Whether transient or sustained neuronal activity during the delay period underlies working memory (WM) has been debated. Here, we report that transient, but not sustained, delay-period activity in mouse anterior agranular insular cortex (aAIC) plays a dominant role in maintaining WM information during learning of novel olfactory tasks. By optogenetic screening over 12 brain regions, we found that suppressing aAIC activity markedly impaired olfactory WM maintenance during learning. Single-unit recording showed that odor-selective aAIC neurons with predominantly transient firing patterns encoded WM information. Both WM task performance and transient-neuron proportion were enhanced and reduced by activating and suppressing the delay-period activity of the projection from medial prefrontal cortex (mPFC) to aAIC. The ability of mice to resist delay-period distractors also correlated with an increased percentage of transient neurons. Therefore, transient, but not sustained, aAIC neuronal activity during the delay period is largely responsible for maintaining information while learning novel WM tasks.

是否在延迟期内进行短暂或持续的神经元活动是工作记忆（WM）的基础，这一点一直存在争议。在这里，我们报告说，小鼠前颗粒状非小岛皮层皮质（aAIC）的短暂但非持续性延迟活动在学习新型嗅觉任务期间在维护WM信息中起着主导作用。通过对12个大脑区域的光遗传学筛选，我们发现抑制aAIC活性显着削弱了学习过程中嗅觉WM的维持。单单位记录表明，具有主要瞬态放电模式的气味选择性aAIC神经元编码WM信息。通过激活和抑制从内侧前额叶皮层（mPFC）到aAIC的投影的延迟期活动，可以增强和降低WM任务性能和瞬态神经元比例。小鼠抵抗延迟期干扰因素的能力也与瞬时神经元的百分比增加有关。因此，在延迟期间，短暂但非持续的aAIC神经元活动在学习新的WM任务时主要负责维护信息。