Hybrid Brain Cell Discovered: Implications for Neuroscientific Research and Potential Treatments

Friday - September 8 2023, 01:25 UTC - 1 year ago

Researchers have discovered a hybrid brain cell, bridging the gap between neurons and astrocytes. This cell can release neurotransmitters, and has potential implications for epilepsy, memory consolidation, and other treatments. The research was co-directed by the University of Lausanne and Wyss Center for Bio and Neuroengineering in Geneva. An imaging technique known as single-cell transcriptomics was used to cluster the molecular content of the astrocytes.

Researchers have discovered a new hybrid brain cell, bridging the gap between neurons and astrocytes. This cell can release neurotransmitters and may influence conditions like epilepsy and memory consolidation, offering promising paths for neuroscientific research and potential treatments.

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.

By identifying a new cell type with the characteristics of an astrocyte and expressing the molecular machinery necessary for synaptic transmission, neuroscientists from the Department of Basic Neurosciences of the Faculty of Biology and Medicine of the University of Lausanne (UNIL) and the Wyss Center for Bio and Neuroengineering in Geneva put an end to years of controversy.

The Key to the Puzzle .

To confirm or refute the hypothesis that astrocytes, like neurons, are able to release neurotransmitters, researchers first scrutinized the molecular content of astrocytes using modern molecular biology approaches. Their goal was to find traces of the machinery necessary for the rapid secretion of glutamate, the main neurotransmitter used by neurons.

"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.

New Functional Cells .

Next, neuroscientists tried to find out if these hybrid cells were functional, that is, able to actually release glutamate with a speed comparable to that of synaptic transmission. To do this, the research team used an advanced imaging technique that could visualize glutamate released by vesicles in brain tissues and in living mice.

"We have identified a subgroup of astrocytes responding to selective stimulations with rapid glutamate release, equivalent in speed to that of neurons, although at a much lower intensity. This response enables communication between neighboring cells, but requires a substantial amount of cells to form an appreciable signal," explains Klaas Priebe, researcher at the Wyss Center and co-director of the study.