Mucignat-Caretta Carla, Bondí Michela, Caretta Antonio
Department of Human Anatomy and Physiology, University of Padova, Via Marzolo 3, I-35131 Padova, Italy.
Physiol Behav. 2006 Dec 30;89(5):637-43. doi: 10.1016/j.physbeh.2006.08.003. Epub 2006 Sep 12.
Olfactory bulbectomy in rodents causes behavioral alterations, which result in a model of depression, validated for pharmacological screening of antidepressant drugs. To unravel the appearance and time course of the major behavioral effects which follow surgery, mice underwent olfactory bulb ablation or sham operation, and were analyzed after 1, 2, or 4 weeks. Bulbectomized (BX) mice were anosmic, and hyperactive when tested under stressful situations in the forced swimming test. Predatory aggression was upregulated in a time-dependent way: only after 4 weeks BX mice were faster than controls in attacking prey. At the same time, they were less aggressive against intruders; they did not differ from controls in open field exploration, but displayed a cognitive impairment in water maze. Behavioral tests thus indicated a marked hyperreactivity, a dissociation among different aggressive behaviors, and also a cognitive impairment induced by bulbectomy. Histological confirmation of the damage revealed that major modifications took place in the rostral pole of frontal lobes, with a significant increase in the width of the rostral migratory stream, 2 weeks after surgery, and in the subventricular zone, 4 weeks after surgery. These results suggest a base for the time-course of appearance of behavioral symptoms in BX mice.
对啮齿动物进行嗅球切除会导致行为改变，从而形成一种抑郁症模型，该模型已被验证可用于抗抑郁药物的药理学筛选。为了揭示手术后主要行为效应的出现情况和时间进程，对小鼠进行了嗅球切除或假手术，并在1周、2周或4周后进行分析。嗅球切除（BX）小鼠嗅觉丧失，在强迫游泳试验的应激情况下测试时表现为多动。掠夺性攻击以时间依赖性方式上调：仅在4周后，BX小鼠攻击猎物的速度比对照组快。与此同时，它们对入侵者的攻击性降低；它们在旷场探索中与对照组没有差异，但在水迷宫中表现出认知障碍。行为测试因此表明嗅球切除会导致明显的反应过度、不同攻击行为之间的分离以及认知障碍。损伤的组织学证实表明，主要变化发生在额叶的喙极，术后2周吻侧迁移流宽度显著增加，术后4周脑室下区显著增加。这些结果为BX小鼠行为症状出现的时间进程提供了依据。
