Nagahama Institute Researchers Identify Specific Amino Acid Sequence Regulating Cold Sensitivity in Cold-Preferring Salamanders

Researchers identify a specific 8-amino acid sequence in salamanders that diminishes cold sensitivity, explaining how they adapt to cooler environments.

By: AXL Media

Published: Mar 25, 2026, 5:19 AM EDT

Source: Information for this report was sourced from Wiley

The Biological Basis of Thermal Navigation

The ability of animals to navigate their environments depends heavily on specialized protein channels located within sensory neurons. These channels act as biological thermometers, opening at specific temperature ranges to trigger the neural signals that allow an animal to move toward optimal climates. New research conducted at the Nagahama Institute of Bio-Science and Technology in Japan has focused on the TRPM8 channel, which is primarily responsible for sensing cold. By comparing different amphibian species, scientists have uncovered how evolutionary pressures have modified these proteins at the molecular level to suit the specific thermal preferences of varied habitats.

Comparative Sensitivity Between Frogs and Salamanders

The study’s most striking finding is the marked difference in cold sensitivity between frogs, which generally thrive in warmer climates, and salamanders, which prefer cooler environments. While the TRPM8 channel in frogs reacts sharply to decreasing temperatures, the version found in several salamander species exhibits a significantly diminished response. This reduced sensitivity is not a defect, but rather a specialized adaptation. By having a "muted" reaction to the cold, these salamanders can remain functional and comfortable in environments that would trigger a distress response or avoidant behavior in other amphibians.

Pinpointing the Molecular Trigger

To understand the cause of this diminished sensitivity, the investigators performed a detailed analysis of the TRPM8 protein structure. They successfully isolated a specific cluster of eight amino acids located at the N-terminus of the protein in cold-preferring salamanders. The team discovered that this precise sequence is what determines the low temperature sensitivity of the entire channel. This finding provides the first evidence of amino acid-level changes responsible for the thermal sensing characteristics of tailed amphibians, marking a significant milestone in molecular biology and evolutionary studies.