Temperature-dependent differences in mouse gut motility are mediated by stress

Area of Science:

• Physiology
• Animal Models
• Gastroenterology

Background:

• Elevating mouse housing temperatures to 30°C is proposed to improve translational research.
• The impact of environmental temperature on mouse gastrointestinal physiology is not well understood.

Purpose of the Study:

• To investigate the effect of environmental temperature on mouse gastrointestinal physiology and motility.
• To explore the role of stress pathways in temperature-dependent gut motility.

Main Methods:

• Comparison of whole gut and colon transit speeds in mice housed at 22°C versus 30°C.
• Analysis of gut microbiota composition.
• Assessment of hypothalamic-pituitary-adrenal axis activity and corticotropin-releasing hormone (CRH) levels.
• Pharmacological and genetic manipulation of CRH.

Main Results:

• Mice at 22°C exhibited nearly double the whole gut transit speed compared to mice at 30°C, driven by a threefold increase in colon transit speed.
• Gut microbiota differed between temperatures but did not explain motility variations.
• Increased stress signals from the hypothalamic-pituitary-adrenal axis at 22°C were pivotal in mediating temperature-dependent gut motility.
• Depletion of CRH slowed gut motility in 22°C mice but not in 30°C mice.

Conclusions:

• Colder mouse facility temperatures (22°C) significantly increase gut motility.
• Hormonal stress pathways, particularly involving CRH, are key mediators of temperature-dependent gut motility in mice.
• Environmental temperature is a critical factor influencing gastrointestinal physiology in mouse models.