Venue: Centre Broca Nouvelle-Aquitaine
Matthew Larkum
Humboldt University, Berlin
https://www.projekte.hu-berlin.de/en/larkum/people/matthew-larkum-en
Invited by Richard Naud and Naoya Takahashi (IINS)
Title
New insights into decision-making and the principles of cortical operation
Abstract
The process of decision-making involves interactions between the frontal cortex and various cortical and subcortical regions. My laboratory has long focused on a theory of cortical function that centers on the active properties of dendrites in layer-spanning pyramidal neurons. According to this framework, categorically distinct types of information are processed in physically separated compartments within the same neuron and then combined through a nonlinear integrative mechanism. If this is a general principle of cortical operation, it should apply broadly across cortical areas, given their shared architecture. From this view, what distinguishes one cortical area from another is primarily the type of information delivered to specific layers. Having previously concentrated on sensory cortex, we have recently turned our attention to the frontal cortex, where this principle raises new questions. Here, I present findings from several studies examining how this framework applies to decision-making in the frontal cortex. In one study, we show that re-learning complex rules depends on active dendritic integration in layer 5 pyramidal neurons; blocking tuft activity impairs adaptation without affecting simple learned behavior. In a second, we find that slow, deliberate decisions correlate with structured sequences in layer 2/3 neurons of medial frontal cortex, while fast, impulsive choices disrupt this pattern. Together, these results give new insights into how pyramidal neurons at the top of the cortical hierarchy are used and can interact with pyramidal neurons elsewhere in the hierarchy.
Key publications
Maristany De Las Casas E, Killmann K, Drueke M, Muenster L, Ebner C, Sachdev R, Jaeger D, Larkum ME (2025) Tuft dendrites in frontal motor cortex enable flexible learning. Available at: http://biorxiv.org/lookup/doi/10.1101/2025.03.13.642781.
Nashaat M, Oraby H, Krasniqi F, Goh-Sauerbier ST, Bosc M, Koerner S, Karayel S, Kepecs A, Larkum ME (2024) The neural mechanisms of fast versus slow decision-making. Available at: http://biorxiv.org/lookup/doi/10.1101/2024.08.22.608577.
Takahashi N, Ebner C, Sigl-Glöckner J, Moberg S, Nierwetberg S, Larkum ME (2020) Active dendritic currents gate descending cortical outputs in perception. Nat Neurosci 23:1277–1285.
Takahashi N, Oertner TG, Hegemann P, Larkum ME (2016) Active cortical dendrites modulate perception. Science 354:1587–1590.
Zolnik TA, Bronec A, Ross A, Staab M, Sachdev RNS, Molnár Z, Eickholt BJ, Larkum ME (2024) Layer 6b controls brain state via apical dendrites and the higher-order thalamocortical system. Neuron 112: 805-820.