Reactive astrocytic responses to denervation in the motor cortex of adult rats are sensitive to manipulations of behavioral experience

Neuropharmacology. 2000 Mar 3;39(5):743-55. doi: 10.1016/s0028-3908(99)00272-5.


Recent research has suggested that mild denervation of the neocortex of adult rats may facilitate neuronal growth in response to behavioral changes. Astrocytes react to denervation, produce growth-promoting factors and are a potential mediator of this denervation-facilitated growth. The present study assessed whether astrocytic reactions to denervation vary dependent upon post-injury behavioral experience. Denervation of the transcallosal afferents to the motor cortex was induced via partial transections of the corpus callosum. Transected- or sham-operated rats were then either forced to use the opposite forelimb (via limb-restricting vests) or permitted to use both forelimbs normally for 8 days. In the motor cortex, the surface density of glial fibrillary acidic protein (GFAP)-immunoreactive (IR) astrocytic processes and the density of basic fibroblast growth factor (FGF-2)-IR glial cells was significantly increased as a result of transections alone and as a result of forced forelimb-use alone in comparison to controls. The combination of transections and forced-use significantly enhanced GFAP-IR in comparison to all other groups, but did not further enhance FGF-2-IR. These findings are consistent with behavior and denervation having interactive influences on astrocytic reactivity in the motor cortex. These results also raise the possibility that astrocyte-mediated support of neural restructuring after brain injury might be enhanced with appropriate post-injury behavioral manipulations.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Astrocytes / cytology
  • Astrocytes / metabolism
  • Astrocytes / physiology*
  • Behavior, Animal / physiology*
  • Cell Count
  • Corpus Callosum / pathology
  • Corpus Callosum / physiology
  • Corpus Callosum / surgery
  • Denervation
  • Fibroblast Growth Factor 2 / metabolism
  • Forelimb / physiology
  • Glial Fibrillary Acidic Protein / metabolism
  • Gliosis / pathology
  • Immobilization / physiology
  • Immunohistochemistry
  • Male
  • Motor Cortex / cytology
  • Motor Cortex / pathology
  • Motor Cortex / physiology*
  • Posture / physiology
  • Rats
  • Rats, Long-Evans
  • Restraint, Physical / instrumentation
  • Somatosensory Cortex / pathology
  • Somatosensory Cortex / physiology


  • Glial Fibrillary Acidic Protein
  • Fibroblast Growth Factor 2