Krista Conger writes about a Stanford Medicine study showing the human brain consists of two distinct organs that evolved independently over hundreds of millions of years. The forebrain and midbrain arise from one progenitor cell, while the hindbrain (brain stem) arises from a completely separate one, overturning the long-held assumption that a single progenitor cell gives rise to the entire brain. The finding explains why scientists have struggled for decades to grow hindbrain neurons in the lab and opens new avenues for studying diseases like spinal muscular atrophy and ALS.
- Published in *Nature Neuroscience*; Kyle Loh is senior author, with graduate students Carolyn Dundes and Rayyan Jokhai as co-first authors
- The same two-origin pattern was identified in chickens, zebrafish, and acorn worms — tiny ocean-floor creatures that share a distant common ancestor with humans
- The hindbrain contains the hunger-regulating circuits targeted by weight-loss drugs like semaglutide
- Published in *Nature Neuroscience*; Kyle Loh is senior author, with graduate students Carolyn Dundes and Rayyan Jokhai as co-first authors
- The same two-origin pattern was identified in chickens, zebrafish, and acorn worms — tiny ocean-floor creatures that share a distant common ancestor with humans
- The hindbrain contains the hunger-regulating circuits targeted by weight-loss drugs like semaglutide
A new study using fMRI scans on children as young as three has revealed that language processing and Theory of Mind (the ability to understand others' feelings) originate from completely separate, non-overlapping brain regions. While both functions involve the superior temporal lobe, language is localized in the left hemisphere and empathy in the right. This research challenges previous theories by showing that these cognitive skills do not emerge from a shared source and become specialized over time; instead, they possess a discrete architecture from very early development.
* Hemispheric separation of language (left) and Theory of Mind (right).
* Neural distinction is present in toddlers and remains stable throughout childhood.
* Unique connectivity fingerprints prove the two systems communicate with the rest of the brain differently.
* Adult brains show increased integration between these networks to support complex social interactions.
* Hemispheric separation of language (left) and Theory of Mind (right).
* Neural distinction is present in toddlers and remains stable throughout childhood.
* Unique connectivity fingerprints prove the two systems communicate with the rest of the brain differently.
* Adult brains show increased integration between these networks to support complex social interactions.
Researchers at Kyushu University have discovered that adolescent brain development involves more than just the traditional process of synaptic pruning.
Using super-resolution microscopy, the team identified previously unknown high-density clusters of synapses, or hotspots, that form specifically during adolescence in the cerebral cortex. This discovery suggests that while the brain is indeed trimming excess connections, it is simultaneously building new, dense neural structures.
* Challenges the singular focus on synaptic pruning during adolescence.
* Identifies specific high-density dendritic spine hotspots in Layer 5 neurons.
* Suggests that impaired formation of these hotspots, rather than just excessive pruning, may contribute to schizophrenia.
* Provides a new perspective on how cortical circuits mature during developmental windows.
Using super-resolution microscopy, the team identified previously unknown high-density clusters of synapses, or hotspots, that form specifically during adolescence in the cerebral cortex. This discovery suggests that while the brain is indeed trimming excess connections, it is simultaneously building new, dense neural structures.
* Challenges the singular focus on synaptic pruning during adolescence.
* Identifies specific high-density dendritic spine hotspots in Layer 5 neurons.
* Suggests that impaired formation of these hotspots, rather than just excessive pruning, may contribute to schizophrenia.
* Provides a new perspective on how cortical circuits mature during developmental windows.
