Computer model decoding the brain’s diversity
A computer model developed with support from the EU-funded NEMESIS, EBRAINS 2.0(opens in new window), VIRTUAL BRAIN TWIN(opens in new window) and HBP SGA3(opens in new window) projects is providing valuable insight into how the human brain works. As described in the study(opens in new window) published in the journal ‘Proceedings of the National Academy of Sciences’, the model shows that regional differences in the brain’s receptors help shape neural activity across the whole brain.
Bridging molecular details and global brain states
The brain is naturally diverse, with differences in its chemistry and structure ranging from the tiniest molecules to large anatomical regions. However, scientists have not fully understood how this diversity affects the brain’s overall electrical activity, and most large-scale brain models simplify things by treating every cortical region as if it worked the same way. “One of the central challenges in neuroscience is understanding how processes occurring at the molecular level influence the behaviour of the brain as a whole,” comments study first author Leonardo Dalla Porta of NEMESIS and HBP SGA3 project partner August Pi i Sunyer Biomedical Research Institute (IDIBAPS), Spain, in a ‘EurekAlert!’ news release(opens in new window). “Our study provides a concrete example of how we can begin connecting these very different scales within the same computational framework.” In this study, researchers developed a detailed computer model of the cortex that can simulate different brain states, from being awake to being asleep. Their model used real human data on how brain regions are physically connected and where specific receptors – muscarinic acetylcholine receptors – are located, based on both genetic data and brain imaging scans. The receptor maps were used to adjust how easily different brain regions become active. The team discovered that adjusting activity levels based on the natural layout of these receptors significantly changed how the whole brain network behaved. It improved synchronisation between regions and made information flow more efficiently. This suggests that the brain’s natural diversity helps different brain regions synchronise and share information more effectively, allowing the brain to switch flexibly between different states.
Unlocking the secrets of mixed brain states
Interestingly, the brain’s natural diversity also explains the coexistence of localised sleep-like activity within otherwise awake-like states. The team explored a complex situation where small brain areas showed sleep-like slow waves while the rest of the brain acted as if it were awake. They showed that this mix of states arises naturally from the combination of how much individual regions adapt to activity and how they are physically connected. Overall, the study supported by NEMESIS (NEurological MEchanismS of Injury, and Sleep-like cellular dynamics), EBRAINS 2.0 (EBRAINS 2.0: A Research Infrastructure to Advance Neuroscience and Brain Health), VIRTUAL BRAIN TWIN (Virtual Brain Twin for personalised treatment of Psychiatric Disorders) and HBP SGA3 (Human Brain Project Specific Grant Agreement 3) highlights that the brain’s molecular and structural diversity is essential for shaping its large-scale activity. This finding offers new ways to connect small-scale biological details to big-picture brain function, paving the way for more accurate simulations of neurological disorders and personalised treatments. For more information, please see: NEMESIS project EBRAINS 2.0 project web page(opens in new window) VIRTUAL BRAIN TWIN project website(opens in new window) HBP SGA3 project website(opens in new window)
