Revolutionary Pulses of Light: A Breakthrough in Seizure Control Solutions

Researchers at UC San Francisco, UC Santa Cruz, and UC Berkeley are exploring a new treatment for epilepsy. They have used light pulses to stop seizure-like activity in brain neurons. This research utilizes brain tissue from epilepsy patients.

The goal is to develop a technique that could replace surgery, allowing for a less invasive treatment option for patients whose medication fails to control their symptoms. The method called optogenetics uses a harmless virus to introduce light-sensitive genes into targeted neurons in the brain. These neurons can then be activated or deactivated using light.

This is the first time optogenetics has been shown to control seizure activity in living human brain tissue, potentially paving the way for new treatments for various neurological conditions. Dr. Tomasz Nowakowski, a co-author of the study, emphasized the significance of this advancement for treating epilepsy.

To conduct their work, the team created an environment that mimics the conditions inside the skull, keeping the brain tissue alive for several weeks. Dr. John Andrews set the tissue on a nutrient medium similar to cerebrospinal fluid while Dr. David Schaffer selected the optimal virus for gene delivery.

They placed the tissue on small electrodes capable of detecting neuronal electrical discharges. Normally, neurons communicate with each other through a mix of signals, but during a seizure, this communication becomes synchronized and chaotic. The team aimed to use light pulses to inhibit these bursts by turning off neurons with light-sensitive proteins.

To minimize any disturbance to the tissue, Dr. Mircea Teodorescu developed a remote-control system. This system allowed the researchers to record the neurons’ activity and deliver light pulses without being physically present in the room with the brain tissue.

Optogenetics also allowed the researchers to identify specific neuron types essential for seizure initiation and the minimum light intensity needed to modify the electrical activity in live brain slices. Their findings revealed how neuron interactions can suppress seizures.

Dr. Edward Chang believes this approach could change epilepsy treatment by providing effective control over seizures without resorting to invasive surgery. This research opens new doors for epilepsy care and possibly other neurological disorders.

Source: University of California – San Francisco

Journal reference: Andrews, J. P., et al. (2024). Multimodal evaluation of network activity and optogenetic interventions in human hippocampal slices. Nature Neuroscience. doi.org/10.1038/s41593-024-01782-5