Researchers have succeeded in growing active brain networks

Researchers report their success in developing functional neuron networks derived from organoids of brain cells

[Translation by Dr. Nachmani Moshe]
Brain cell organoids are XNUMXD aggregates of artificially grown tissue cultures and are similar in their spatial structure to a human brain. Now, researchers from Japan report in the scientific journal Stem Cell Reports on the development of functional neuron networks derived from these organoids. Although the organoids do not perform "thinking", the researchers' new tool - which allows to locate neural activity with the help of these organoids - could provide a method for understanding the functioning of the human brain.

"In view of the fact that they are able to mimic brain development, organoids of brain cells may be used as a model for the human brain for the study of complex developmental and neurological diseases," says lead researcher Jun Takahashi from Kyoto University. However, these studies are a challenge, since existing organoids of the brain lack necessary support structures, such as blood vessels and tissues, he adds and explains. Since researchers also have a limited ability to assess the neuronal activity of the organoids, it has also been difficult to comprehensively assess the role of neuronal networks.

"As part of our research, we were able to create a new analytical tool that allows for an in-depth assessment of dynamic changes in the network activity of about ten thousand brain cells," explains one of the researchers. "The exciting thing about this research lies in the fact that we were able to detect dynamic changes in the activity of calcium ions and predict cell activities." To prepare the organoids, the researchers created pluripotent stem cells that have the potential to differentiate into a variety of body tissues. In the next step, they placed the cells in a dish with a culture medium that mimics the environment required for the development of brain cells. Using the organoids, the research team was able to observe coordinated and uncoordinated activity in networks and within the junctions between individual neurons. The coordinated neuronal activity can be the basis of many brain functions, including memory.

"We believe that our research provides the possibility for a broad evaluation of neuronal activity derived from human cells", claims one of the researchers. The method could help researchers understand processes in which information is encoded in the brain through the activity of a defined population of cells, as well as the basic mechanisms responsible for the development of psychiatric diseases, the researcher explains. Although brain organoids provide a means of studying the human brain, ethical concerns have been raised in the past regarding the neural role of brain organoids.

"Since organoids of the brain mimic the development process, there is a fear that in the future they will also have mental activities, such as consciousness," explains the researcher. "Some people will remember the famous "brain in a jar" thought experiment conducted by Hilary Putnam in which a brain immersed in a life-preserving liquid and connected to a computer may grow a consciousness similar to that of humans." At the same time, the researchers believe that brain organoids will not develop consciousness since they do not receive data from the environment that surrounds them. "Awareness requires a subjective experience, and organoids of brain cells without sensory tissues will not receive sensory input and generate a motor output," explains the lead researcher. "However, if organoids of brain cells with an input and output system develop awareness that requires the existence of moral consideration, the basic and applied research of these organoids will become a significant ethical challenge."

In the future, applied research in organoids will likely test three main areas - drug discovery, modeling of neuropsychiatric diseases and regenerative medicine, the researcher claims. "Organoids of brain cells could generate considerable progress for pharmaceutical companies by converting traditional animal models and could also be used to model neurological diseases that cannot be treated today," says the researcher. "Using our method, it will be possible to diagnose patterns of cellular activity within the framework of brain functions in order to further examine these areas."

The article describing the study

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