In human brains, connected neurons strengthen their links when they activate at the same time. This is part of neural plasticity, the brain's ability to change and adapt. However, when scientists grow neurons in a dish, these cells don't behave the same way. They form random connections and fire in unison, not like real brain learning.
Researchers at Tohoku University have found a way to make lab-grown neurons act more like those in living brains. They have used a microfluidic device with microchannels that help neurons link up in patterns similar to those in animal nervous systems.
By adjusting the size of these microchannels, the scientists could control how the neurons connected. In experiments, they saw that networks with smaller microchannels had more complex patterns of activity. These patterns included groups of neurons, called neuronal ensembles, which are key to how the brain stores and recalls information. In real brains, these ensembles shift and change with new experiences, helping with learning and memory.
The team's findings showed that with the right setup, lab-grown neurons could form several different ensembles, not just one as seen in simpler setups. They also observed that repeated stimulation could change these ensembles, much like how experiences shape memory in the brain. This suggests these lab-grown networks can mimic some aspects of neural plasticity.
Better models for brain functions
This research, described in a paper published in Advanced Materials Technologies, opens new doors for studying how brains learn and remember without the complexities of using live animals. By making lab-grown neurons behave more naturally, scientists can better understand brain functions under controlled conditions. This could lead to better models for exploring specific brain functions, like memory formation and retrieval, in the future.
"Lab-grown neurons allow scientists to explore how learning and memory work in highly controlled conditions," says researcher Hideaki Yamamoto in a Tohoku University press release. "There is a demand for these neurons to be as close to the real thing as possible."