Ventral horn motoneurons 10, 20 and 52 weeks after T-9 spinal cord transection

doi:10.1016/0361-9230(92)90230-U

Brain Research Bulletin

Volume 28, Issue 1, January 1992, Pages 57-60

https://doi.org/10.1016/0361-9230(92)90230-U Get rights and content

Abstract

To determine if transneuronal degeneration occurs in ventral horn motoneurons caudal to a spinal cord transection, we completely transected the spinal cord at T-9 in seven-week-old female rats. Ten, 20 or 52 weeks later, the motoneurons of the right sciatic nerve of transected and control rats were retrogradely labeled with Fluoro-Gold. There were no differences between control and transected rats in numbers or rostrocaudal distribution of labeled motoneurons at either 10, 20 or 52 weeks. At 20 weeks, there was no significant difference between control and transected rats in mean cross-sectional area of labeled neurons. We conclude that transneuronal degeneration did not occur.

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While some of the disparities observed across studies are likely related to differences in injury type and/or severity, the methods used to evaluate motor neuron survival may also contribute. Indeed, methods used to assess neuronal survival post-injury vary considerably across studies, ranging from retrograde tracing methods (fluoro‑gold, horseradish peroxidase, CtB) to immunohistochemistry/staining methods such as hematoxaline and eosin, Cresyl violet, TUNEL, ChAT, etc. (Bose et al., 2005; Eidelberg et al., 1989; Grossman et al., 2001; McBride and Feringa, 1992; Nicaise et al., 2013; Nicaise et al., 2012a; Nicaise et al., 2012b; Satkunendrarajah et al., 2016; Yokota et al., 2019). Although immunohistochemical methods enable a broader view of injury-associated changes post-injury (e.g. regional/segmental assessments), they are limited by a lack of specificity to defined cell populations and by their susceptibility to injury-associated changes that do not necessarily correlate with cell loss.
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Despite the adaptation in skeletal muscles to decreased neuromuscular activity and loading levels, the number, cell body size, and oxidative enzyme activity of spinal motoneurons innervating skeletal muscles in adult rats remain stable following hindlimb unloading (Ishihara et al., 1997, 2004). Lack of adaptation in spinal motoneurons to chronic decrease of the neuromuscular activity and loading levels (e.g., spinal cord transection and spinal cord isolation) has been also reported (Donselaar et al., 1986; McBride and Feringa, 1992; Bjugn et al., 1997; Roy et al., 2007). There were no changes in the cell body size or oxidative enzyme activity of motoneurons after spinal cord transaction at a low thoracic and a high sacral level plus bilateral deafferentation between the two transaction sites in cats (Chalmers et al., 1992) or after muscle inactivity in rats induced by chronic tetrodotoxin administration (Seburn et al., 1994).
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Citation Excerpt :
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ArticleVentral horn motoneurons 10, 20 and 52 weeks after T-9 spinal cord transection

Abstract

Brain Res. Bull.

J. Neurol. Sci.

Exp. Neurol.

Exp. Neurol.

Exp. Neurol.

Brain Res.

Exp. Neurol.

Exp. Neurol.

Exp. Neurol.

A quantitative study of certain morphological changes in spinal motor neurons during axon reaction

J. Comp. Neurol.

Structural changes in anterior horn cells following central lesions

Projections and termination of the corticospinal tract in rodents

Exp. Brain Res.

Rubrospinal projections in the rat

J. Comp. Neurol.

Denervation in hemiplegic muscles

Stroke

Control of the motor cortex of spinal motoneurones in man

Hemiplegic amyotrophy

Arch. Neurol.

Article
Ventral horn motoneurons 10, 20 and 52 weeks after T-9 spinal cord transection