Researchers identified a region of the thalamus that predicts and nullifies the effects of movement on visual perception, enabling precise representation of the world.
Category: neuroscience – Page 212
AI identifies PHGDH as amyloid pathology driver in Alzheimer’s disease
Insomnia, depression, and anxiety are the most common mental disorders. Treatments are often only moderately effective, with many people experiencing returning symptoms. This is why it is crucial to find new leads for treatments. Notably, these disorders overlap a lot, often occurring together. Could there be a shared brain mechanism behind this phenomenon?
Siemon de Lange, Elleke Tissink, and Eus van Someren, together with their colleagues from the Vrije Universiteit Amsterdam, investigated brain scans of more than 40,000 participants from the UK Biobank. The research is published in the journal Nature Mental Health.
Tissink says, “In our lab, we explore the similarities and differences between insomnia, anxiety, and depression. Everyone looks at this from a different perspective: some mainly look at genetics and in this study, we look at brain scans. What aspects are shared between the disorders, and what is unique to each one?”
How morphogens steer early brain development by guiding stem cell gene activity
Just a few weeks after conception, stem cells are already orchestrating the future structure of the human brain. A new Yale-led study shows that, early in development, molecular “traffic cops” known as morphogens regulate the activation of gene programs that initiate stem cells’ differentiation into more specialized brain cells.
The Yale team found that sensitivity to these signaling morphogens can vary not only between stem cells from different donors, but between stem cells derived from the same individual.
“This is a new chapter in understanding how we develop and how development can be influenced by genomic changes between people and by epigenetic modifications within individuals,” said Flora Vaccarino, the Harris Professor in the Child Study Center at the Yale School of Medicine (YSM) and co-senior author of the research, published in the journal Cell Stem Cell.
How fruit flies’ neurons spot tiny visual errors to keep them flying straight
When a fruit fly is navigating straight forward at high speed, why does it know that it’s not straying off course? Because as long as the fly moves directly forward, the visual scene shifts from front to back in a near-perfect mirror image across both retinas—generating, in other words, a symmetrical visual motion pattern. This pattern, known as “optic flow,” provides a powerful cue for detecting self-motion and maintaining direction.
Moreover, at high speeds, as soon as the fly starts deviating from its straight-ahead course even slightly, the optic flow becomes less symmetrical. But the high level of translational symmetry due to the fly’s high-speed forward motion could mask smaller binocular asymmetries caused by slight rotational inflections in its trajectory.
Therefore, detecting such “errors” and correcting them at the motor level is not trivial and must happen very quickly. Only then will the fly ensure it continues to move straight forward, as intended.
New insight into the neurobiological roots of being a ‘morning person’ or ‘night owl’
Human beings exhibit marked differences in habits, lifestyles and behavioral tendencies. One of these differences, known as chronotype, is the inclination to sleep and wake up early or alternatively to sleep and wake up late.
Changes in society, such as the introduction of portable devices and video streaming services, may have also influenced people’s behavioral patterns, offering them further distractions that could occupy their evenings or late nights. Yet past studies have found that sleeping and waking up late is often linked to a higher risk of being diagnosed with mental health disorders, such as depression and anxiety disorders, as well as poorer physical health.
Understanding the neurobiological underpinnings of humans’ chronotypes, as well as the possible implications of being a so-called “morning person” or “night owl,” could thus be beneficial. Specifically, it could inform the development of lifestyle interventions or medical treatments designed to promote healthy sleeping patterns.
Chimeric brain models can help bridge the gap between animal studies and human neurological disorders
A specialized model used by researchers is becoming a valuable tool for studying human brain development, diseases and potential treatments, according to a team of scientists at Rutgers University-New Brunswick.
Known as chimeric brain models, these laboratory tools provide a unique way to understand human brain functions in a living environment, which may lead to new and better therapies for brain disorders, researchers said in a review article in Neuron.
Scientists create models by transplanting human brain cells culled from stem cells into the brains of animals such as mice, thereby creating a mix of human and animal brain cells in the same brain. This environment is closer to the complexity of a living human brain than what can be simulated in a petri dish study.