Use of laser microdissection in the investigation of facial motoneuron and neuropil molecular phenotypes after peripheral axotomy

Nichole A. Mesnard, Thomas D. Alexander, Virginia M. Sanders, Kathryn Jones

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

The mechanism underlying axotomy-induced motoneuron loss is not fully understood, but appears to involve molecular changes within the injured motoneuron and the surrounding local microenvironment (neuropil). The mouse facial nucleus consists of six subnuclei which respond differentially to facial nerve transection at the stylomastoid foramen. The ventromedial (VM) subnucleus maintains virtually full facial motoneuron (FMN) survival following axotomy, whereas the ventrolateral (VL) subnucleus results in significant FMN loss with the same nerve injury. We hypothesized that distinct molecular phenotypes of FMN existed within the two subregions, one responsible for maintaining cell survival and the other promoting cell death. In this study, we used laser microdissection to isolate VM and VL facial subnuclear regions for molecular characterization. We discovered that, regardless of neuronal fate after injury, FMN in either subnuclear region respond vigorously to injury with a characteristic "regenerative" profile and additionally, the surviving VL FMN appear to compensate for the significant FMN loss. In contrast, significant differences in the expression of pro-inflammatory cytokine mRNA in the surrounding neuropil response were found between the two subnuclear regions of the facial nucleus that support a causative role for glial and/or immune-derived molecules in directing the contrasting responses of the FMN to axonal transection.

Original languageEnglish (US)
Pages (from-to)94-103
Number of pages10
JournalExperimental Neurology
Volume225
Issue number1
DOIs
StatePublished - Sep 2010
Externally publishedYes

Fingerprint

Axotomy
Microdissection
Neuropil
Motor Neurons
Lasers
Phenotype
Facial Injuries
Facial Nerve
Wounds and Injuries
Neuroglia
Cell Survival
Cell Death
Cytokines
Messenger RNA

Keywords

  • Facial motor nucleus
  • Facial nerve axotomy
  • Motoneuron
  • Neuropil
  • Subnuclei

ASJC Scopus subject areas

  • Neurology
  • Developmental Neuroscience
  • Medicine(all)

Cite this

Use of laser microdissection in the investigation of facial motoneuron and neuropil molecular phenotypes after peripheral axotomy. / Mesnard, Nichole A.; Alexander, Thomas D.; Sanders, Virginia M.; Jones, Kathryn.

In: Experimental Neurology, Vol. 225, No. 1, 09.2010, p. 94-103.

Research output: Contribution to journalArticle

Mesnard, Nichole A. ; Alexander, Thomas D. ; Sanders, Virginia M. ; Jones, Kathryn. / Use of laser microdissection in the investigation of facial motoneuron and neuropil molecular phenotypes after peripheral axotomy. In: Experimental Neurology. 2010 ; Vol. 225, No. 1. pp. 94-103.
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