— Irina Vasilievna stands as the first Russian researcher to grow brain tissue in a controlled environment and demonstrate that it can generate electrical signals. It has been 15 years since that breakthrough. Today, tens of thousands of Petri dishes fill the lab, where various brain cells are cultivated. The question remains: why grow them at all?
“A brain is a tissue that operates according to measurable parameters we can grasp, yet it also embodies the subjectivity of consciousness. Through it, we communicate with the world and gain insight into its workings. Does lab-grown brain tissue possess consciousness? This query surfaced in 1970, when scientists learned to culture neuronal networks on electrical sensors capable of recording potentials from those cultures. In short, a brain in a test tube can ‘think’ by transmitting intricate electrical signals.”
In 2008, the lead researcher’s bioengineering team began pursuing this line of inquiry. They achieved within five years what other teams worldwide spent decades pursuing, thanks to rapid access to progressing technologies. They laid down a fabric on which multielectrode arrays, produced by various global manufacturers, began to host growing neural networks.
– The laboratory reportedly housed a persistent neural tissue nicknamed “Alexander Gennadievich.”
Yes, it existed for nine months.
– That duration seems long, right?
– On balance, yes. In most labs that study neural networks in culture, neurons remain viable on chips for about 2–3 months. The limiting factor is nutrition rather than the brain’s nature.
– How long can neurons survive with optimal nourishment?
– In theory, human brain cells could live for a thousand years with the right supportive technologies for nutrition and oxygen supply, though nature seldom allows it. The work centers on mouse cells, which have a shorter natural lifespan. In culture, these neurons can persist for up to two years in some studies.
– And why did the “Alexander Gennadievich” tissue fail?
– The team created a tissue containing both neurons and glial cells, the supportive units of brain tissue. Glial cells continuously divide, and controlling their growth proved difficult. Their expansion created barriers to recording neuron signals with electrodes, so it could not be confirmed that the tissue was functioning. Additionally, the growth of glia caused the tissue to detach from its substrate, rendering it unable to stand on the electrodes. Consequently, the experiment was halted.
– What exactly is recorded when the cultured tissue emits an electrical signal? Is that a thought?
– Several graduate students in the lab have defended the methodology used to interpret these signals. The data show that tens of thousands of neurons in a compact tissue can produce a distinct, complex electrical pattern on a chip. They can generate a signal unique to a given culture, confirming its activity.
When researchers compare the brain’s response to the environment with microelectrodes implanted in a human or a mouse, they observe similarly intricate, spontaneous or stimulus-driven electrical patterns. From an external view, this complex activity may resemble mere noise, yet the tissue in vitro can reveal recognizable activity through recorded patterns.
The question is whether the tissue can articulate information it processes in a meaningful way, not just random activity.
– How was it demonstrated that the tissues process information and produce something meaningful?
– Two brain tissues were connected to form a unidirectional pathway. The second culture absorbed more complex information and then produced its own signal after processing that information. This suggests information transfer beyond a simple data stream.
– So, is it accurate to say the tissue is processing information?
– Information is a set of sign phenomena that may change or remain constant. The mathematics can distinguish between chance and purposeful signal processing. The aim for researchers is to understand how the brain processes information, identify the underlying algorithms, and translate them into neuromorphic intelligence. This approach could lead to faster, brain-inspired computing.
– Could it ever reveal exactly what a neuron is thinking in a test tube?
– It doesn’t sound fantastical to some researchers, but it remains a distant goal.
How might a lab-grown brain be used beyond observation?
– Could it serve as a control system for a machine? In one experiment, a culture that reliably produced signals was programmed to steer a device. A radio-controlled car was guided by the culture’s patterns: one signal pattern directed the vehicle left, another right. The control brain stayed in the incubator, while the signal traveled via Wi-Fi to the machine. When an obstacle appeared, a feedback signal was sent back to the culture. The result looked almost comical in how the setup operated.
– Are there instances where the adult brain, rather than a culture, directs the machine’s movement?
– No such studies exist, either in science or fiction. At present, communication hinges on electrical signals rather than spoken language, and thoughts are not arranged as words but as action potentials. Eyes and ears are not present in this isolated tissue to interpret language; environmental cues still need to be converted into electrical signals that the brain can analyze.
The laboratory explores how to create a warm, oxygen-rich environment for cells, sometimes adjusting oxygen levels, lighting, or adding compounds that affect synaptic transmission. These interventions alter the electrical activity patterns, enabling researchers to map response rates, locations, and timing. From this, formulas can be derived to model how cells perceive information, forming the basis for artificial intelligence applications.
– What projects are ongoing, and what plans lie ahead for the lab?
– The research program runs in two streams. The first focuses on pure biology, modeling metabolic changes at the brain level in vitro to study disease mechanisms and potential treatments. It is a broad, ongoing effort with many researchers involved. The second stream centers on bioengineering and neuromorphic intelligence, aiming to merge electronic components with living tissue to create prostheses for medical use. A key goal is safe, efficient, long-term signal transmission between nerves and devices.
– Is it possible to connect more axons to electrodes?
– Today, 20 to 40 axons can be linked, but many more cells are involved in information processing. Increasing the number of connected axons will improve the precision of bionic prostheses. The task is to identify materials with the right conductivity to carry signals across micrometer-scale gaps rather than centimeters, as currently done.
– Is an adapter necessary?
– Yes. Materials scientists are actively developing new interfaces so future prostheses can transmit signals from a million axons instead of the few dozen possible today.