Silva Carlos, Porter Blake S, Hillman Kristin L
Department of Psychology, Brain Health Research Centre, University of Otago, Dunedin, New Zealand.
Front Neurosci. 2021 Feb 26;15:643384. doi: 10.3389/fnins.2021.643384. eCollection 2021.
When performing tasks, animals must continually assess how much effort is being expended, and gage this against ever-changing physiological states. As effort costs mount, persisting in the task may be unwise. The anterior cingulate cortex (ACC) and the anterior insular cortex are implicated in this process of cost-benefit decision-making, yet their precise contributions toward driving effortful persistence are not well understood. Here we investigated whether electrical stimulation of the ACC or insular cortex would alter effortful persistence in a novel weightlifting task (WLT). In the WLT an animal is challenged to pull a rope 30 cm to trigger food reward dispensing. To make the action increasingly effortful, 45 g of weight is progressively added to the rope after every 10 successful pulls. The animal can quit the task at any point - with the rope weight at the time of quitting taken as the "break weight." Ten male Sprague-Dawley rats were implanted with stimulating electrodes in either the ACC [cingulate cortex area 1 (Cg1) in rodent] or anterior insula and then assessed in the WLT during stimulation. Low-frequency (10 Hz), high-frequency (130 Hz), and sham stimulations were performed. We predicted that low-frequency stimulation (LFS) of Cg1 in particular would increase persistence in the WLT. Contrary to our predictions, LFS of Cg1 resulted in shorter session duration, lower break weights, and fewer attempts on the break weight. High-frequency stimulation of Cg1 led to an increase in time spent off-task. LFS of the anterior insula was associated with a marginal increase in attempts on the break weight. Taken together our data suggest that stimulation of the rodent Cg1 during an effortful task alters certain aspects of effortful behavior, while insula stimulation has little effect.
在执行任务时，动物必须不断评估所付出的努力程度，并根据不断变化的生理状态进行衡量。随着努力成本的增加，坚持执行任务可能并不明智。前扣带回皮质（ACC）和前岛叶皮质参与了这种成本效益决策过程，但其对推动努力坚持的确切作用尚未得到充分理解。在这里，我们研究了对ACC或岛叶皮质进行电刺激是否会改变一项新颖的举重任务（WLT）中的努力坚持程度。在WLT中，动物面临拉动绳索30厘米以触发食物奖励发放的挑战。为了使动作越来越费力，每成功拉动10次后，会在绳索上逐渐增加45克的重量。动物可以在任何时候退出任务——退出时绳索上的重量被视为“突破重量”。十只雄性Sprague-Dawley大鼠在ACC[啮齿动物的扣带回皮质区域1（Cg1）]或前岛叶植入刺激电极，然后在刺激期间进行WLT评估。进行了低频（10赫兹）、高频（130赫兹）和假刺激。我们预测，特别是对Cg1进行低频刺激（LFS）会增加在WLT中的坚持程度。与我们的预测相反，Cg1的LFS导致实验持续时间缩短、突破重量降低以及对突破重量的尝试次数减少。对Cg1进行高频刺激导致非任务时间增加。对前岛叶进行LFS与对突破重量的尝试次数略有增加有关。综合我们的数据表明，在费力任务期间对啮齿动物的Cg1进行刺激会改变费力行为的某些方面，而对岛叶的刺激几乎没有影响。
