How long do mice sleep? - briefly
Laboratory mice typically sleep 12–15 hours per day, distributed in several short bouts. Their sleep includes both REM and non‑REM phases, comparable to other mammalian species.
How long do mice sleep? - in detail
Mice typically rest for 12–14 hours within each 24‑hour cycle. Their sleep is polyphasic, consisting of multiple short bouts that average 2–5 minutes in duration. Across a full day, a laboratory mouse may experience 8–12 separate episodes, alternating between rapid eye movement (REM) and non‑REM stages. REM periods represent roughly 10–15 percent of total sleep time, while the remainder is spent in slow‑wave sleep.
Sleep patterns differ between strains and environments. Inbred laboratory strains, such as C57BL/6, often display slightly longer total sleep than wild‑derived mice, which may sleep 10–12 hours due to increased foraging activity. Age influences duration: juvenile mice sleep up to 15 hours, whereas older adults may reduce to around 10 hours. Light conditions also modulate rest; mice are nocturnal, showing peak sleep during the light phase and heightened activity during darkness.
Measurement techniques include electroencephalography (EEG) combined with electromyography (EMG) to distinguish REM from non‑REM, and infrared motion sensors that record bout frequency. Home‑cage monitoring systems provide continuous data without handling stress, improving accuracy of total sleep estimates.
Factors that alter sleep length encompass:
- Genetic modifications: knockout of circadian genes (e.g., Clock, Bmal1) can shorten or fragment sleep.
- Pharmacological agents: stimulants such as caffeine reduce total sleep by 20–30 percent; sedatives increase it proportionally.
- Environmental stressors: noise, temperature shifts, and predator cues elevate wakefulness and fragment bouts.
- Metabolic state: fasting decreases total sleep, while high‑fat diets extend non‑REM periods.
Understanding mouse sleep duration is essential for interpreting behavioral experiments, as variations in rest can affect cognition, pain perception, and metabolic outcomes. Accurate reporting of total sleep time, bout architecture, and influencing variables ensures reproducibility across studies.