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Mathematician Bernhard Riemann was born #OTD in 1826.


Bernhard Riemann was another mathematical giant hailing from northern Germany. Poor, shy, sickly and devoutly religious, the young Riemann constantly amazed his teachers and exhibited exceptional mathematical skills (such as fantastic mental calculation abilities) from an early age, but suffered from timidity and a fear of speaking in public. He was, however, given free rein of the school library by an astute teacher, where he devoured mathematical texts by Legendre and others, and gradually groomed himself into an excellent mathematician. He also continued to study the Bible intensively, and at one point even tried to prove mathematically the correctness of the Book of Genesis.

Although he started studying philology and theology in order to become a priest and help with his family’s finances, Riemann’s father eventually managed to gather enough money to send him to study mathematics at the renowned University of Göttingen in 1846, where he first met, and attended the lectures of, Carl Friedrich Gauss. Indeed, he was one of the very few who benefited from the support and patronage of Gauss, and he gradually worked his way up the University’s hierarchy to become a professor and, eventually, head of the mathematics department at Göttingen.

One of the brain’s most celebrated qualities is its adaptability. Changes to neural circuits, whose connections are continually adjusted as we experience and interact with the world, are key to how we learn. But to keep knowledge and memories intact, some parts of the circuitry must be resistant to this constant change.

“Brains have figured out how to navigate this landscape of balancing between stability and flexibility, so that you can have new learning and you can have lifelong memory,” says neuroscientist Mark Harnett, an investigator at MIT’s McGovern Institute for Brain Research.

In research published in Cell Reports, Harnett and his team show how individual neurons can contribute to both parts of this vital duality. By studying the synapses through which pyramidal neurons in the brain’s sensory cortex communicate, they have learned how the cells preserve their understanding of some of the world’s most fundamental features, while also maintaining the flexibility they need to adapt to a changing world.

Developing large-scale neural network models that mimic the brain’s activity is a major goal in the field of computational neuroscience. Existing models that accurately reproduce aspects of brain activity are notoriously complex, and fine-tuning model parameters often requires significant time, intuition, and expertise.

New published research from an interdisciplinary group of researchers primarily based at Carnegie Mellon University and the University of Pittsburgh presents a novel solution to mitigate some of these challenges. The machine learning-driven framework, Spiking Network Optimization using Population Statistics (SNOPS), can quickly and accurately customize models that reproduce activity to mimic what’s observed in the .

The work is published in the journal Nature Computational Science.

Scientists have discovered a mutation in SARS-CoV-2, the virus that causes COVID-19, that plays a key role in its ability to infect the central nervous system. The findings may help scientists understand its neurological symptoms and the mystery of “long COVID,” and they could one day even lead to specific treatments to protect and clear the virus from the brain.

The new collaborative study between scientists at Northwestern University and the University of Illinois-Chicago uncovered a series of mutations in the SARS-CoV-2 spike protein (the outer part of the virus that helps it penetrate cells) that enhanced the virus’s ability to infect the brains of mice.

“Looking at the genomes of viruses found in the brain compared to the lung, we found that viruses with a specific deletion in spike were much better at infecting the brains of these animals,” said co-corresponding author Judd Hultquist, assistant professor of medicine (infectious diseases) and microbiology-immunology at Northwestern University Feinberg School of Medicine. “This was completely unexpected, but very exciting.”