This advancement in bioengineering has discovered a method to make laboratory-grown neurons behave similarly to those found in actual brains.
The phrase “Neurons that fire together, wire together” captures the concept of neural plasticity in human brains, yet neurons cultivated in a lab seem to disregard these principles. Neurons grown in vitro create random, unmeaningful connections that work simultaneously. Consequently, they do not accurately mimic the learning processes of a real brain, which limits the insights we can gain from them.
But what if we could engineer in-vitro neurons to act more like their natural counterparts?
A team of researchers at Tohoku University has utilized microfluidic devices to reconstruct biological neuronal networks that exhibit connectivity akin to that seen in animal nervous systems. Their findings indicate that these networks demonstrate intricate activity patterns that can be “reconfigured” through repeated stimulation. This significant discovery equips scientists with new tools to investigate learning and memory.
The results were published online in Advanced Materials Technologies on November 23, 2024.
In specific regions of the brain, information is organized and stored in “neuronal ensembles,” which are groups of neurons that activate together. These ensembles change in response to environmental signals, forming the neural foundation for our learning and memory processes. However, exploring these phenomena in animal models poses challenges due to their intricate structure.
“The necessity of cultivating neurons in the lab stems from the simplicity of these systems,” states Hideaki Yamamoto from Tohoku University. “Lab-grown neurons enable researchers to investigate learning and memory in a highly controlled environment. It is essential for these neurons to closely resemble real neurons.”
The research team developed a unique model using a microfluidic device—a small chip featuring minuscule 3D structures. This device facilitated the connection and formation of networks among neurons that closely mimic those found in the nervous system of animals. By adjusting the size and shape of the tiny channels (known as microchannels) connecting the neurons, the researchers could control the level of interaction between them.
The researchers found that networks utilizing smaller microchannels could sustain varied neuronal ensembles. For instance, in-vitro neurons grown on traditional devices typically displayed just a single ensemble, while those cultivated with smaller microchannels demonstrated as many as six ensembles. Furthermore, they observed that repeated stimulation could modify these ensembles, indicating a process akin to neural plasticity, as if the neurons were being reorganized.
This microfluidic technology combined with in-vitro neurons could potentially lead to the development of more sophisticated models that replicate specific brain functions, such as the processes of memory formation and recall.
