Ipsilateral cortical fMRI responses after peripheral nerve damage in rats reflect increased interneuron activity

• DOI: 10.1073/pnas.0903153106
• Publication Date: 2009-08-05T01:44:00Z
• Authors: Galit Pelled; Debra A. Bergstrom; Patrick L. Tierney; Richard S. Conroy; Kai-Hsiang Chuang; David Yu; David A. Leopold; Judith R. Walters; Alan P. Koretsky
• Keywords: Interneuron; Forelimb

In the weeks following unilateral peripheral nerve injury, deprived primary somatosensory cortex (SI) responds to stimulation of ipsilateral intact limb as demonstrated by functional magnetic resonance imaging (fMRI) responses. The neuronal basis these responses was studied using high-resolution fMRI, in vivo electrophysiological recordings, and juxtacellular labeling rats that underwent an excision forepaw radial, median, ulnar nerves. These nerves were exposed but not severed control rats. Significant bilateral increases fMRI SI observed denervated healthy rats, concordant with local field potential (LFP) amplitude increased incidence single units responding compared contrast, SI, associated a minimal change LFP responding. Based on action duration, labeling, immunostaining results, neurons identified interneurons. results suggest reflect interneuron activity.