The modular treadmill is comprised of two lanes that can be used singly or as one “master” lane that is paired to a “slave” lane. The exercise belts are individually enclosed in a chamber. The chambers have a "Metabolic Option" that can be connected to the Oxymax calorimetry system to provide measurements of VO2, VCO2, RER, and energy expenditure. The treadmill chambers provide each mouse with 1.75" (4.4 cm) of headroom and are 2" (5 cm) wide. The length of the running surface is 12" (25.4 cm), and the volume of the enclosure is approximately 2 liters. The incline of each treadmill lane is manually adjustable in 5° increments from -10° to +25°. Treadmill speed is adjustable over the range of 2 to 50 meters per minute with a resolution of 0.1 meters per minute.
The individual chambers are equipped with an electrical stimulus grid to encourage running. A scrambled electrical stimulus is presented as a series of 200 millisecond pulses with an adjustable pulse repetition rate of one to four per second. The intensity is also adjustable from 0.35mA to 3.4mA. LED lamps indicate stimulus grid excitation and switches are provided to engage or terminate stimulus in each lane.