Effects of GABAA receptor inhibition on response properties of barrel cortical neurons in C-Fiber-depleted rats

Rasoul Farazifard, Roozbeh Kiani, Hossein Esteky

Research output: Contribution to journalArticle

Abstract

C-fiber depletion results in expansion of low threshold somatosensory mechanoreceptive fields. In this study, we investigated the role of intact C-fibers in GABAA-mediated inhibition in barrel cortical neurons. We used electronically controlled mechanical stimulation of whiskers to quantitatively examine the responses of barrel cells to whisker displacements. After systemic injection of picrotoxin neuronal responses were recorded at 5 min intervals for 20 min and then at 10 min intervals for 100 min. Picrotoxin injection caused a 3-fold increase in response magnitude of adjacent whisker stimulation and 1.4-fold increase in response magnitude of principal whisker stimulation with a maximum enhancement 50 min after the injection. There was no significant change in spontaneous activity following picrotoxin injection. The response enhancement and receptive field expansion observed in normal rats were completely absent in the C-fiber-depleted rats. These results suggest that the GABAA-mediated inhibition that modulates the receptive field functional organization of the barrel cortex depends on intact C-fibers.

Original languageEnglish (US)
Pages (from-to)27-32
Number of pages6
JournalBrain Research
Volume1050
Issue number1-2
DOIs
StatePublished - Jul 19 2005

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Keywords

  • Barrel cortex
  • C-fibers
  • Capsaicin
  • GABA

ASJC Scopus subject areas

  • Neuroscience(all)
  • Molecular Biology
  • Clinical Neurology
  • Developmental Biology

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