November 22, 2024
Authors: J. Quinn Lee, Alexandra T. Keinath, Erica Cianfarano, Mark Brandon
Think back to the last time you took a walk in a park: as you walked the different paths, your hippocampus helped you create a mental map to find your way back later. The hippocampus is a small, curved structure in the brain that scientists have studied for decades. Dr. Mark Brandon and his research group, located at the Douglas Research Centre and affiliated with McGill, have been focused on improving our understanding of how the hippocampus works. Along with other neuroscientists, they believe this part of the brain is essential for helping us navigate our daily world, whether it’s remembering a route, recognizing a location, or even planning a new path through an area we don’t know well.
However, until now, experiments looking to evaluate different theories about how the hippocampus works have been limited and have not allowed for clear and unbiased comparisons between hippocampal activity and the predictions made by competing theories of the hippocampus. Namely, researchers didn’t have the means to explore how thousands of neurons in the hippocampus respond when animals move through varied environments and the tools to compare these neuronal responses to theories.
Brandon’s study, led by senior postdoctoral researcher Dr. Quinn Lee, employed a miniaturized microscope, small and light enough to be carried by mice, to analyze these neuronal responses. They observed how the neurons in the hippocampus activate when animals navigate different spaces, such as mazes or rooms of varying shapes. By doing this, they discovered that, even though each brain is unique, there are common patterns in how these neurons are activated when an animal navigates through new spaces.
What is particularly interesting is that this research provides important answers to some long-standing questions about the hippocampus. Using their approach, Brandon and his team showed that only a handful of the competing hippocampal theories were able to accurately replicate how real hippocampal neurons adapt to ever-changing environments.
In summary, this study does not just provide theoretical information; it offers a concrete framework for better understanding how our brain creates representations of space – and how we understand and remember the world around us. These discoveries could not only advance research on navigation and memory but also have important implications for better understanding certain memory-related conditions, such as Alzheimer’s disease.