Probing Functional Properties of Nociceptive Axons Using a Microfluidic Culture System
Figure 4
An in vitro model of traumatic nerve injury using adult mouse DRG cultures in MFCs.
(A) Sensory neurons in MFC (left) can be axotomized in vitro using a suction pipette (middle), following which axons regenerate through the microgrooves (right). All images show staining for β3tubulin. (B-C) Axonal Nav1.8 expression is upregulated 3d after axotomy in the regenerating axons. Images show Nav1.8 staining. Right graphs show quantification of staining as fold change in Nav1.8 expression in the cell soma, microgroove-contained axons and nerve endings, before and after axotomy (*p < 0.05, Student’s t-test, n = 3). (D) Axotomized neurons are sensitized compared to control neurons, evidenced by the increased percentage of responders after axonal stimulation with capsaicin or KCl (left, *p < 0.05, **p < 0.01 vs naïve, Student’s t-test, n = 3 independent experiments). The magnitude of Ca2+ responses to axonal stimulation following axotomy was not significantly different compared to control neurons (right). Scale bars: A = 200 μm, B = 50 μm.