Ben Zarov

What if the brain's electrical connections are much smarter than we thought? Electrical synapses are specialized connections that allow brain cells to communicate directly through tiny channels called gap junctions. Unlike chemical synapses, which rely on neurotransmitters to carry messages between neurons, electrical synapses permit rapid communication through the direct flow of electrical current. Alberto Pereda and Adam Miller describe in a new review in Nature Reviews Neuroscience why we may need to rethink what an electrical synapse actually is, and how it works. Key points: - Electrical synapses are not simply passive channels connecting neurons. They are dynamic structures capable of changing the strength of communication between brain cells. - Gap junctions are supported by a complex network of proteins, including connexins, scaffolding proteins and regulatory molecules that control how electrical signals are transmitted. - Neurotransmitters such as dopamine, synaptic activity and molecular processes can modify electrical coupling, suggesting that electrical synapses may play a much more sophisticated role in brain plasticity and network function than previously appreciated. My take: This review resonates w/ me because it challenges a fundamental assumption about how the brain communicates. For decades, we have frequently thought about electrical synapses as relatively simple connections and chemical synapses as the more adaptable and sophisticated partners. That distinction may be misleading. Electrical synapses can change, adapt and interact w/ chemical signaling systems. As someone who spends much of my time thinking about Parkinson's disease, dopamine and deep brain stimulation (DBS), I find this particularly fascinating. We frequently focus on which brain circuits are firing abnormally and how stimulation can alter their activity. However, could we also be missing an important part of the story by not paying enough attention to how neurons are electrically connected and how those connections change? This is a basic neuroscience review, not evidence that manipulating electrical synapses will improve DBS outcomes, however it opens important questions for future research. Here are 5 points that resonated w/ me: 1- Electrical synapses are not fixed electrical wires. Their strength can change depending on brain activity and the molecular environment. 2- Dopamine may influence more than chemical signaling. It can also regulate electrical communication between neurons, a fascinating concept when thinking about Parkinson's disease. 3- The proteins surrounding gap junctions may be just as important as the channels themselves. The machinery supporting a connection can influence how that connection functions. 4- Electrical and chemical synapses do not operate in isolation. Their interactions may help explain how brain circuits adapt, synchronize and process information. 5- Could understanding electrical synapse plasticity eventually help us develop smarter neuromodulation approaches, including more personalized DBS? We do not yet know, however this is an exciting direction worth exploring. nature.com/articles/s41583-0…