Our brains have incredible powers of information processing, allowing us to understand and interact with the world around us, and to learn and store this information for the future. However the brain is also an incredibly complex organ, formed of billions of neurons, interconnected by synapses, therefore understanding the brain’s processing is an incredibly challenging task. As are we currently unable to explain the brain’s actions, we are also unable to understand how things go wrong in neurological disorders, therefore extensive research into this ‘last frontier’ in human physiology is critically needed. The incredible functions of the brain arise from continuous electrical activity passing through specific cells in the tangle of neural circuitry. Understanding the brain’s mechanisms of information processing therefore requires measurement and characterization of how the connections between neurons are arranged, and the properties of their communication.
Here, we aim to determine the arrangement and properties of connections between neurons in the CA3 area of the hippocampus, a critical brain area for memory storage. Neurons have diverse cell types, meaning that the properties of cells and networks are highly heterogeneous, adding complexity to both the brain’s processing and our investigation. By recording the properties of multiple individual neurons at high resolution simultaneously, we determine ‘wiring rules’ for this brain area at the level of single cells. We aimed to use this approach to understand the basic processing units of the hippocampus, so we can begin to understand how activity flows through this brain area, and how this information flow can give rise to learning and memory.
