What is the heart rate of a mouse in beats per minute? - briefly
A typical laboratory mouse beats between 300 and 800 times per minute, with most strains averaging about 500–600 BPM.
What is the heart rate of a mouse in beats per minute? - in detail
The resting cardiac frequency of a laboratory mouse typically falls between 300 and 700 beats per minute (bpm). This interval reflects species‑specific metabolic demands and differs markedly from larger mammals.
Key determinants of the measured rate include:
- Strain: Inbred lines such as C57BL/6 display averages near 500 bpm, whereas outbred stocks may reach 600–650 bpm.
- Age: Neonatal mice exhibit rates above 800 bpm; adult values decline to the 300–500 bpm range; senescent individuals may fall below 300 bpm.
- Sex: Male mice often record slightly lower frequencies than females, though the difference rarely exceeds 10 %.
- Ambient temperature: Housing at thermoneutral conditions (≈30 °C) reduces heart rate by 10–20 % compared with standard room temperature (≈22 °C).
- Stress and handling: Acute stressors elevate cardiac output, producing transient spikes up to 900 bpm.
Measurement techniques:
- Electrocardiography (ECG): Surface or implanted electrodes provide high‑resolution traces; calibration against known standards assures accuracy within ±5 bpm.
- Telemetry: Miniaturized transmitters enable continuous monitoring in freely moving animals, capturing circadian variations.
- Photoplethysmography: Non‑invasive optical sensors detect pulse waveforms; suitable for short‑term assessments but limited by motion artifacts.
Typical experimental protocol:
- Acclimate the animal to the recording environment for at least 10 minutes.
- Maintain ambient temperature at thermoneutral levels to minimize thermal stress.
- Use anesthetic agents sparingly; agents such as isoflurane depress cardiac activity by 15–30 %.
- Record for a minimum of 5 minutes to obtain a stable average; discard outliers caused by movement.
Reference values derived from peer‑reviewed studies:
- Adult male C57BL/6: 480 ± 30 bpm.
- Adult female BALB/c: 540 ± 35 bpm.
- Aged (≥18 months) mixed strain: 280 ± 25 bpm.
Understanding these parameters facilitates accurate interpretation of cardiovascular phenotypes in genetic or pharmacological investigations.