A recent survey released by the interdisciplinary group Braingeneers, UC Santa Cruz and UC San Francisco in the United States, challenges the traditional paradigm of neuroscience that considers neurons as fixed and unchanging after their initial brain formation.
Brain cells responsible for the transmission of signals (electrical and chemical impulses) by the body, neurons were so far considered permanent, that is, each of its specific types, such as motor, sensory or interneuronium neuron, had a definite and unalterable cell identity.
But, the identity of the neuronal subtype can be much more flexible than imagined. Working with organoids, 3D models of brain tissue, the authors tested in vitro how neurons develop and adapt.
The findings not only revealed an unexpected type of plasticity of destination, but also offered unpublished insights “on how different neuron subtypes influence brain function, and can play a role in neurodevelopment disorders,” the study says.
For the first author of the article, Mohammed Mostajo-Radji, researcher at the UC Santa Cruz Genomics Institute, the new parameter “It’s making us rethink how neurons are really made and maintained, and the influence of the environment in this process”.
Creating unpublished models of brain cells
The cerebral cortex has two main types of neurons: 80% excitatory and 20% inhibitory. Of these, 60% are positive for parvalbumin (PV+), a protein that binds to calcium and is associated with neural processes involving ultra -rare transmission of information.
In addition to its role in the brain’s ability to adapt and change, PV+ neurons are linked to disorders such as autism and schizophrenia. , can undermine cognitive processes (attention, memory, reasoning) and sensory.
This makes these inhibitory interneurons very important for research on brain development and neurological and psychiatric diseases. For Mostajo-Radji, the key to success in the unprecedented production of these laboratory neurons was the use of 3D structures, more like the real brain.
Efficient cell development in three -dimensional environments showed that these structures are essential to replicate complex biological processes. In addition to questioning traditional methods, research also opens the way to reproduce other non -viable models in flat cultures.
The production of these positive laboratory parvalbumin neurons allows advances in the study of diseases and the creation of more accurate brain models. “Now we can make a more realistic model of the brain”says Mostajo-Radji in a release.
Researching new identity changes
But the tests didn’t stop there. To reinforce their hypotheses, the researchers added another type of inhibitory neuron, Somatostatin shamanto the 3D organoid model. Under these conditions, they noticed some somatostatin neurons turning into PV+.
Even without having the exact understanding of the genetic and environmental conditions involved in the transition, the authors claim that the discovery by themselves opens the possibility that the changes in neuronal identity occurred in vitro They can also occur in living cells of the brain.
Betting on this possibility, Mosta-Radji proposes that “perhaps there is a process. It is an exciting window that we should explore, and some other laboratories across the country are beginning to think the same way.”
Although they already have some clues about which genetic roads may be at stake in the transition between neuronal subtypes, researchers also intend to deepen excitatory cell investigation to understand their role in the fate of inhibitory cells.
The newly discovered capacity to recreate brain plasticity in 3D organoids opens new research fronts on brain development, the emergence of neurological diseases and possible cell reprogramming therapies using the patient’s own cells to regenerate damaged parts.
