neurons in the human fetus: comparison of ventral and dorsal horn. Journal of Neurophysiology, 114(5), pp. 2661-2671. (doi: 10.1152/jn.00682.2015) (PMID:26334015)

Abstract

The spinal cord is critical for modifying and relaying sensory information to, and motor commands from, higher centres in the central nervous system to initiate and maintain contextually relevant locomotor responses. Our understanding of how spinal sensorimotor circuits are established during in utero development is based largely on studies in rodents. In contrast, there is little functional data on the development of sensory and motor systems in humans. Here, we use patch clamp electrophysiology to examine the development of neuronal excitability in human fetal spinal cords (10-18 weeks gestation; WG). Transverse spinal cord slices (300 µm thick) were prepared and recordings were made from visualized neurons in either the ventral (VH) or dorsal (DH) horn at 32oC. Action potentials (APs) could be elicited in VH neurons throughout the period examined, but only after 16 WG in DH neurons. At this age, VH neurons discharged multiple APs, whereas most DH neurons discharged single APs. In addition, at 16-18 WG VH neurons also displayed larger AP and after-hyperpolarization amplitudes than DH neurons. Between 10 and 18 WG the intrinsic properties of VH neurons changed markedly, with input resistance decreasing and AP and AHP amplitudes increasing. These findings are consistent with the hypothesis that VH motor circuitry matures more rapidly than the DH circuits that are involved in processing tactile and nociceptive information.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Hughes, Dr David I
• Authors: Tadros, M. A., Lim, R., Hughes, D. I., Brichta, A. M., and Callister, R. J.
• College/School: College of Medical Veterinary and Life Sciences > School of Psychology & Neuroscience
• Journal Name: Journal of Neurophysiology
• Publisher: American Physiological Society
• ISSN: 0022-3077
• ISSN (Online): 1522-1598
• Copyright Holders: Copyright © 2015 American Physiological Society
• First Published: First published in Journal of Neurophysiology 114(5):2661-2671
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher.