Ho Yi-Yun, Yang Qiuwei, Boddu Priyanka, Bulkin David A, Warden Melissa R
Department of Neurobiology and Behavior, Cornell University, Ithaca, NY 14853, USA.
Cornell Neurotech, Cornell University, Ithaca, NY 14853, USA.
bioRxiv. 2024 Mar 24:2023.08.18.553864. doi: 10.1101/2023.08.18.553864.
The infralimbic cortex (IL) is essential for flexible behavioral responses to threatening environmental events. Reactive behaviors such as freezing or flight are adaptive in some contexts, but in others a strategic avoidance behavior may be more advantageous. IL has been implicated in avoidance, but the contribution of distinct IL neural subtypes with differing molecular identities and wiring patterns is poorly understood. Here, we study IL parvalbumin (PV) interneurons in mice as they engage in active avoidance behavior, a behavior in which mice must suppress freezing in order to move to safety. We find that activity in inhibitory PV neurons increases during movement to avoid the shock in this behavioral paradigm, and that PV activity during movement emerges after mice have experienced a single shock, prior to learning avoidance. PV neural activity does not change during movement toward cued rewards or during general locomotion in the open field, behavioral paradigms where freezing does not need to be suppressed to enable movement. Optogenetic suppression of PV neurons increases the duration of freezing and delays the onset of avoidance behavior, but does not affect movement toward rewards or general locomotion. These data provide evidence that IL PV neurons support strategic avoidance behavior by suppressing freezing.
边缘下皮质（IL）对于灵活应对威胁性环境事件的行为反应至关重要。诸如僵住或逃跑等反应性行为在某些情况下具有适应性，但在其他情况下，策略性回避行为可能更具优势。IL与回避行为有关，但不同分子特征和连接模式的不同IL神经亚型的作用却知之甚少。在这里，我们研究小鼠在进行主动回避行为时的IL小白蛋白（PV）中间神经元，在这种行为中，小鼠必须抑制僵住反应才能移动到安全地带。我们发现在这种行为范式中，为避免电击而移动期间，抑制性PV神经元的活动会增加，并且在小鼠经历单次电击后、学习回避行为之前，移动期间的PV活动就已出现。在向提示奖励移动期间或在旷场中的一般运动期间，PV神经活动不会改变，在这些行为范式中，不需要抑制僵住反应就能进行移动。对PV神经元进行光遗传学抑制会增加僵住的持续时间，并延迟回避行为的开始，但不会影响向奖励移动或一般运动。这些数据提供了证据，表明IL PV神经元通过抑制僵住反应来支持策略性回避行为。
