Surgical Implantation of Temperature Telemetric Monitoring System in Mouse Model: A Surgical Procedure to Implant Temperature Telemetric Device to Measure Mouse Core Body Temperature

All procedures involving animal models have been reviewed by the local institutional animal care committee and the JoVE veterinary review board

1. Surgical Implantation of the Telemetric Temperature Monitoring System

1. Upon arrival from the vendor, allow the animals to rest in the vivarium for at least 1 week prior to surgery to minimize the stress of transportation.
2. Group house the mice (maximum of 5 per cage under local IACUC guidelines) until the day of surgery for temperature telemetric device implantation. House them in standard 7.25" (W) x 11.75" (L) x 5" (H) cages containing corncob bedding. Maintain the light cycle on a 12 x 12 light cycle (on: 7 AM; off: 7 PM). Maintain the housing temperature at 20–22 °C and relative humidity (RH) at 30%–60%. Provide the standard chow diet and water ad libitum until the EHS protocol.
   NOTE: The rationale for individual housing is to avoid frequent fighting injury in male C57bl/6J mice and to provide ample opportunity for spontaneous wheel running for each mouse.
3. For placement of the telemetry devices, anesthetize the mouse with isoflurane (4%, 0.4–0.6 L/min of O2 flow) in an induction chamber. Then, place the mouse under continuous anesthesia via a nose cone (1.5%, 0.6 L/min).
4. Use eye lube, such as a vet ointment, to protect the animal's eyes from damage or injury during surgery.
5. To prepare the surgical site, shave the lower abdomen with small animal hair clippers or use a commercially available hair remover. Administer the first dose of subcutaneous buprenorphine (0.1 mg/kg) during this time.
6. Scrub the area with three washes of povidone-iodine (or similar germicidal scrub) followed by 70% isopropyl alcohol rinse (or sterile saline depending on local veterinary requirements). Then, transfer the mouse to the surgical area.
7. Use an adhesive drape to isolate the surgical site on the mouse. Using sterile instruments and aseptic technique, make a ~1 cm incision on the midline along the linea alba, about 0.5 cm from the costal margin. Then, separate the skin from the muscle layer and make a slightly smaller incision on the linea alba, careful not to damage the bowels or internal organs.
8. Once the muscle layer is open, place the sterile telemeter (miniature reusable battery-free radiotelemetry device; 16.5 x 6.5 mm) into the intraperitoneal cavity in front of the caudal arteries and veins and dorsal to the digestive organs to allow it to float freely.
   NOTE: All telemeters are cleaned with soap and water, thoroughly rinsed and gas sterilized with ethylene oxide between usages. If gas sterilization is not available, immersion in sterilization solutions (following manufacturer’s recommendation for dilution and immersion time) is accepted to disinfect and sterilize the telemeters.
9. Close the abdominal opening with a sterile 5-0 absorbable suture and close the skin using a simple interrupted stitch with 5-0 proline suture.
   NOTE: Allowing the telemeter to float in the abdominal compartment without tying it to the abdominal wall (a method recommended by the manufacturer) has been demonstrated to be successful and preferred by the authors to eliminate excess tension in the abdominal wall during healing. Further, this has no impact on the receiver's ability to obtain the signal from the emitter.
10. Place the mouse in its clean cage with a portable heating pad under the cage. Monitor the mouse every 15 min during the first hour of recovery from anesthesia, and then return to the animal housing facility.