Electrical activity in the brain has been tracked by researchers at the University of Edinburgh to locate the section of the brain involved in maintaining spatial awareness.
This research furthers the understanding of how we perceive things visually (e.g. knowing our way around a familiar room with our eyes shut), understand and connect concepts (e.g. mathematics) and arrange information logically (e.g. in a presentation).
Dr Matthew Nolan, from the University’s Centre for Integrative Physiology, told The Student that one of the surprising results of the study was discovering that active (or excitatory) cells within the area of study are not directly connected to each other, as expected. Instead, these active cells “talk” to each other only through inhibitory cells, previously thought to suppress activity in the brain. This means that activating one excitatory cell will supress activity of other excitatory cells elsewhere in the communication circuit.
“To understand how this is used to work out where you are, imagine the network of excitatory cells is organised in a sheet. We sometimes think of the small group of active neurons as a bump in the sheet. When an animal moves, we imagine the bump moves around the sheet.
“In this way the identity of the active neurons, or members of the bump, can represent the location of the animal.
“Our results provide an explanation for how, at a cellular level, this bump mechanism works. This cellular explanation is new and was not previously anticipated.”
This research will be primarily useful for research into conditions affected by spatial awareness and the brain’s electrical rhythms, such as schizophrenia and Alzheimer’s disease.
Patients suffering from schizophrenia struggle to link separate aspects of events into an understandable and recognisable whole in their memory. Nolan believes that “only by understanding the cellular mechanisms by which neural circuits carry out computations that we can then begin to understand what goes wrong in disorders such as schizophrenia.”
Alzheimer’s disease is a result of neurodegeneration, where there is a progressive loss of structure or function of cells in the brain. The area of the brain studied by Nolan and his team is the first area in which loss of cells is observed during the development of Alzheimers, so this research about how these cells communicate with each other, is hoped to further the understanding of this disease.
This research could also be used in non-medical applications, such as inspiring navigation systems within robots, such as the Mars rovers and submarines.
Originally published in the Student, January 2013.