# Role of multi-regional neuronal reactivations in reward-based memories > **NIH NIH K99** · JOHNS HOPKINS UNIVERSITY · 2024 · $121,608 ## Abstract PROJECT SUMMARY The goal of this project is to provide the building blocks for an independent research program focused on the neural basis of reward-based memory across distributed brain networks. Humans and other animals experience events in the moments they occur while the brain has evolved powerful neural processes to re-activate the neurons encoding these events in the ‘time in-between’. Reactivation of task-relevant neuronal ensembles occur during both wake and sleep states, and enable the binding and compression of neuronal representations in a temporal window compatible with neuronal plasticity. The role of awake and sleep reactivations in supporting episodic, hippocampus-dependent memories is well established. However, reactivation have been reported to also occur beyond the hippocampus, in both cortical and subcortical structures, and in both hippocampal- dependent and -independent tasks. This leads to the exciting possibility that reactivations may be a fundamental mechanism underlying memory formation and consolidation, and that they occur brain-wide, distributed among regions encoding different modalities and variables. However, their role in cue-driven, goal-directed sensorimotor tasks remain largely unexplored and evidence of multiregional reactivations is weak, in part because of technical difficulty to investigate neuronal population activity across multiple simultaneously recorded brain circuits. This proposal aims at testing the role of multi-region neuronal reactivations during wake and sleep in forming and consolidating associative networks to support reward-based learning. In the K99 phase, Dr. Drieu will focus on the role of multi-regional reactivation in cue-guided, goal-directed learning. She will test the hypothesis that the simultaneous reactivation of stimulus-, action-, and reward-selective neurons across brain regions during the waking state forms associative networks (Aim 1) subsequently reactivated during sleep for consolidation (Aim 2). In the R00 phase, Dr. Drieu will address whether transient synchronous activity spanning multiple brain areas in different brain states participate in the transition from cue-driven, allocentric memories to egocentric memories (Aim 3). To achieve these goals, Dr. Drieu will perform high-density, multi-site neuronal recordings using Neuropixels 2.0 combined with advanced closed-loop optogenetic methods in freely moving rats. The technical and scientific skills that Dr. Drieu will develop during the training period of this project will not only be crucial for the accomplishment of her immediate scientific goals, they will also become the pillars for the research she will develop in her own independent laboratory in the field of reward-based learning and memory. This training will be complemented by intense career developmental activities and mentorship that will prepare her for the practical aspects of laboratory management, teaching and fund raising. Overall, Dr. Drieu’s future resea... ## Key facts - **NIH application ID:** 10875435 - **Project number:** 5K99DA059024-02 - **Recipient organization:** JOHNS HOPKINS UNIVERSITY - **Principal Investigator:** Celine Drieu - **Activity code:** K99 (R01, R21, SBIR, etc.) - **Funding institute:** NIH - **Fiscal year:** 2024 - **Award amount:** $121,608 - **Award type:** 5 - **Project period:** 2023-07-01 → 2025-06-30 ## Primary source NIH RePORTER: https://reporter.nih.gov/project-details/10875435 ## Citation > US National Institutes of Health, RePORTER application 10875435, Role of multi-regional neuronal reactivations in reward-based memories (5K99DA059024-02). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10875435. Licensed CC0. --- *[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*