Introducing the brain: a new brain cell (Introduction)

by David Turell , Wednesday, September 06, 2023, 16:38 (442 days ago) @ David Turell

A glial cell that transmites:

https://medicalxpress.com/news/2023-09-discovery-kind-cell-neuroscience.html

"A research team from University of Lausanne (UNIL) and the Wyss Center, has discovered a new type of cell essential for brain function. Hybrid in composition and function, in between the two types of brain cells known so far—the neurons and the glial cells—these cells of a new order are present in several brain regions in mice and humans.

"The study published in the journal Nature shows that these cells promote the ability to memorize, the brain control of movements, and contrast the insurgence of epileptic seizures.

"Neuroscience is in great upheaval. The two major families of cells that make up the brain, neurons and glial cells, secretly hid a hybrid cell, halfway between these two categories. For as long as neuroscience has existed, it has been recognized that the brain works primarily thanks to the neurons and their ability to rapidly elaborate and transmit information through their networks.

"To support them in this task, glial cells perform a series of structural, energetic and immune functions, as well as stabilize physiological constants. Some of these glial cells, known as astrocytes, intimately surround synapses, the points of contact where neurotransmitters are released to transmit information between neurons.

"This is why neuroscientists have long suggested that astrocytes may have an active role in synaptic transmission and participate in information processing. However, the studies conducted to date to demonstrate this have suffered from conflicting results and have not reached a definitive scientific consensus yet.

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"'The precision allowed by single-cell transcriptomics approaches enabled us to demonstrate the presence in cells with astrocytic profile of transcripts of the vesicular proteins, VGLUT, in charge of filling neuronal vesicles specific for glutamate release. These transcripts were found in cells from mice, and are apparently preserved in human cells. We also identified other specialized proteins in these cells, which are essential for the function of glutamatergic vesicles and their capacity to communicate rapidly with other cells," says Ludovic Telley, Assistant professor at UNIL, co-director of the study.

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"'We have identified a subgroup of astrocytes responding to selective stimulations with rapid glutamate release, which occurred in spatially delimited areas of these cells reminiscent of synapses," says Andrea Volterra, honorary professor at UNIL and visiting faculty at the Wyss Center, co-director of the study.

"In addition, this glutamate release exerts an influence on synaptic transmission and regulates neuronal circuits. The research team was able to demonstrate this by suppressing the expression of VGLUT by the hybrid cells.

"'They are cells that modulate neuronal activity, they control the level of communication and excitation of the neurons," says Roberta de Ceglia, first author of the study and senior researcher at UNIL. And without this functional machinery, the study shows that long-term potentiation, a neural process involved in the mechanisms of memorization, is impaired and that the memory of mice is impacted.

"The implications of this discovery extend to brain disorders. By specifically disrupting glutamatergic astrocytes, the research team demonstrated effects on memory consolidation, but also observed links with pathologies such as epilepsy, whose seizures were exacerbated. Finally, the study shows that glutamatergic astrocytes also have a role in the regulation of brain circuits involved in movement control and could offer therapeutic targets for Parkinson's disease."

Comment: The brain becomes even more complex.