What is Menthol?

 

 

Menthol is an organic compound naturally occurring in mint plants. It is also synthetically manufactured. Menthol is widely used in a number of products and features certain therapeutic qualities. It was first isolated from peppermint oil in 1771 in the West, but it may have been in use in Japan for much longer.

 

Most of menthol's uses are related to its stimulation of the skin's cold receptors. This property makes menthol produce a cooling effect when inhaled or applied to the skin. Similarly to the capsaicin chemical found in hot peppers, which stimulates heat receptors, menthol does not actually change the skin's temperature, but merely produces the sensation of temperature change.

 

Because of its cooling effect, menthol is used in products meant to relieve skin irritation, sore throat, or nasal congestion. It may be used to treat sunburn, fever, or muscle aches as well.In traditional Asian medicine, menthol may be prescribed for nausea, diarrhea, indigestion, headache, cold, or sore throat. When used as a supplement for health reasons, menthol is usually taken in the form of peppermint oil. Products that commonly contain menthol include toothpaste, cough drops, lip balm, mouthwash, gum, and cigarettes.  

      

 

Relation Between Menthol and the Nervous System: How Does the Nervous System in the Mouth Detect Temperature Change?

 

 

 

Neurons ( nerve cells) that are responsible for detecting and transmitting sensory nervous messages about external or internal stimuli are called SENSORY NEURON. Every sensory neuron has two ends. One end is connected to a tissue in the body (a piece of skin, muscle, bone, etc.), and the other end is connected to the spinal cord.

 

These neurons are responsible for transmitting information about the body to the central nervous system.

Under normal circumstances, sensations are generated only upon stimulation of the end of the nerve fiber that is called receptor. Then sensory nerve fibers relay this information to the Spinal Cord/Brain, and cells in the Spinal Cord/Brain, in turn, relay this information to the brain.

 

These sensory neurons can detect temperature change only if they have THERMOCEPTORS ( receptors that are able to detect changes in temperature.)

                                                                

However, a distinct subset of sensory neurons are thought to directly sense changes in thermal energy through their termini in the skin. Very little is known about the molecules that mediate thermoreception by these neurons.

 

Vanilloid Receptor 1 (VR1), a member of the TRP family of channels, is activated by noxious heat. Here we describe the cloning and characterization of TRPM8, a distant relative of VR1.

TRPM8 is specifically expressed in a subset of pain- and temperature-sensing neurons.

 

Cells overexpressing the TRPM8 channel can be activated by cold temperatures and by a cooling agent, menthol. Our identification of a cold-sensing TRP channel in a distinct subpopulation of sensory neurons implicates an expanded role for this family of ion channels in somatic sensory detection.

 

                                                    

 

The above movie shows the endings of a sensory neuron where Menthol is affecting its TRPM8 channels that will later sends a nervous message notifying the brain of a cold sensation!