Simultaneous Assessment of Circadian Rhythms and Sleep in Mice Using Passive Infrared Sensors: A User's Guide

Area of Science:

• Chronobiology
• Neuroscience
• Animal Behavior

Background:

• Circadian rhythms, governed by the suprachiasmatic nuclei (SCN), regulate daily activity and sleep cycles in mammals.
• Sleep is influenced by both circadian processes and a homeostatic drive that increases sleep need with prolonged wakefulness.
• Disruptions in circadian rhythms and sleep are linked to various health issues, including cognitive deficits and metabolic dysfunction.

Purpose of the Study:

• To introduce a low-cost, non-invasive, and open-source method for simultaneously assessing circadian activity and sleep in mice.
• To provide a protocol for hardware assembly, data capture, and analysis that does not require specialized electronics or data processing knowledge.

Main Methods:

• Development and assembly of a Passive Infrared (PIR) sensor system for activity and sleep recording.
• Utilizing Raspberry Pi for data collection.
• Implementing a support protocol for circadian data analysis using PIR sensor data.

Main Results:

• The described protocol enables the simultaneous assessment of circadian activity and sleep patterns in mice.
• The method is designed to be accessible to researchers without extensive expertise in electronics or data analysis.
• The system offers a cost-effective and non-invasive alternative to traditional monitoring techniques.

Conclusions:

• This open-source PIR system provides a practical and affordable solution for studying circadian rhythms and sleep in mice.
• The protocol facilitates wider research into the impact of circadian and homeostatic processes on health and disease.
• The method can serve as a valuable tool for monitoring animal welfare and physiological states.