A low-cost telemetry system suitable for measuring mouse biopotentials

The ability to generate specific genetic mutations in mice is a powerful tool to study normal and pathophysiological function. In order to determine the effects of a mutation, measurement of physiological variables, such as biopotentials, is often necessary. However, such measurements can be particularly challenging to obtain from an awake, unrestrained mouse. The goal of this study was to design and implement a telemetry system suitable for recording biopotentials from a mouse. A battery-powered system was fabricated from commercially available electronic components mounted on a small circuit board. The frequency response of the system was measured over a range of frequencies and found suitable for recording biopotentials in mice and larger animals. We affixed the circuit board externally to a mouse and connected surface electrodes to measure electrocardiograms (ECG). The size and weight of the board did not disturb normal behavior over 30-60 min. Recorded ECGs had easily identifiable components relevant to physiological parameters and had a similar frequency spectrum compared to recordings obtained from a commercially available measurement system. In conclusion, the telemetry system was low-cost due to the availability of the components, straightforward to implement, and provided biopotential recordings suitable for measuring physiological parameters in an awake mouse.