Just this past September, Italian neuroscientist Andrea Voltra announced the discovery of a new type of cell in the human brain.
A new type of cell has been discovered in the human brain. (pixabay)
According to Voltra’s paper published in the journal Nature, this is a new type of cell that is critical to brain function. The cells are found in multiple areas of the mouse and human brain and exhibit mixed properties in structure and function. Additionally, these cells have enhanced effects on memory and the brain’s control of movement.
For years, Voltra has been telling his students the story of Santiago Ramón Cajal, the father of modern neurology.
In 1888, Cajal established a laboratory in his residence in Barcelona, Spain, and began studying slices of human brains under a microscope. He obtained donated organs from a nearby hospital. Once, while observing a brain slice, he saw an “intricate jungle” on the other side of the microscope lens.
When he studied this “jungle” in depth, he finally came up with the new view that “the brain is also composed of single cells”, among which neurons are the “protagonists” of thinking.
Now, Voltra’s new findings have attracted a lot of attention from the neuroscience community. The US Daily Science website published an article saying that the discovery “shakes the foundation of neuroscience.”
The two main families of cells that make up the brain are neurons and glia.
The “brain jungle” or neuron density Cajal discovered was unexpected. According to Spanish newspaper El Pais, there are approximately 86 billion neurons (commonly known as gray matter) connected to trillions of synapses in the brain, which weighs only 1.5 kilograms. Previously, the scientific community generally believed that the brain was a dispersed, physically interconnected network. Cajal showed that neurons communicate with each other by “kissing” synapses.
Liu Shiping, chief scientist and researcher of brain science at the Shenzhen BGI Life Sciences Institute, told a reporter from Science and Technology Daily that these synapses are like “communication stations.”
“The main responsibility of neurons is to transmit neural signals, including the generation and conduction of electrical signals, as well as connections with other neurons.” Liu Shiping said, “All our conscious or unconscious activities generally rely on neurons. For signal conduction and processing, neurons are also very energy-consuming cells.”
It is generally believed that neurons are surrounded by glial cells. Glial cells have multiple functions, including maintaining the chemical environment of neurons, providing nutrients, supporting nerve signal transmission and processing, and participating in immune responses. One type of glial cell is named an astrocyte because of its star-like shape.
In addition, Liu Shiping introduced that the ratio of neurons and glial cells in the brain is roughly 1:1. In addition to these two major cell families, the brain also contains some other types of cells, such as microglia.
New type of cells can communicate with other cells (photoAC)
The new type of cell discovered this time is a hybrid cell between these two brain cell families. It does not belong to the two typical categories of neurons or glial cells.
When one neuron is electrically stimulated, it releases chemicals called neurotransmitters, such as glutamate, into the gap with another neuron, triggering synaptic transmission of electrical to chemical signals to the next neuron. of activation. This ability is widely believed to be unique to neurons.
Now, Voltra’s team has announced their discovery that some glial cells can actually communicate with other cells through synaptic-like transmission. They named these new cells “glutamatergic astrocytes” and called them “hybrid cells.”
Liu Shiping said that this cell should not be called the “third type” cell family in the brain. To be precise, it belongs to a subpopulation of astrocytes. The so-called “hybrid cell” is because although it is a type of glial cell, it can perform some functions of neurons.
Menéndez de la Prida, a neuroscientist at the Cajal Institute in Madrid, Spain, says this subpopulation of astrocytes has part of the neuronal molecular machinery necessary to release glutamate. Information transfer between neurons is very fast, taking only a few milliseconds, or up to tens of milliseconds if synaptic transmission occurs between several neurons in a chain (polysynapse). In contrast, astrocytes can take several seconds to transmit information. The response time of this subpopulation of astrocytes is less than one second, which is closer to a polysynaptic response.
Prida believes that this is “a transcendent discovery” that will change our understanding of brain function and related diseases.
Research shows that these cells regulate neuronal activity and control the level of neuronal communication and excitation. Voltra’s paper published in the journal Nature shows that the newly discovered glutamatergic astrocytes are concentrated in the hippocampus, a brain region associated with memory.
Liu Shiping told reporters that the hippocampus studied by Voltra this time is very critical for functions such as short-term and long-term memory formation and motor control. The hippocampus is also one of the most vulnerable areas to damage in the early stages of Alzheimer’s disease. Therefore, this new discovery has important implications for understanding neurodegenerative diseases such as Alzheimer’s disease.
Liu Shiping particularly emphasized that this study implies that the complexity of cell types in the brain is far beyond our previous understanding, and more research is needed to deeply understand this complexity.
Possible to change understanding of brain function (photoAC)
For example, the “Brain Atlas Project” is being carried out comprehensively to map the gene expression and spatial distribution characteristics of human brain cells, and conduct more in-depth research on cell types, including gene expression and functional studies. These studies will help reveal the complexity of the brain. Furthermore, these novel glial cells may exist in multiple species but may differ in their functions. Therefore, cross-species studies are important to gain a deeper understanding of the origin and evolution of these cells.
2023-10-13 09:50:17
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