In a significant scientific breakthrough, researchers from the University of Lausanne in Switzerland have reported the discovery of a novel type of brain cell, revealed in a study published in the journal Nature. This newfound cell exhibits characteristics that bridge the gap between neurons and astrocytes, the non-neuronal glial cells crucial for supporting and safeguarding neurons in the brain and spinal cord.

The researchers identified these hybrid cells within specific regions of the brain, in contrast to the usual dispersed distribution of astrocytes. Notably, these hybrid cells demonstrated the ability to produce the neurotransmitter glutamate, a key regulator of neuronal activity and excitation levels.

Andrea Volterra, the senior author of the paper and a neuroscientist at UNIL, expressed enthusiasm about the discovery’s research potential. “In between neurons and astrocytes, we now have a new kind of cell at hand. Its discovery opens up immense research prospects,” Volterra stated, adding that future investigations would explore its potential role in protecting against memory impairment in Alzheimer’s disease and its involvement in various brain regions and pathologies.

Astrocytes, typically responsible for regulating glutamate levels within the central nervous system, play a vital role in maintaining proper neuronal function. Glutamate, a neurotransmitter with far-reaching implications, activates neurons, facilitates communication, and contributes significantly to learning and memory processes by strengthening neural connections.

Neuroscientists have long speculated that astrocytes might actively engage in neural communication and information processing by releasing glutamate. This hypothesis raised questions about whether astrocytes indeed release glutamate in this manner, as earlier studies yielded mixed results.

In the current study, researchers investigated potential variations among astrocytes in the brain. They utilized a molecular biology technique called single-cell transcriptomics to examine the gene expression profiles of individual cells within mouse brains. This approach led to the discovery of a subset of astrocytes capable of releasing glutamate.

Ludovic Telley, a study co-author and assistant professor of neuroscience at UNIL, noted the identification of specialized proteins crucial for the function of transporting glutamate out of these astrocytes and facilitating rapid communication with other cells.

To assess the impact of these hybrid cells on neural communication and information processing, the researchers employed advanced imaging techniques to observe glutamate release in live mouse brain tissue. The results confirmed that hybrid cells could release glutamate swiftly in specific areas resembling sites of neuronal communication.

Further experimentation involved the genetic removal of specialized proteins, known as vesicular glutamate transporters (VGLUT), used by these specialized astrocytes. This intervention interfered with neural circuits like the cortico-hippocampal circuit, impairing the memories of the mice.

While this discovery holds promise for advancing our understanding of brain function and potential applications in neurological conditions, it is essential to note that the findings are primarily based on mouse brain models. Further validation through human-based studies will be necessary.

In the future, researchers aspire to map the distribution of these unique astrocytes throughout the central nervous system and delve deeper into their roles in various brain disorders, potentially opening new avenues for treatment.

By Impact Lab