1300a 3 in 1 whole animal system

Open‐field activity test, grip strength, and assessment of in vivo muscle force were performed at the Toronto Centre for Phenogenomics. For the open‐field test, mice were placed in the frontal center of a transparent Plexiglas open field (41.25 cm × 41.25 cm × 31.25 cm) illuminated by 200 lx. A trained operator, unaware of the nature of the projects and treatments, performed the experiments. The VersaMax Animal Activity Monitoring System recorded vertical activities and total distance traveled for 20 min per animal.
Forelimb Grip Strength was measured with the grip strength test apparatus (BIO‐GS3, Bioseb). The mice were lowered over the grid keeping the torso horizontal and allowing the forepaws to attach to the grid. Then, the mice were gently pulled back by their tails and maximal grip strength was recorded. The data are shown as the average of 3 pulls, corrected to body weight.
An in vivo muscle‐contraction test was performed using 1300A: 3‐in‐1 Whole Animal System and analyzed using dynamic muscle control/analysis (DMC/DMA) high‐throughput software suite (Aurora Scientific). The mice were anesthetized by an intraperitoneal injection of a ketamine/xylazine cocktail at 100 mg/kg and 10 mg/kg of body weight, respectively. Percutaneous electrodes were placed in the tibialis anterior, and specific tetanic force at 175 Hz was recorded and corrected according to body weight.

The maximal isometric torque of the ankle gastrocnemius muscle (GA) was measured in control and ischemic limbs using the 1300A 3-in-1 Whole Animal System (Aurora Scientific, Aurora, ON, Canada) as previously described [44 (link)]. Animals were kept under anesthesia (3% isoflurane via a nose cone) throughout the measurement process. The foot was immobilized with adhesive tape to a footplate of a torque cell. Resting tension and muscle length were continually adjusted for each muscle to obtain the optimal twitch contraction force. A subcutaneous electrode was used to stimulate the ankle dorsiflexors via the fibular nerve. Proper electrode position was determined by a series of isometric twitches. After a 5-min equilibration period, isometric tension was evaluated with stimulations of 150 Hz for 300 ms. Data were analyzed to determine muscle torque using the Dynamic Muscle Analysis software (ASI 611A v.5.321; Aurora Scientific).

The 1300 A 3-in-1 whole animal system (Aurora Scientific) was used for in vivo muscle force analysis. Mice were first anesthetized and kept warm by heat lamp. The maximum twitch and tetanic force were evaluated according to manufacturer’s instruction. Five repetitive tests were performed for each limb and DMA software (Aurora scientific) was used for results analysis.

In vivo TA muscle force analysis was performed with 1300 A 3-in-1 whole animal system (Aurora Scientific) as previously described^{60 (link)–62 (link)}. Mice were anesthetized by 3-bromo-2-fluoro-phenyl methanol (31.2 g/kg body weight) injection and kept warm by heat lamp. The hind limb was shaved and immobilized by fixing the leg in a frame without disturbing the blood flow. Tie around the patella ligament of the distal TA muscle using a bread silk suture. Make an incision to expose the sciatic nerve and tie another knot around the proximal end of the sciatic nerve. Attach the distal TA tendon suture loop to the lever arm hook of the instrument and measure the contractile force. During the process, TA muscle was constantly superfused with pre-warmed 37 °C Ringer’s buffer (118 mM NaCl, 4.75 mM KCl, 1.18 mM KH₂PO₄, 1.18 mM MgSO₄, 2.5 mM CaCl₂, 25 mM NaHCO₃, and 11 mM glucose). The results were analyzed by DMA software (Aurora scientific). For each treatment, five independent experiments were performed. The identity of each mouse was blinded to the personal who operated the measurement.