Type III Nrg1, TRPV1 and Pain Sensation CAGCCACAAACA; TMc 39: TAGGCCACCACACACATGAT, b3 39: ACAAGAAAGCAGCACCGACT. Statistical Significance Normally distributed data was evaluated using a Student’s t-test or an ANOVA with a Holm-Sidak or Fischer’s PLSD post-hoc test for multiple comparisons. Non-normally distributed data was compared using a Mann-Whitney Rank Sum test or an ANOVA on Ranks with a Dunn’s post-hoc test for multiple comparisons. Statistical significance was set at p,0.05. Results Type III Nrg1 is found in adult nociceptive sensory neuron soma and peripheral nerve terminals In order to determine the pattern of Type III Nrg1 expression in nociceptive peripheral sensory neurons of the adult mouse, we used double immunofluorescent labeling of transverse sections through mouse lumbar DRG (Figure 1A) and plantar hindpaw skin (Figure 1B). In L4/L5 DRG Type III Nrg1 protein is expressed in both major classes of nociceptive sensory neurons, the Figure 1. Type III Nrg1 expression in adult nociceptive sensory neuron soma and peripheral nerve terminals in vivo. (A) Type III Nrg1 (b,e,h) is found in nociceptive TrkA+ (a–c) and IB4+ (d–f), as well as TRPV1+ (g–i) sensory neuron soma in lumbar dorsal root ganglia. (B) Type III Nrg1 (b9,e9) is found in nociceptive peripheral nerve terminals innervating the plantar hindpaw skin as marked with an antibody against CGRP (a9) as well as TRPV1 (d9). White arrows indicate examples of soma or nerve terminals that are expressing both Type III Nrg1 and the particular sensory marker. All scale bars equal 10 mm. doi:10.1371/journal.pone.0025108.g001 PLoS ONE | www.plosone.org 5 September 2011 | Volume 6 | Issue 9 | e25108