Neurons use biophotons to communicate without going through synapses.

It has been suggested that neurons can communicate using light (biophotons) rather than through synapses. They propose that neurons can generate biophotons, which originate in mitochondria, and that this light can be used for communication between neurons and for cell repair. They discuss that biophotons carry information about the state and activity of neurons, and that external light (e.g., infrared light) can facilitate the repair process. They suggest that the role of biophotons could have great potential for neuroscience and treatment. It is also hoped that biophotons may hold the key to solving the mystery of the human brain's instantaneous cognitive abilities, which cannot resolve the speed of synaptic connections, and, unlike AI, consumes almost no energy.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8643059/