Maintenance of the timing information in olfactory working memory by global activity waves

Working memory (WM) retains information during delay periods. How global neuronal activities maintain WM remains unclear. We recorded brain-wide activity via Neuropixels in mice performing a delay-varying olfactory WM task, to reveal animal’s capacity in maintaining both olfaction and duration information simultaneously. Neurons encoded WM information predominantly in transient patterns and generated cross-region activity waves, reflecting distinct cell assemblies that encoded olfaction-only, duration-only, or both information. The regional proportion of neurons and wave timing within cell assemblies were correlated with anatomical organization of the brain. Spike-correlogram analysis revealed stronger functional coupling within ten millisecond between neurons in a cell assembly, which could support activity waves through second-level activity loops. During training of artificial neural networks in classification tasks, accuracy is improved by using activity-wave constraints via local feedback inhibition. Thus, WM information could be maintained by global activity waves generated from cross-regional cell assemblies the brain. Our results might inspire new architecture of neural networks in maintaining multiple information.