Review of the Thermal Gradient Ring for mice temperature-dependent behaviors
Review of the Thermal Gradient Ring for mice temperature-dependent behaviors
Understanding how organisms perceive and respond to temperature changes is fundamental to unraveling the intricacies of sensory processing and thermoregulation. In recent years, research efforts have increasingly focused on elucidating the role of Transient Receptor Potential (TRP) channels in mediating temperature-dependent behaviors in mammals, including mice. The recent study titled "Thermal Gradient Ring for analysis of temperature-dependent behaviors involving TRP channels in mice" has shed light on this complex interplay, highlighting the crucial role of the Thermal Gradient Ring (TGR) in advancing our understanding of thermosensation.
The TGR, based on the paper "Comprehensive thermal Preference Phenotyping in Mice using a Novel Automated Circular Gradient Assay”, represents a significant technological advancement in the field of preclinical research, providing researchers with a sophisticated tool to investigate temperature-dependent behaviors with unprecedented precision. This innovative apparatus consists of a circular arena with a radial temperature gradient ranging from cooler to warmer zones, allowing for precise control and manipulation of temperature conditions. Mice are placed in the ring, and their movements are tracked to analyze temperature preferences and thermal responses.
Fig. 1 - Thermal Gradient Ring system. The Thermal Gradient Ring viewed from above (left) and a schematic representation of the temperature gradient zones with cooler and warmer temperatures shown in blue and red, respectively (right). Two temperature control devices under the ring create a thermal gradient on the floor of the apparatus. There are 12 zones on one half of the ring. These zones and the gradient are duplicated on the other half.
Recently Prof. Tominaga and his team from the Division of Cell Signaling of the National Institute for Physiological Sciences (National Institutes of Natural Sciences, Okazaki, Japan) published a method paper on the results achieved and the potential for neuroscience research of the Ugo Basile Thermal Gradient Ring (TGR). The paper is open access and available at the link: https://jps.biomedcentral.com/articles/10.1186/s12576-024-00903-w
Here below we report the highlights of the above mentioned paper Thermal gradient ring for analysis of temperature‑dependent behaviors involving TRP channels in mice, by Makoto Tominaga, Tomoyo Ujisawa, Jing Lei and Makiko Kashio.
In the study, researchers utilized the TGR to explore the involvement of TRP channels in temperature-dependent behaviors in mice, being their role in these behaviors not fully understood. By employing the TGR the scientists achieved to overcome the limitations of previous methods, like the lack of temperature resolution of two-temperature choice systems or linear thermal gradient devices which do not exclude the possibility for the mouse to remain in a corner. In the TGR, the temperature resolution and range can be adjusted and the mouse can move freely in a circle. Additionally, thanks to a video-tracking system, the TGR automatically delivers results on the time spent on each of the twelve temperature zones, the preferred temperature and several other automated parameters to describe animal temperature behavior.
Fig. 2 - Analysis of crossing behaviors to warmer and cooler temperature zones. A Comparison of number of crossings from 1/24 zones (10 °C) or 12/13 zones (45 °C) in 60 min made by wild-type (WT, n = 15), TRPM8KO (n = 14) and TRPV1KO (n = 10) mice. B Comparison of percentage of mice that crossed 1/24 zones or 12/13 zones in 60 min among WT (n = 15), TRPM8KO (n = 14) and TRPV1KO (n = 10) mice. *** p < 0.001 by one-way ANOVA multiple comparison
Using genetically modified mice lacking specific TRP channel subtypes, the researchers aimed to dissect the contributions of individual channel to thermosensation. The findings revealed distinct temperature preferences and behaviors in wild-type mice, with a clear preference for specific temperature zones within the gradient. Interestingly, mice lacking certain TRP channel subtypes exhibited altered thermal responses, underscoring the importance of these channels in temperature sensing, preference, avoidance, and elucidating the nuances of temperature-dependent behaviors in addition to uncovering the intricate interplay between TRP channels and thermosensation.
The study emphasizes the importance of analyzing multiple parameters like travel distance and moving speed alongside spent time to fully understand temperature-dependent behaviors. Results revealed insights into mice's response to cold temperatures and the role of TRP channels. The design's temperature duplicates and continuous monitoring ensure accuracy and minimize hiding spots, while circadian changes in body temperature do not affect assay results. Overall, the Thermal Gradient Ring emerges as a robust tool for comprehensive analysis of temperature-dependent behaviors in mice, enabling significant advancements in TRP channel research.
Understanding temperature-dependent behaviors and the underlying molecular mechanisms, such as TRP channel function, has implications for various fields. In neuroscience, elucidating how organisms perceive and respond to temperature changes contributes to understanding sensory processing and neural circuitry. Additionally, insights gained from this study could inform research on thermal regulation, pain perception, and environmental adaptation in mammals.
Future research could focus on exploring the roles of different TRP channel subtypes in thermal sensation and behavior. Additionally, investigating the neural circuits involved in temperature processing and the integration of thermal information with other sensory modalities would further enhance our understanding of thermosensation.
Fig. 3 - TMEM79-deficient mice exhibit a strong preference for a warmer temperature compared with wild-type mice. “Spent time” by wild-type, TRPV3−/−, or TMEM79−/− mice in each temperature zone during a 1 h recording. The data were statistically analyzed with a mixed-effects ANOVA with Geisser-Greenhouse correction. All data and error bars represent the mean ± SEM. *, P < 0.05; **, P < 0.01.
In conclusion, the study "Thermal gradient ring for analysis of temperature-dependent behaviors involving TRP channels in mice" provides valuable insights into the mechanisms underlying temperature sensing and behavioral responses in mammals. By utilizing innovative experimental techniques and genetic manipulations, researchers have shed light on the role of TRP channels in mediating temperature-dependent behaviors. This research contributes to our broader understanding of sensory processing and thermoregulation, with potential implications for various fields, including neuroscience and physiology.
Learn more about Ugo Basile TGR: https://ugobasile.com/products/categories/pain-and-inflammation/thermal-gradient-ring-tgr-zimmermann-s-method
