4 0 sterile silk suture

Following baseline (BL) behavioral assessment, the surgical procedure for chronic constriction of the sciatic nerve was performed as previously described (Bennett and Xie, 1988), but modified for the mouse (Ignatowska-Jankowska et al., 2015 (link)). In brief, the mice were anesthetized with isoflurane (induction 5% vol. followed by 2.0% in oxygen), and the mid to lower back and the dorsal left thigh were shaved and cleaned with 75% ethanol. Using aseptic procedures, the sciatic nerve was carefully isolated, and loosely ligated with three segments of 4-0 silk suture (Ethicon, Somerville, NJ). The overlying muscle was closed with (1) 4-0 sterile silk suture (Ethicon, Somerville, NJ), and animals recovered from anesthesia within approximately 5 min. In these studies the contralateral paw was used as a within subject non-allodynic control paw, as this procedure produces ipsilateral allodynia, only (Kinsey et al., 2010 (link); Ignatowska-Jankowska et al., 2015 (link)). Subjects were tested with drug or vehicle between 5 and 18 days after surgery.

Following BL behavioral assessment, the surgical procedure for chronic constriction injury (CCI) of the sciatic nerve was completed as previously described (Wilkerson et al., 2016 (link); Wilkerson et al., 2020 (link)). Briefly, in isoflurane-(induction 5% vol. followed by 2.0% in oxygen) anesthetized mice, the mid- to lower back and the dorsal left thigh shaved and cleaned with 75% ethanol. Using aseptic procedures, the sciatic nerve was carefully isolated, and loosely ligated with 3 segments of 5–0 chromic gut sutures (Ethicon, Somerville, NJ). Sham surgery was identical to CCI surgery but without the loose nerve ligation. The overlying muscle was sutured closed with (1) 4–0 sterile silk suture (Ethicon, Somerville, NJ), and animals recovered from anesthesia within approximately 5 min. Animal placement into either CCI or sham surgical groups was randomly assigned. As previously described, use of chromic gut suture in the CCI model leads to bilateral mechanical allodynia, with similar response thresholds observed between the ipsilateral and contralateral paws (Wilkerson et al., 2012; 2016 (link); 2020 (link)).