Speaker
Description
Navigation is a complex goal-directed behaviour that requires the integration of sensation, reward, motion, and internal spatial representations to understand one’s position in the environment. Forms of spatial representations were identified in many brain regions beyond the hippocampal formation. However, these findings arose from a variety of experimental conditions, often not suited to isolate spatial from other navigational signals, such as visual landmarks.
Here we show that navigation recruits a distributed network of highly mixed-selective neurons tuned to combinations of running, sensation, reward, and position in an audiovisual virtual corridor. By decoupling position from external inputs and idiothetic processes, we found that all navigational signals contributed to activity of many of the 20.777 neurons we recorded across the mouse brain. Although the hippocampus showed a modest overrepresentation of spatial processes, like most regions it contained highly mixed-selective neurons.
Our study is the first to systematically demonstrate that spatial navigation engages brainwide, mixed representations of sensation, reward, motion, and position.
Lay Abstract
When we move through the world, our brains must juggle multiple streams of information: where we are, what we can see and hear, how fast we're moving, and whether we're heading somewhere rewarding. Scientists have long assumed this was handled primarily by a dedicated "navigation centre," particularly a region called the hippocampus.
We challenged that view by recording the activity of over 20,000 brain cells across the entire mouse brain while mice navigated a virtual audiovisual corridor. By carefully separating the different processes involved (movement, sensation, reward, and position) we could study how each one shapes brain activity.
We found that navigation is far more widespread than previously thought. Rather than relying on specialised regions, the brain uses a distributed network of brain cells that each respond to multiple signals at once. A single neuron might be sensitive to both speed and position in the corridor simultaneously. While the hippocampus had relatively more brain cells sensitive to position than other brain regions recorded, it was, like nearly every other region, dominated by these multi-signal cells.
Thus, rather than being confined to dedicated brain regions, navigational information is represented across the brain in a highly distributed fashion.
| Lay Title | Finding Your Way: How the Whole Brain Works Together to Navigate |
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| Role | Postdoctoral Researcher |