Picospritzer 3 injector

On surgery day, rats (290–340 g) were anesthetized by isoflurane inhalation (1%–3%) or IP injection of ketamine (88 mg/kg; Ketalar, Cantonal Pharmacy Zurich) and xylazine (5 mg/kg; Rompun 2%, Cantonal Pharmacy Zurich), and NG were exposed. A glass capillary (50 μm tip) was used to administer 1.5 μL viral solution into each NG with a Picospritzer III injector (Parker Hannifin) as previously described (Krieger et al., 2016 (link)). Injections were performed bilaterally into NG.

Mice received a subcutaneous injection of carprofen (5 mg/kg; Henry Schein) and underwent anesthesia (isoflurane,1.5–2.5%). Next, mice were placed on a heating pad on supine position and a 2 cm midline incision was made in the skin on the ventral aspect of the neck. The skin, salivary glands and underlying muscles were retracted, and the vagus nerve was blunt dissected from the carotid artery using fine-tip forceps. The NG was located by tracing the vagus nerve toward the base of the skull, and then exposed by retracting surrounding muscles and blunt dissection of connective tissues. A glass micropipette filled with viral construct attached to a micromanipulator was used to position and puncture the NG. A total of 0.5 μl was injected unilaterally into the NG using a Picospritzer III injector (Parker Hannifin, Pine Brook, NJ). Incision was closed and post-op analgesic was administered at 24 hours. Mice were given at least 2 weeks for recovery and viral expression prior to experimentation.