Comparing a map of the neurons in a nematode worm — the connectome — with a map of how signals travel across those neurons has revealed a surprising number of differences, suggesting that the structure of the brain alone doesn’t explain how it works
Category: neuroscience – Page 193
A new look at how the brain works reveals that wiring isn’t everything
How a brain’s anatomical structure relates to its function is one of the most important questions in neuroscience. It explores how physical components, such as neurons and their connections, give rise to complex behaviors and thoughts. A recent study of the brain of the tiny worm C. elegans provides a surprising answer: Structure alone doesn’t explain how the brain works.
C. elegans is often used in neuroscience research because, unlike the incredibly complex human brain, which has billions of connections, the worm has a very simple nervous system with only 302 neurons. A complete, detailed map of every single one of its connections, or brain wiring diagram (connectome), was mapped several years ago, making it ideal for study.
In this research, scientists compared the worm’s physical wiring in the brain to its signaling network, how the signals travel from one neuron to another. First, they used an electron microscope to get a detailed map of the physical connections between its nerve cells. Then, they activated individual neurons with light to create a signaling network and used a technique called calcium imaging to observe which other neurons responded to this stimulation. Finally, they used computer programs to compare the physical wiring map and the signal flow map, identifying any differences and areas of overlap.
IQ appears to affect ability to listen in noisy settings
You’re in a bustling café with a friend. The din is making it hard to tune in to the conversation. The scenario might suggest you’d benefit from a hearing aid. On the other hand, new research suggests that speech-perception difficulty might relate to your cognitive ability.
In a study of three groups—individuals with autism, fetal alcohol syndrome and a “neurotypical” control group—researchers found that cognitive ability was significantly associated with how well the participants, all with typical hearing, processed speech in noisy environments.
“The relationship between cognitive ability and speech-perception performance transcended diagnostic categories. That finding was consistent across all three groups,” said the study’s lead investigator, Bonnie Lau. She is a research assistant professor in otolaryngology–head and neck surgery at the University of Washington School of Medicine and directs lab studies of auditory brain development.
Why do we remember some life moments—but not others?
Some memories are easy to recall—lush with detail, fresh as the moment itself. Others are more tenuous, like faded sketches, and the most stubborn ones can refuse to resurface at all. Why do our brains enshrine some memories so indelibly, and let others slip away?
A new Boston University study has a potential answer, suggesting that memories of mundane moments are given extra sticking power if they become connected to a significant event—something surprising, rewarding, or carrying an emotional punch. Watch your Powerball numbers cash in, for example, and you’re likely to remember what you were doing in the moments before, however unremarkable and unmemorable they might have otherwise been.
The findings, published in Science Advances, could potentially lead to improved treatments for people with memory problems or even help students retain tricky concepts.
Rising Cognitive Disability as a Public Health Concern Among US Adults
From 2013 to 2023, rates of cognitive disability nearly doubled among U.S. adults under 40.
Cognitive disability includes self-reported serious difficulty concentrating, remembering, or making decisions.
Rates are highest among people with chronic diseases or lower household incomes.
Background and Objectives.
Oral bacteria linked to Parkinson’s via the gut-brain axis
Korean researchers have uncovered compelling evidence that oral bacteria, once colonized in the gut, can affect neurons in the brain and potentially trigger Parkinson’s disease.
The joint research team, led by Professor Ara Koh and doctoral candidate Hyunji Park of POSTECH’s Department of Life Sciences, together with Professor Yunjong Lee and doctoral candidate Jiwon Cheon of Sungkyunkwan University School of Medicine, collaborated with Professor Han-Joon Kim of Seoul National University College of Medicine.
They have identified the mechanism by which metabolites produced by oral bacteria in the gut may trigger the development of Parkinson’s disease. The findings were published online in Nature Communications.
Groove is in the brain: Music supercharges brain stimulation
Music affects us so deeply that it can essentially take control of our brain waves and get our bodies moving. Now, neuroscientists at Stanford’s Wu Tsai Neurosciences Institute are taking advantage of music’s power to synchronize brain waves to boost the effectiveness of a technique called transcranial magnetic stimulation (TMS), a promising tool for both basic brain research and treating neuropsychiatric disorders.
Specifically, institute affiliate Jessica Ross and colleagues used TMS pulses to induce movements in people’s hands—a common testing ground for new ideas in the field. By carefully timing those pulses to music, the team found they could double the impact of TMS.
“Because there’s this really strong connection to movement, music can engage motor pathways in the brain. If you’re listening to a certain kind of rhythm, there are going to be very specific times at which your brain is most ready for the TMS effect,” said Ross, an instructor in the Department of Psychiatry and Behavioral Sciences at Stanford Medicine.
A more precise CRISPR platform enables large-scale gene screening in live mouse brains
Over the past few decades, biomedical researchers and neuroscientists have devised increasingly advanced techniques to study and alter neurophysiological processes. These include CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats), a sophisticated tool to edit specific genes in some animals, including mice, rats, zebrafish and fruit flies.
Researchers at University of California, San Francisco led by Martin Kampmann recently introduced a more precise CRISPR screening platform that can be applied directly in living tissue, enabling the screening of a larger number of genes at once. The new technique, called CRISPR screening by AAV episome sequencing (CrAAVe-seq), was introduced in a paper published in Nature Neuroscience.
“Human cell-based systems are valuable but cannot fully capture the complexity of the brain,” Biswa Ramani, co-first author of the paper, told Medical Xpress. “Mice often remain the most effective model for many neurological diseases because their brains preserve the diversity and organization of cell types that cannot be replicated in a dish.”