Pain and Touch: Roles for C-Tactile Afferents in Pain Inhibition and Tactile Allodynia

  • Jaquette Liljencrantz
  • Mark Pitcher
  • M. Catherine Bushnell
  • Håkan OlaussonEmail author


In humans there is a positive correlation between the pleasantness perception of soft skin stroking and the firing rate of unmyelinated C-low-threshold mechanoreceptive afferents (often abbreviated C-LTMR in animals and C-tactile and CT afferents in humans). CT-targeted touch reduces heat pain in humans suggesting that activation of the CT system modulates pain perception. This finding is supported by animal work which has shown that C-LTMRs inhibit nociceptive signaling at the spinal cord level, release a protein (TAFA4) with analgesic effects, and have positively reinforcing and anxiolytic behavioral effects. However, under pathophysiological conditions, research in mice and humans instead suggests a role for CLTMRs and CTs in tactile allodynia. There is a divergence in results with some studies pointing to CLTMRs/CTs driving tactile allodynia, whereas others suggest a modulatory role.


C-tactile C-low threshold mechanoreceptor Affective touch Pain Allodynia VGLUT3 TAFA4 


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Copyright information

© Springer Science+Business Media New York 2016

Authors and Affiliations

  • Jaquette Liljencrantz
    • 1
  • Mark Pitcher
    • 1
  • M. Catherine Bushnell
    • 2
  • Håkan Olausson
    • 3
    • 4
    Email author
  1. 1.Anaesthesiology and Intensive CareSahlgrenska University HospitalGöteborgSweden
  2. 2.National Center for Complementary and Integrative HealthNational Institutes of HealthBethesdaUSA
  3. 3.Center for Social and Affective NeuroscienceLinköping UniversityLinköpingSweden
  4. 4.Institute of Neuroscience and PhysiologyThe Sahlgrenska Academy, University of GothenburgGothenburgSweden

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