Currently, scientists are able to develop neurons and other brain cells from stem cells. However, it is difficult to transplant the neurons properly. With the new findings, the researchers are able to move past this hurdle.

“We showed for the first time that embryonic stem cells that we’ve programmed to become neurons can integrate into existing brain circuits and fire patterns of electrical activity that are critical for consciousness and neural network activity,” explained the study’s senior author Stuart A. Lipton, a clinical neurologist, in a prepared statement.

In the study, the team of investigators transplanted neurons from human stem cells into a rodent hippocampus, the brain’s informational processing center. Next, each of the transplanted neurons was activated with optogenetic stimulation. Otpogenetic stimulation is considered a new technique that mixes light and genetics together to specifically control the cellular behavior of animals or living tissues.