How does the brain find the way: investigating the neural circuits underlining the sense of direction

A fundamental ability of people and terrestrial animals is their capacity to navigate successfully in familiar environments without getting lost. To do this, people often orient themselves using visual landmarks such as conspicuous buildings in a familiar city (e.g., the castle in Edinburgh, or the Eiffel Tower in Paris). They can also use their own movements (e.g., turns they make, and distances travelled) to keep track of where they are relative to a starting point or to the last landmark.

How, in the brain, are these different types of information integrated to guide spatial navigation? This project will address this question by using cutting edge neurophysiological techniques in rodents performing spatial navigation tasks.

In the mammalian brain there are neurons that fire when an animal faces a specific direction. These are termed head-direction cells, and they are thought to provide the basis for a sense of direction. Recent evidence indicates that there are two types of direction representations in the brain: one that is driven primarily by self-motion cues, and a second that is driven primarily by external visual landmarks.1 However, the circuitry supporting these different types of direction representation, and how they are integrated to guide spatial navigation is not fully understood.

This project will examine how self-motion cues and visual landmark information are represented at different stages in the head direction circuit in both juvenile and adult rats, and how they are integrated to guide spatial navigation. This is an important issue in the field, as understanding the neural basis of navigation in healthy juvenile and adult subjects will provide a basis for understanding how and why spatial navigation is delayed or disrupted or in many neurodevelopmental conditions, and how it may be impacted during ageing and in neurodegenerative disorders.

The student conducting this work will gain expertise in rodent stereotaxic surgery, in vivo high-density electrophysiological recording and analysis of neuronal activity (single neurons, ensembles, local field potentials), and behavioural assessment of spatial cognition. All rodent work will be conducted at the University of Edinburgh in well-equipped laboratories for in vivo neuronal recording and behavioural assessment.

The student on this project will have the opportunity to present their work at national and international neuroscience meetings.