Related Experiment Video
Updated: Jun 19, 2026
05:00
Short-Duration Hypothermia Induction in Rats using Models for Studies examining Clinical Relevance and Mechanisms
Published on: March 3, 2021
Changes in hypothalamic and body temperatures during 24 hours in rats
Mahesh Kumar Kaushik1, Hruda Nanda Mallick, Velayudhan Mohan Kumar
1Department of Physiology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110 029.
Indian Journal of Physiology and Pharmacology
|October 9, 2009
Summary
This study monitored rat body and hypothalamic temperatures over 24 hours. Hypothalamic temperature was higher at night and showed greater daily variation in these nocturnal animals.
Area of Science:
- Physiology
- Neuroscience
- Chronobiology
Background:
- Limited data exists on simultaneous body and hypothalamic temperature measurements in rats.
- Understanding thermoregulation is crucial for physiological and neurological research.
Purpose of the Study:
- To simultaneously record and compare body and hypothalamic temperatures in rats over a 24-hour period.
- To investigate the circadian variations and relationships between these two temperature measurements.
Main Methods:
- Rats were maintained at a controlled ambient temperature (26 +/- 1°C).
- Body and hypothalamic temperatures were recorded for 24 hours on three alternate days.
- Data analysis focused on diurnal changes and differences between the two temperature recordings.
Main Results:
- Hypothalamic temperature was significantly higher than body temperature during nighttime hours.
- The magnitude of circadian variation was greater for hypothalamic temperature compared to body temperature.
- Both temperatures exhibited closely associated diurnal changes despite differing levels.
Conclusions:
- This study provides novel data on the distinct patterns of body and hypothalamic temperature in rats.
- Hypothalamic thermoregulation shows a more pronounced circadian rhythm than overall body temperature.
- The findings contribute to a better understanding of thermoregulation and circadian rhythms in nocturnal mammals.
Related Concept Videos
01:07Body Temperature
Body temperature reflects the equilibrium between heat production and heat loss within the body. Most heat is generated by metabolically active tissues, particularly the liver, heart, brain, kidneys, and endocrine organs. At rest, skeletal muscles contribute 20–30% of total heat production, but during vigorous exercise, this can increase up to 30–40 times.
The average body temperature is approximately 37°C (98.6°F) and typically ranges from 36.1–37.2°C (97–99°F), remaining relatively stable...
The average body temperature is approximately 37°C (98.6°F) and typically ranges from 36.1–37.2°C (97–99°F), remaining relatively stable...
01:25Body Temperature
The body's temperature, measured in degrees, is determined by the balance between heat production and dissipation to the surrounding environment. For instance, if exercising vigorously, the body will produce more heat, causing sweat and dissipating that heat. Despite extreme environmental conditions and physical exertion, the human temperature-control system maintains a constant core body temperature (the temperature of deep tissues, which are the tissues located beneath the skin and other...
01:26Thermoregulation
The human body has a sophisticated thermoregulation system that employs negative feedback mechanisms to maintain an optimal core temperature. When the core temperature drops, peripheral and central thermoreceptors send signals to the hypothalamus, activating the heat-promoting center. This center triggers several responses aimed at increasing the core temperature. First, vasoconstriction reduces the flow of warm blood from internal organs to the skin so that the heat is not lost from the skin,...
01:28Factors Affecting Body Temperature
As a nurse, it is vital to understand the factors affecting body temperature to monitor variations and effectively evaluate deviations from regular.
Factors may include:
Factors may include:
01:19Homeostatic Imbalances in Body Temperature
Hyperthermia occurs when the body's temperature becomes unusually high, often due to heat exposure, intense physical activity, or certain illnesses. This condition can create a dangerous cycle where elevated body temperature increases the metabolic rate, generating more heat and potentially leading to organ failure and brain damage. A severe form of hyperthermia, called heat stroke, can raise body temperature to life-threatening levels. Fever, on the other hand, is a controlled form of...
01:25Increased Body Temperature
A body temperature above 38°C (100.4 °F) is known as fever or pyrexia, and a person with fever is termed 'febrile.' Typically, the hypothalamus, a part of the brain that acts as the body's thermostat, regulates body temperature through a thermoregulatory setpoint. It receives signals from cold and warm thermal receptors throughout the body and adjusts the body's temperature accordingly. Fever occurs when this hypothalamic setpoint is altered, usually in response to an infection or illness.