In a significant advance in the field of neuroscience, researchers at the Institute of Photonic Sciences (ICFO) have developed an innovative system that uses photons instead of chemical neurotransmitters to control neuronal activity. This new method, detailed in the journal Nature Methods, could revolutionize the understanding and treatment of neurological disorders, as well as expand our cognitive and behavioral capabilities.
The human brain functions through synaptic transmission, a process by which billions of neurons send and receive electrical and chemical signals. Chemical neurotransmitters are released from one neuron and travel to others, generating a signal that can excite, inhibit, or modulate cellular activity. This delicate balance of signals is essential for the brain to process sensory information, make decisions, and execute behaviors.
Conventional methods for controlling neuronal activity include the use of drugs and electrical stimulation. However, a third option has been recently explored: the use of light. Manipulating neuronal activity using photons is possible thanks to the genetic modification of neurons to express light-sensitive proteins and ion channels. However, this approach presents technical challenges and limitations, as light can scatter in brain tissue and its administration requires invasive techniques.
The ICFO team, led by Professor Michael Krieg and with Montserrat Porta as the first author, has devised a system called PhAST, which uses luciferases (light-emitting enzymes) and photosensitive ion channels. This method was tested on the nematode Caenorhabditis elegans, a widely used model organism in biological studies. By genetically modifying the worms and altering their neurotransmitters to make them insensitive to mechanical stimuli, the researchers demonstrated that photons can reverse these sensory alterations and restore neuronal communication.
The technique also allows for the observation of calcium activity in sensory neurons, using a specific microscope assisted with machine learning. With this setup, the researchers were able to restore neuronal connections, suppress responses to painful stimuli, and change attraction to aversion behaviors in response to olfactory stimuli.
The results obtained indicate that photons can act as neurotransmitters, allowing for precise communication between neurons. This opens up a new avenue for controlling and monitoring neuronal activity, offering applications in both basic research and clinical practice. In the future, improving the engineering of bioluminescent enzymes and ion channels could lead to non-invasive and highly precise optical manipulation of neuronal function. This advancement promises to revolutionize our understanding of brain function and provide new tools for treating damaged neurons without the need for invasive surgeries.
Source: MiMub in Spanish
