The Award:

• The Nobel Assembly has decided to award the 2021 Nobel prize in physiology or medicine jointly to David Julius and Ardem Patapoutianof USA “for their discoveries of receptors for temperature and touch”.

Importance of their work

• Our ability to sense heat, cold and touch is essential for survival and support our interactions with the world around us. These researchers have discovered the molecular mechanism by which our body senses touch and temperature. This has opened the field for a lot of practical chemistry through which individual cells and pathways can be activated or tweaked to pacify pain or sensation.
• Prior to the discoveries by David Julius and ArdemPatapoutian, understanding of our nervous system was contained by:- how temperature and mechanical stimuli are converted into to electrical impulses in the nervous system?

Work of David Julius

• Capsaicin(8-methyl-N-Vanillyl- 6-noneamide), is the active component of chili peppers. It generates the burning sensation when we eat spicy food. When capsaicin acts on sensory nerves it induces ionic currents along a membrane. In the late 1990, Professor Julius started a project to identify a nerve receptor for capsaicin. He looked for a gene that could induce a response to capsaicin in cells that usually wouldn’t react to it. He found a novel ion channel protein, called TRPV1.

TRP- transient receptor potential VR1- Vanilloid receptor 1

• It was found that TRPV1 got activated above 40 degree centigrade, which is close to the body’s pain threshold.

Work of ArdemPatapoutian

• Patapoutian was working on how pressure and force affects cells. Patapoutian and Julius’s approach was similar. Of the 72 genes identified, Piezo1 was able to trigger sensitivity to mechanical force. Via Piezo1, a
  second gene, Piezo2 was discovered.
• Piezo1 and Piezo2 areion channels that are directly activated by the exertion of pressure on cell membranes.
• Piezo2 played a key role in physiology; regulate blood pressure respiration and urinary bladder control.

Relevance of these discoveries

• These discoveries have allowed insight into the structure of these pain and temperature sensors. Now the challenge for pain relieving drugs is to precisely target the region without disturbing other regions.