How many heartbeats per minute does a mouse have? - briefly
A typical laboratory mouse exhibits a resting heart rate of roughly 500–600 beats per minute. During stress or vigorous activity, the rate can exceed 700 beats per minute.
How many heartbeats per minute does a mouse have? - in detail
Mice exhibit exceptionally rapid cardiac cycles compared with larger mammals. Resting heart rates typically range from 300 to 800 beats per minute, with most laboratory strains averaging approximately 600 bpm under calm conditions.
Key determinants of the observed frequency include:
- Species and genetic background: Certain wild‑type species such as Mus musculus domesticus display rates near the lower end of the range, whereas engineered strains may reach higher values.
- Age: Neonatal pups can exceed 1 000 bpm, while adult individuals settle around 500–700 bpm.
- Ambient temperature: Cooler environments depress the rhythm; a rise of 5 °C can increase the rate by 10–15 %.
- Physiological state: Physical exertion, stress, or anesthetic agents produce transient elevations or depressions.
Measurement techniques commonly employed are:
- Electrocardiography (ECG) with surface electrodes, providing precise beat‑to‑beat intervals.
- Photoplethysmography using infrared sensors, suitable for high‑throughput screening.
- Implantable telemetry devices, allowing continuous monitoring in freely moving subjects.
Comparative data illustrate the scaling relationship between body mass (M) and heart rate (HR), approximated by the allometric equation HR ≈ 70 · M^‑0.25. For a mouse weighing 25 g, the equation predicts roughly 600 bpm, aligning with empirical observations.
Physiological implications of such high rates include elevated metabolic demand, rapid oxygen delivery, and brief cardiac cycle phases. Consequently, experimental designs involving murine models must account for these parameters when interpreting cardiovascular outcomes.