Skip to main content
Log in

Delayed loss of spinal motoneurons after peripheral nerve injury in adult rats: a quantitative morphological study

  • Research Article
  • Published:
Experimental Brain Research Aims and scope Submit manuscript

Abstract.

The existence of retrograde cell death in sensory dorsal root ganglion (DRG) cells after peripheral nerve injury is well established. However, with respect to retrograde motoneuron death after peripheral nerve injury, available data are conflicting. This may partly be due to the cell counting techniques used. In the present study, quantitative morphometric methods have been used to analyse retrograde motoneuron death induced by spinal nerve injury in adult rats. For comparison, DRG cells were also included in the study. The C7 spinal nerve was transected about 10 mm distal to the DRG and exposed to the fluorescent tracer fast blue in order to retrogradely label the spinal motoneurons and DRG cells of the C7 segment. At 1–16 weeks postoperatively, the nuclei of fast-blue-labelled C7 motoneurons and DRG cells were counted in consecutive 50-µm-thick serial sections. For comparison, the physical disector technique and measurements of neuronal density were also used to calculate motoneuron number. The counts of fast-blue-labelled motoneurons revealed a delayed motoneuron loss amounting to 21% and 31% after 8 and 16 weeks, respectively (P<0.001). The remaining motoneurons exhibited 20% (P<0.05) soma atrophy. Using the physical disector technique, the motoneuron loss was 23% (P<0.001) after 16 weeks. Calculations of neuronal density in Nissl-stained sections failed to reveal any motoneuron loss, although after correction for shrinkage of the ventral horn a 14% (P<0.001) motoneuron loss was found. The fast-blue-labelled DRG neurons displayed 51% (P<0.001) cell loss after 16 weeks, and the remaining cells showed 22% (P<0.001) soma atrophy. In summary, cervical spinal nerve injury induces retrograde degeneration of both motoneurons and DRG cells. However, to demonstrate the motoneuron loss adequate techniques for cell counts have to be employed.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

Author information

Authors and Affiliations

Authors

Additional information

Electronic Publication

Rights and permissions

Reprints and permissions

About this article

Cite this article

Ma, J., Novikov, L.N., Wiberg, M. et al. Delayed loss of spinal motoneurons after peripheral nerve injury in adult rats: a quantitative morphological study. Exp Brain Res 139, 216–223 (2001). https://doi.org/10.1007/s002210100769

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s002210100769

Navigation