Chronic Sensory Loss Model: Median and Ulnar Nerve Transection

All animals underwent transection and repair of the median and ulnar nerves to generate chronic sensory loss, as described in previous studies [17 (link), 29 , 30 (link)]. Animals were deeply anesthetized with ketamine hydrochloride (50 mg/kg, IP), xylazine (20 mg/kg, IP), and acepromazine (5 mg/kg) and supplemented as necessary to maintain areflexia. The animal was placed in a supine position, and a sagittal incision was made 1cm proximal to the elbow of the right forelimb. The surrounding tissue was blunt dissected to expose, separate, and transect the median and ulnar nerves. The proximal and distal nerve stumps were sutured 1 mm from the ends of an 8 mm saline-filled polyurethane tube (Micro-Renathane 0.095” I.D 0.066” O.D., Braintree Scientific, Inc., Braintree, MA), resulting in a 6 mm gap between nerve stumps. The skin incision was sutured and covered in a triple antibiotic ointment. After surgery, animals were given subcutaneous injections of sustained release buprenorphine (10 mg/kg) and 10 ml of a solution of lactated ringers with 5% dextrose. Animals were outfitted with an Elizabethan collar for 4 days to prevent autophagia. Animals were allowed to recover for 8 weeks prior to the resumption of behavioral testing.