Carratalá-Ros Carla, López-Cruz Laura, Martínez-Verdú Andrea, Olivares-García Régulo, Salamone John D, Correa Mercè
Àrea de Psicobiologia, Universitat Jaume I, Castelló, Spain.
Behavioral Neuroscience Division, University of Connecticut, Storrs, CT, United States.
Front Behav Neurosci. 2021 Jul 9;15:700182. doi: 10.3389/fnbeh.2021.700182. eCollection 2021.
Impaired behavioral activation and effort-related motivational dysfunctions like fatigue and anergia are debilitating treatment-resistant symptoms of depression. Depressed people show a bias towards the selection of low effort activities. To determine if the broadly used antidepressant fluoxetine can improve behavioral activation and reverse dopamine (DA) depletion-induced anergia, male CD1 mice were evaluated for vigorous escape behaviors in an aversive context (forced swim test, FST), and also with an exercise preference choice task [running wheel (RW)-T-maze choice task]. In the FST, fluoxetine increased active behaviors (swimming, climbing) while reducing passive ones (immobility). However, fluoxetine was not effective at reducing anergia induced by the DA-depleting agent tetrabenazine, further decreasing vigorous climbing and increasing immobility. In the T-maze, fluoxetine alone produced the same pattern of effects as tetrabenazine. Moreover, fluoxetine did not reverse tetrabenazine-induced suppression of RW time but it reduced sucrose intake duration. This pattern of effects produced by fluoxetine in DA-depleted mice was dissimilar from devaluing food reinforcement by pre-feeding or making the food bitter since in both cases sucrose intake time was reduced but animals compensated by increasing time in the RW. Thus, fluoxetine improved escape in an aversive context but decreased relative preference for active reinforcement. Moreover, fluoxetine did not reverse the anergic effects of DA depletion. These results have implications for the use of fluoxetine for treating motivational symptoms such as anergia in depressed patients.
行为激活受损以及与努力相关的动机功能障碍(如疲劳和乏力)是抑郁症难以治疗的致残症状。抑郁症患者表现出对选择低努力活动的偏好。为了确定广泛使用的抗抑郁药氟西汀是否能改善行为激活并逆转多巴胺(DA)耗竭引起的乏力,对雄性CD1小鼠在厌恶情境下的剧烈逃避行为(强迫游泳试验,FST)以及运动偏好选择任务[跑步轮(RW)-T迷宫选择任务]进行了评估。在FST中,氟西汀增加了主动行为(游泳、攀爬),同时减少了被动行为(不动)。然而,氟西汀在减轻DA耗竭剂丁苯那嗪诱导的乏力方面无效,反而进一步降低了剧烈攀爬并增加了不动时间。在T迷宫中,单独使用氟西汀产生的效果模式与丁苯那嗪相同。此外,氟西汀并未逆转丁苯那嗪诱导的RW时间抑制,但它减少了蔗糖摄入持续时间。氟西汀在DA耗竭小鼠中产生的这种效果模式与通过预喂食使食物贬值或使食物变苦不同,因为在这两种情况下蔗糖摄入时间都减少了,但动物通过增加在RW中的时间来进行补偿。因此,氟西汀改善了在厌恶情境下的逃避行为,但降低了对主动强化的相对偏好。此外,氟西汀并未逆转DA耗竭的乏力效应。这些结果对氟西汀用于治疗抑郁症患者的动机症状(如乏力)具有启示意义。