Neuroscience, a study coordinated by the Sant'Anna School of Advanced Studies investigates the mechanisms for encoding contextual information in the brain
How is contextual information elaborated by the brain? A study coordinated by Eleonora Russo, a researcher at the BioRobotics Instituteof the Sant’Anna School of Advanced Studies (Pisa, Italy), investigates the mechanisms underlying the encoding of contextual information in the hippocampus, a region of the brain that is crucial for spatial orientation and the formation of new memories.
Published in Nature Communications and carried out in collaboration with the University of Bristol and the Central Institute of Mental Health in Mannheim, the study “constitutes a step forward in understanding how our brain integrates contextual information, allowing us to adopt different behaviours depending on the context and to form distinct memories for each episode” says Dr Russo.
The hippocampus, our internal GPS
There are physical places that over time have seen us perform different actions in different contexts. Take a square as an example: we may have been there at a concert or demonstration but also, at another time, to have a coffee with friends. In order to understand how the brain distinguishes between these events, Russo and colleagues studied the hippocampus, a region in the temporal lobe of the brain highly involved in the integration of multisensory information.
The hippocampus functions like a GPS, providing us with information about our position in space. In addition to encoding spatial information, the hippocampus also receives information from various sensory domains - such as sight, hearing, smell - which is integrated here to form complex, multifaceted memories. In this way, the hippocampus creates personalised maps of the environment, enriched by the various sensory and contextual elements associated with our experiences in each location.
Theta sequences, spatial and contextual information summarised in milliseconds
One way in which the hippocampus communicates with the rest of the brain is through theta sequences, packets of activity in which neurons fire in orderly and rapid succession. Theta sequences compress spatial and contextual information into a few milliseconds. It is precisely this temporal compression that is crucial for the consolidation of experiences, during sleep, into long-term memories.
The collaboration between Sant'Anna School, the University of Bristol and the Central Institute of Mental Health in Mannheim
The study led by Eleonora Russo sees the collaboration with Matt Jones, Professor in Neuroscience at the University of Bristol, and Daniel Durstewitz, Professor in Neuroscience at the Central Institute of Mental Health in Mannheim and the University of Heidelberg. The study combined new experimental data with mathematical models to show how hippocampal neurons could flexibly change the order of their activation within theta sequences depending on the contextual information they process.
"This observation not only helps us better understand how contextual information can be used to guide our behaviour, but suggests potential strategies used by our brain to store episodic memories" says Dr. Russo.
