How do neurons in the brain communicate? The answer is ‘very quickly’. Your brain forms a network of 100 billion excitable cells all passing electrical currents between each other to produce your experience of the world around you. But how can simple electrical currents give rise to the human experience of creativity, memory, imagination? Before we can begin to address these big questions, we need to start with the small ones: how do neurons in the brain communicate?

When we look at the nervous system, we see spikes in electrical activity which seem to pass from neuron-to-neuron. Most neurons aren’t physically connected to each other though, so how does the signal jump between them? The communication happens at specialised connections called synapses. When a neuron spikes, several tiny packets of chemicals are released at a synapse towards another neuron which detects them and responds, potentially with a spike of its own. In this way signals are passed from neuron to neuron, across the entire nervous system.

The combination of electrical and chemical processes allows for flexible communication at synapses, but there are certain patterns of communication which indicate brain dysfunctions such as in epilepsy or migraine. To understand what causes these patterns, healthy or otherwise, we need to look at the protein structures which enable them.

The trouble is, proteins are small, and the interactions between them are extremely fast, so much so that they cannot be resolved in cells using current experimental techniques. This is why we have developed a mathematical model capable of simulating synaptic release under a variety of different protein structures. Our efficient algorithm takes only minutes to simulate 1000’s of chemical packets in a computation that would take weeks using state-of-the-art atomic physics models. With this, we have provided the first mechanistic description of how proteins can both trigger a signal within milliseconds, but also sustain that signal for several thousand times as long.

These proteins control the speed and precision of communication across the whole brain. Understanding them will affect not only how we investigate higher brain function, but will have applications in neurotechnology, and artificial intelligence. The immediate impact however will be for the treatment of neurological disorders associated with synaptic dysfunction. These include epilepsy, schizophrenia, and Alzheimer’s disease among others, and with a clear understanding of protein function we will have the basis for novel, targeted treatments.

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