Alice Rossi and Sampurna Chakrabarti

Two postdocs in the Lewin Lab earn fellowship

Alice Rossi and Sampurna Chakrabarti have both received a Humboldt Research Fellowship. The scientists are investigating the molecular processes that occur during basic physiological functions, such as the perception of touch – or as part of the unique survival strategies of naked mole-rats.

At the Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Dr. Alice Rossi is investigating why African naked mole-rats can withstand significantly lower oxygen levels than other mammals without suffering permanent organ damage. Her colleague Dr. Sampurna Chakrabarti is measuring the nerve cell activity that causes people to experience touch and pain.

The Alexander von Humboldt Foundation is now supporting both research projects with funding for two years. In addition to financing the two postdoctoral positions, the fellowships include funds for laboratory costs, the opportunity to take a German course, and participation in various Bayer Foundation seminars and networking events.

Cell metabolism during oxygen deficiency

Alice Rossi

Rossi’s work focuses on cell organelles – the mitochondria. These power generators produce the energy required for all cellular functions. If mammals do not take in enough oxygen from the air, their cells become undernourished and die. This can leave organs like the heart or brain with permanent damage. This mechanism is similar in all mammals – with one exception: naked mole-rats. The rodents live in underground caves, where there is little oxygen and a lot of carbon dioxide. “These animals have developed metabolic adaptations that allow them to fully recover from long periods of oxygen deprivation without their organs being affected,” explains Rossi. To achieve this, the rodents switch their cell metabolism from glucose to fructose and simultaneously turn off their mitochondria. This enables the cells to continue to function even in the absence of oxygen.

Rossi now wants to compare how mitochondria work with a normal oxygen supply and with a lack of oxygen. To do this, she is looking at the morphology and dynamics of mitochondria using advanced imaging techniques and measuring the oxygen consumption rate – one of the most important indices of their activity. Her findings could lead to the discovery of new therapeutic approaches in the treatment of strokes and heart failure. Since February 2019, the researcher has been working in the Molecular Physiology of Somatic Sensation Lab. Prior to coming to Berlin, she wrote her doctoral thesis on mitochondrial bioenergetics in Alzheimer’s disease at the University of Padua. Her fellowship is also supported by the Bayer Science and Education Foundation, her project will begin in March 2021.

The electrophysiology of somatic-sensory perception

Sampurna Chakrabarti

The human body can perceive a wide range of touch sensations. The sensation of a gentle stroking or a painful pinch is the result of ion channels in the body converting mechanical stimuli, such as pressure, into electrical signals. Researchers have already discovered a few of these ion channels, but they assume that many more exist. “I am interested in identifying the as-yet-undiscovered ion channels that are involved in the sense of touch,” says Chakrabarti, who will start the project in December 2020.

The Lewin group, in which Chakrabarti is a member of since the beginning of the year, has been investigating the perception of pain in mammals for several years. The postdoc suspects that at some point in the future, these unknown molecules and ion channels could be used for targeted pain relief. Chakrabarti’s findings may open new possibilities for the treatment of patients with chronic pain.

Chakrabarti is primarily using electrophysiological tests to identify unknown ion channels. She had previously researched pain in osteoarthritis and measured the electrical activity of nerves as part of her doctoral thesis at the University of Cambridge. More than 200 years ago, Alexander von Humboldt used electrophysiology to investigate the activity of nerve and muscle cells – now, Chakrabarti and Rossi are able to fund their research with the fellowship that bears his name.

Further information

Humboldt Fellowships for Postdocs