Our ability to interpret the world and select appropriate actions depends on the integration of sensory information with prior knowledge. In mammals, sensory signals are first processed in specialized brain areas, but only their combination with past experience and contextual cues allows flexible, adaptive behavior. This integration requires the propagation of information from sensory regions to higher association areas, where sensory inputs are put into context and memories are formed. In particular, the entorhinal-hippocampal network plays a key role in integrating information and supporting memory formation. Recent studies have shown that learning can alter activity in sensory areas, but it remains unclear whether these changes occur independently or reflect modified top-down input from associative regions.
Despite the modular organization of the brain, the study of individual areas in isolation is inherently limited. Local processing is shaped by abundant long-range connections, making it essential to understand how information flows between brain regions. The overarching aim of the project olfACTION is to uncover the principles that enable flexibility in the coordinated processing and propagation of sensory information across brain networks. We focus on olfactory processing in mice, from the early sensory areas of the olfactory bulb and piriform cortex to the higher association regions of the lateral entorhinal cortex and hippocampus. Olfaction provides unique advantages for this research: the pathway from sensory to association areas is short and the respiratory cycle offers a discrete temporal frame for information sampling.
The central hypothesis of the project is that the timing and synchrony of neuronal activity determine how information is transmitted between brain areas, and that these parameters are modulated by learning and context via feedback from association regions. To test this, we combine simultaneous electrophysiological recordings across olfactory and associative areas with pathway-specific optogenetic manipulations, odor-guided behavior, and anatomical tracing. State-of-the-art analytical tools will be applied to quantify neuronal interactions and information propagation at the population level.
Using these methods, the project will address fundamental questions about the brain: how is sensory information flexibly routed across brain areas? How does learning modify the timing and coordination of activity to influence downstream processing and behavior? And how does the brain adaptively reconfigure these pathways in response to changing contexts?
The project is highly interdisciplinary, integrating systems neuroscience, cellular and network-level investigations, behavioral analysis, and computational approaches. Its timeliness lies in the combination of cutting-edge techniques: multi-site electrophysiological recordings in behaving mice, pathway-specific optogenetics, and advanced analytical tools for population dynamics and directed interactions. By advancing our understanding of the mechanisms controlling information propagation, this research will provide key insights into how the brain integrates sensory input with prior knowledge and context to support flexible behavior. Ultimately, it lays the groundwork for understanding how disruptions in these processes contribute to cognitive disorders and may inform future strategies for intervention.
