Chronic deafferentation in monkeys differentially affects nociceptive and nonnociceptive pathways distinguished by specific calcium-binding proteins and down-regulates γ-aminobutyric acid type A receptors at thalamic levels

Academic Article

Abstract

  • Chronic deafferentation of skin and peripheral tissues is associated with plasticity of representational maps in cerebral cortex and with perturbations of sensory experience that include severe 'central' pain. This study shows that in normal monkeys the nonnociceptive, lemniscal component of the somatosensory pathways at spinal, brainstem, and thalamic levels is distinguished by cells and fibers immunoreactive for the calcium-binding protein parvalbumin, whereas cells of the nociceptive component at these levels are distinguished by immunoreactivity for 28-kDa calbindin. Long-term dorsal rhizotomies in monkeys lead to transneuronal degeneration of parvalbumin cells at brainstem and thalamic sites accompanied in the thalamus by a down-regulation of γ-aminobutyric acid type A receptors and an apparent increase of activity of calbindin cells preferentially innervated by central pain pathways. Release from inhibition and imbalance in patterns of somatosensory inputs from thalamus to cerebral cortex may constitute subcortical mechanisms for inducing changes in representational maps and perturbations of sensory perception, including central pain.
  • Authors

    Digital Object Identifier (doi)

    Author List

  • Rausell E; Cusick CG; Taub E; Jones EG
  • Start Page

  • 2571
  • End Page

  • 2575
  • Volume

  • 89
  • Issue

  • 7