MIT and Harvard University researchers develop new technique to control now neurons in the brain respond to light stimuli: 'You could imagine potential therapeutic applications'

Researchers at MIT and Harvard University have developed a new technique to manipulate neuron activity that could help better understand brain processes and disorders and help develop targeted therapies for neurological conditions.

According to a press release, Optogenetics is a technique used by scientists to manipulate neuron activity by engineering light-sensitive ion channels to explore the functions of specific neurons and how they form circuits. MIT and Harvard researchers have recently found a way to achieve longer-term changes in neuron activity by using light exposure to change the electrical capacitance of neurons’ membranes, altering their excitability. 

“This new tool is designed to tune neuron excitability up and down in a light-controllable and long-term manner, which will enable scientists to directly establish the causality between the excitability of various neuron types and animal behaviors,” says Xiao Wang, Assistant Professor of Chemistry at MIT, and a member of the Broad Institute of MIT and Harvard, according to the press release. “Future application of our approach in disease models will tell whether fine-tuning neuron excitability could help reset abnormal brain circuits to normal.” 

In their research, the team focused on altering the capacitance of the cell membrane, a key determinant of its ability to conduct electricity, to generate longer-lasting changes in neuron excitability.

Altering capacitance has been linked to a range of brain processes, including learning and aging, and has also been observed in some brain disorders. The researchers believe the technique could help shed light on how changes in neuron excitability affect disorders such as multiple sclerosis and Alzheimer’s disease. Researchers are now working on adapting this technique to study the brain tissues of animals. 

“If we have a certain neuron population that we know has higher or lower excitability in a specific disease, then we can potentially modulate that population by transducing mice with one of these photosensitizing proteins that’s only expressed in that neuron type, and then see if that has the desired effect on behavior,” Wenbo Wang says, according to the press release. “In the near future, we’re using it more as a model to investigate those diseases, but you could imagine potential therapeutic applications.”