Objective
Updating behavior based on environmental feedback is essential for organisms to learn and develop optimal behavioral strategies. Norepinephrine (NE) release from the locus coeruleus (LC) has been recently shown to critically mediate reinforcement learning (RL), such that a high level of NE released after a reward prediction error (RPE) improves subsequent behavior. However, the mechanism by which transient LC-NE neuron activity (lasting 50-300 ms) influences behavior several seconds later remains unclear.
Building on experimental findings in the Outgoing Phase supervisors laboratory, we hypothesize that astrocytes play a previously unreported role in RL: they temporally amplify specific NE-RPE signals, facilitating the exploitation of neuronal sensory information when it is needed to optimize subsequent behavior. We will now probe the theoretical advantages of the novel NE-astrocyte RL mechanism by combining advanced computational analysis and modeling of rich neuronal and astrocytic cortical population recordings during RL.
We will investigate computationally and theoretically the role of NE and astrocytes in modulating neuronal population dynamics supporting post-reinforcement behavioral gain. We will use data sets available in the Outgoing Phase supervisors laboratory to address three main scientific questions: 1) How do NE-RPE signals affect the future encoding of task-relevant information in neuronal populations? 2) How do in vivo neuro-astrocytic interactions support cross-population information processing critical for RL? 3) What is the role of NE-astrocytic signaling in RL - how is it biophysically supported, and implemented in novel RL algorithms and recurrent astrocyte-neuron networks (RANNs)?
Altogether, I expect this proposal to be transformative in advancing our understanding of learning mechanisms in biological systems, and that they will potentially inform new algorithms for RL based not only on networks of neurons but also including astrocytes.
Keywords
Programme(s)
- HORIZON.1.2 - Marie Skłodowska-Curie Actions (MSCA) Main Programme
Funding Scheme
HORIZON-TMA-MSCA-PF-GF - HORIZON TMA MSCA Postdoctoral Fellowships - Global FellowshipsCoordinator
20251 Hamburg
Germany