A threshold problem! Most DRG Sensory Neurons Are Modality-Specific, Not Polymodal



Have you seen the ongoing discussion?

As a disclaimer, I consider myself part of the church of the polymodal afferent, thus I found the results difficult to digest.

What has come to my attention is that on the Emery paper they used a 2g VFH to mechanically stimulate the receptive field and evaluate polymodality. What is your experience in naive-skin electrophysiology? Do all your mechanically sensitive neurons have thresholds below 2g? Mine sure don’t. In fact I tend to find a large population of C fibers that have thresholds even above 4 grams. Did they just miss a huge part of the polymodal population because they did not use a stronger von Frey? Would that explain their discrepancy with the Woodbury paper where they used ascending forces up to 500mN (~50g)?

What do you guys think? Tag your electrophysiologist, I look forward to hearing your opinions.

@fmoehring @achamess