Understanding the Hippocampus Visually

I have always enjoyed looking at images that display biological systems in terms of their functional components. But oftentimes, existing diagrams show too much detail, too little detail, the wrong types of detail, or confusing captions/explanations. This seems especially common in neuroscience. Inspired by this challenge, I put together the image below to explain the fundamentals of hippocampal circuitry in a clean, unified manner.