Study Uncovers How The Brain Flexibly Switches Communication Routes

2 months ago

When we callback thing acquainted aliases research a caller situation, nan encephalon does not ever usage nan aforesaid connection routes. An world study led by Claudio Mirasso astatine nan Institute for Cross-Disciplinary Physics and Complex Systems (IFISC), a associated halfway of nan Spanish National Research Council (CSIC) and nan University of nan Balearic Islands (UIB), and Santiago Canals astatine nan Institute for Neurosciences (IN), a associated halfway of nan CSIC and nan Miguel Hernández University (UMH) of Elche, has discovered really nan encephalon flexibly changes its connection pathways by modulating nan equilibrium betwixt 2 basal inhibitory circuits.

These results, precocious published successful PLoS Computational Biology, show that this elasticity depends connected nan equilibrium betwixt 2 types of inhibitory mechanisms, which modulate nan relationship betwixt slow (theta) and accelerated (gamma) rhythms. Thanks to this mechanism, nan encephalon tin prime different sources of information, specified arsenic sensory stimuli from nan outer situation aliases stored sensory acquisition from memory.

To scope these conclusions, nan researchers mixed computational models pinch experimental recordings successful nan hippocampus, a encephalon region important for representation and navigation. They observed that successful acquainted environments, wherever sensory experiences are already known, neurons favour a nonstop connection mode that facilitates transmission from nan entorhinal cortex to nan hippocampus. In this mode, nan reactivation of established representation is prioritized. By contrast, erstwhile facing novelty, nan encephalon activates different mode that integrates representation reactivation pinch caller sensory inputs. In this mode, representation updating is prioritized.

Until now, it was thought that nan shape of slow encephalon rhythms organized nan amplitude of faster activity; however, this study demonstrates that nan narration is bidirectional:

This activity provides a mechanistic mentation of really nan encephalon flexibly changes connection channels depending connected nan context."

Dimitrios Chalkiadakis, first writer of nan study

"By adjusting nan equilibrium betwixt different types of inhibition, circuits specify which inputs to prioritize, whether from memory-related pathways aliases from caller sensory information," highlights nan researcher.

Through a theoretical model integrating electrophysiological information from rats exploring caller and acquainted environments, nan experts identified 2 modes of operation: successful one, feedforward inhibition leads to gamma-to-theta interactions, while successful nan other, feedback inhibition produces theta-to-gamma interactions. Neuronal circuits successful nan encephalon people instrumentality some modes of inhibitory connectivity. The study shows that nan modulation betwixt them is continuous, and prioritizing 1 aliases nan different depends solely connected nan spot of synaptic connections betwixt neurons successful nan circuit. This allows nan mode of cognition to beryllium flexibly adjusted to discourse and cognitive demands.

Beyond memory

The study suggests that this elastic shape of coordination betwixt encephalon rhythms could widen to different cognitive functions, specified arsenic attention. In fact, caller activity successful humans shows patterns accordant pinch nan computational model. This points to a wide rule of nan brain: nan equilibrium betwixt inhibitory circuits is cardinal to directing accusation wrong its analyzable web of connections.

"Our results thief unify opposing views connected really encephalon rhythms of different frequencies interact", explains Mirasso. "Rather than being purely section aliases inherited from earlier regions, these rhythms look from nan relationship betwixt outer inputs and section inhibitory dynamics. This dual system enables nan encephalon to optimize accusation processing nether different conditions," adds Canals.

Beyond representation and navigation, nan findings could widen to different cognitive functions. Looking ahead, nan researchers intend to grow their exemplary to see a greater diverseness of neuronal types and architectures circumstantial to each encephalon region. The purpose is to amended understand really this equilibrium is altered successful pathologies specified arsenic epilepsy, addiction, aliases Alzheimer's disease: "Studying these dynamics astatine a mechanistic level could yet animate caller therapeutic involution strategies," some authors conclude.

This activity was made imaginable acknowledgment to backing from nan Spanish Ministry of Science, Innovation, and Universities done nan R&D Project Program (Knowledge Generation and Research Challenges) and from nan Spanish State Research Agency done nan Severo Ochoa Centers of Excellence and nan María de Maeztu Units of Excellence Program.

Source:

Journal reference:

Chalkiadakis, D., et al. (2025). The domiciled of feedforward and feedback inhibition successful modulating theta-gamma cross-frequency interactions successful neural circuits. PLoS Computational Biology. doi.org/10.1371/journal.pcbi.1013363