The flagellar tails of bacteria rotate clockwise or counterclockwise because of active mechanical forces that pressure the individual ‘teeth’ of a gear to cooperate. This revises a decades-old model of how bacteria tails switch their rotational direction. The study, led by scientists at the Flatiron Institute, appears in Nature Physics.

We've all been there…

You know you need to make that complaint phone call, but you cannot bring yourself to dial. Or there is a project your demanding boss assigned, and even though you know you should start, you just…can't. You’re stuck at the starting line, caught in that all-too-familiar sense of motivational paralysis.

Why is it so hard to just get started?

Now, scientists at Kyoto University's Institute for the Advanced Study of Human Biology (WPI-ASHBi) have discovered what's happening in the brain during these frustrating moments. The research team conducted research on macaque monkeys and identified a specific brain circuit that acts like a "motivation brake": a neural pathway connecting two brain regions (the ventral striatum and ventral pallidum) that kicks in when we are confronted with tasks that come with negative consequences. When the scientists temporarily disabled this circuit, the motivational brake released: tasks that were once avoided suddenly became approachable. This discovery may help explain why, for some people (such as those living with depression), starting even simple tasks can feel impossibly hard. By identifying the brain "switch" behind this motivational paralysis, researchers may be one step closer to developing new treatments that help people overcome this invisible barrier.

The research is led by Dr. Ken-ichi Amemori, Dr. Jungmin Oh, and Dr. Satoko Amemori, with Dr. Masahiko Takada (Professor, Center for Human Behavior Evolution Research; currently Professor Emeritus), Dr. Ken-ichi Inoue (Assistant Professor; currently Associate Professor at Nagoya City University), and Dr. Kei Kimura (Assistant Professor, Tohoku University). The findings of this study will be published online in Current Biology at 11:00 a.m. on January 9, 2026 (EST; January 10, 1:00 a.m. JST).

Alzheimer’s disease (AD) is a serious neurodegenerative disease largely affecting older adults. Apart from age, it also shows sex-based differences, with women being more at risk. However, the origin of these differences remains unknown. While bone morphogenetic proteins (BMPs) play an important role in adult neurogenesis, their role in AD remains elusive. To address this, researchers have investigated sex-based differences and role of BMP signaling in neurogenesis in AD mice models, uncovering novel therapeutic targets

An international group of researchers says that biodiversity conservation and scientific research are not benefiting from the vast knowledge about the world’s plants held by botanic gardens, because of fragmented data systems and a lack of standardisation. They call for a unified and equitable global data system for living collections to transform how the world’s botanic gardens manage and share information. This would enable them to work together as a ‘meta-collection’ to strengthen scientific research and conservation efforts.

When the cell’s recycling stations, the lysosomes, start leaking, it can become dangerous. Toxic waste risks spreading and damaging the cell. Now, researchers at Umeå University have revealed the molecular sensors that detect tiny holes in lysosomal membranes so they can be quickly repaired – a process crucial for preventing inflammation, cell death, and diseases such as Alzheimer’s.

Exercise restores a key cellular balance in ageing muscles, helping them stay stronger and more resilient.