New research results highlight the different perception of cold throughout the entire body tissue

New research results highlight the different perception of cold throughout the entire body tissue

Universidad Miguel Hernández de Elche A research team led by Félix Viana, co-director of the Laboratory of Sensory Transduction and Nociception at the Institute of Neurosciences (IN), a joint research center of the Spanish National Research Council (CSIC) and the University of Miguel Hernández Elche (UMH), has shown that the body uses different molecular mechanisms to detect cold in the skin and internal organs. These findings represent a significant advance in understanding thermal homeostasis and certain pathologies associated with cold sensitivity.

The study was recently published in the journalActa Physiologicashows that cold perception is not a homogeneous process throughout the organism. In the skin, cold is mainly detected via the ion channel TRPM8, which is specialized in sensing low temperatures and cooling sensations from the environment. In contrast, internal organs such as the lungs or stomach rely primarily on another sensor, called TRPA1, to sense drops in temperature.

This difference in molecular mechanisms explains why the sensation of cold on the surface of the body can be very different from that experienced when inhaling cold air or consuming very cold food or drinks, because each tissue type activates and uses different pathways to detect thermal changes. “The skin is equipped with specific sensors that allow us to detect ambient cold and adapt defensive behavior,” explains Félix Viana, principal investigator of the study. He adds: "In contrast, cold detection in the body appears to depend on different sensory circuits and molecular receptors, reflecting its deeper physiological role in internal regulation and response to environmental stimuli."

The study was carried out on animal models, which allowed direct analysis of the activity of sensory neurons involved in cold detection. Specifically, the team compared neurons of the trigeminal nerve, which transmits information from the skin and surface of the head, with neurons of the vagus nerve, the main sensory pathway that connects the brain to internal organs such as the lungs and digestive tract.

To study how these neurons respond to temperature changes, researchers used calcium imaging techniques and electrophysiological recordings, which allowed real-time monitoring of neuronal activation. These approaches were combined with the use of specific pharmacological agents that can block specific molecular sensors to identify which ion channels are involved in cold sensing in each neuron type.

Additionally, the team used genetically modified mice lacking the TRPM8 or TRPA1 sensors, along with gene expression analysis, to confirm the distinct roles of these channels in cold perception. This multidisciplinary approach showed that cold sensing is precisely tailored to the physiological functions of each tissue and that internal organs use molecular mechanisms that are different from those of the skin.

Our results reveal a more complex and nuanced view of how sensory systems in different tissues encode thermal information. This opens up new opportunities to study how these signals are integrated and how they may change in pathological conditions, such as certain neuropathies in which cold sensitivity is impaired.”

Katharina Gers-Barlag, Universidad Miguel Hernández de Elche

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