Abstract

Neuronal firing in the hippocampus has long been associated with diverse variables such as spatial location, time, sensory cues, rewards and motor actions. However, it has remained unclear whether these correlations reflect multiple distinct functions of hippocampal circuits or a more unified computational principle. In this work, researchers developed a behavioral paradigm in mice where spatial, auditory and reward cues were independently manipulated to vary their relevance. High‑density electrophysiological recordings across hippocampal ensembles revealed tuning to each modality. Crucially, by comparing animals’ movement trajectories and action sequences, the authors show that hippocampal spiking is more strongly aligned with internally generated action plans than with external sensory variables per se. Furthermore, this action‑aligned activity was modulated by uncertainty about the goal, suggesting that hippocampal representations reflect ongoing deliberative planning processes. Overall, these results support a model in which internally generated hippocampal sequences are selected and updated according to the animal’s planned actions toward goals, and apparent tuning to external variables may arise because those variables correlate with action progression rather than being directly encoded.

Reference: Zutshi, I., Apostolelli, A., Yang, W., Zheng, Z. S., Dohi, T., Balzani, E., ... & Buzsáki, G. (2025). Hippocampal neuronal activity is aligned with action plans. Nature, 639(8053), 153-161.