早年慢性应激后大鼠攻击行为及攻击相关脑区损伤

发布时间：2019-04-30 06:09

【摘要】：目的探索早年慢性应激对大鼠攻击行为及前额皮质、下丘脑和杏仁体神经元及突触的影响。方法 1雄性SD大鼠(出生后21天)60只，随机分为实验组、普通攻击组及对照组，每组15只，其余15只作为入侵鼠。(1)实验组：对早年大鼠进行慢性多种应激①社会孤养②日夜颠倒③去奖赏性挫败实验④激惹刺激实验⑤居住-入侵实验；(2)普通攻击组：仅居住-入侵实验；(3)对照组：常规饲养。 2行为学检测 2.1攻击行为检测(居住-入侵实验和中性环境实验) (1)攻击总数：撕咬次数+攀压次数+攻击性梳理次数+追逐次数； (2)攻击潜伏期：从拿出隔离的铁丝网到大鼠攻击入侵鼠的时间； (3)攻击持续时间：大鼠攻击入侵鼠的总时间； (4)攻击/威胁比：攻击总数和威胁(如对入侵鼠进行嘶叫、立毛等行为)次数； (5)攻击脆弱部位：大鼠对入侵鼠腹部、头部或喉部等部位的攻击； (6)对手屈服后继续攻击次数：当入侵鼠停止反抗后，大鼠仍对其攻击的次数。 2.2焦虑抑郁情绪检测(旷场试验) 3生物学检测 3.1tunel染色：使用该方法检测前额皮质、下丘脑和杏仁体神经元凋亡情况 3.2电镜：使用电镜观察三个脑区神经元凋亡结构及突触改变结果 1行为学检测结果：经过早年慢性应激后实验组青春期攻击性明显高于其余两组。居住-入侵实验攻击总数：实验组[(90.93±7.51)次]、普通攻击组[(16.47±4.12)次]及对照组[(5.00±3.09)次]之间差异有统计学意义(p0.01)。实验组攻击行为出现异常模式，如出现对手屈服后继续攻击和对对手脆弱部位进行攻击，且在中性环境下攻击性依然高于其余两组。实验组并未表现出明显焦虑抑郁情绪。 2生物学检测结果：tunel实验结果发现，实验组前额皮质神经元细胞凋亡水平高于其余两组(p0.01)。在电镜观察下，发现实验组前额皮质突触数密度及面密度均低于对照组(p0.05)，而其下丘脑和杏仁体神经元及突触未发现明显异常改变。结论 1.早年慢性多种应激后青春期大鼠攻击行为符合暴力行为标准； 2.早年慢性多种应激后青春期大鼠前额皮质神经元凋亡和突触改变； 3.早年慢性多种应激后青春期大鼠下丘脑和杏仁体神经元和突触损伤不明显。本研究结果提示早年慢性多种应激可能通过损伤前额皮质引起下丘脑和杏仁体功能脱抑制，最终导致暴力攻击行为发生。
[Abstract]:Aim to investigate the effects of early chronic stress on aggressive behavior, prefrontal cortex, hypothalamus and amygdala neurons and synapses in rats. Methods 1Sixty male SD rats (21 days after birth) were randomly divided into three groups: experimental group (n = 15), normal attack group (n = 15) and control group (n = 15). The other 15 rats were used as invading rats. (1) Experimental group: chronic multiple stress was carried out in early years of rats: 1 Social solitary feeding 2 night upside-down 3 reward frustration experiment 4 irritating stimulation experiment 5 living-invasion experiment; (2) ordinary attack group: dwelling-invasion experiment only; (3) control group: routine feeding. 2Behavioral detection 2.1 aggressive behavior test (habitation-invasion experiment and neutral environment experiment) (1) the total number of attacks: the number of bites, the times of pressure-climbing, the times of attack-carding, the times of chasing; (2) latent period of attack: from pulling out the isolated barbed wire to the time of the rat attacking the invading rat, (3) the duration of the attack: the total time of the rat attacking the invading rat; (4) attack / threat ratio: the total number of attacks and the number of threats (such as screaming, bristling, etc.) of invading rats; (5) attacking vulnerable parts: the attack of rats on the abdomen, head or throat of invading rats; (6) the number of attacks after the adversary succumbed: the number of attacks the rats still attacked when the invading rats stopped fighting. 2.2 anxiety and depression test (open field test) 3 Biological detection of 3.1tunel staining: use this method to detect prefrontal cortex, Apoptosis of hypothalamic and amygdala neurons 3.2 electron microscopy: observation of neuronal apoptosis structure and synaptic changes in three brain regions by electron microscopy: results of behavioral examination: after chronic stress in early years Adolescent aggression in the test group was significantly higher than that in the other two groups. The total number of residential-invasion attacks in the experimental group [(90.93 卤7.51) times], the common attack group [(16.47 卤4.12) times] and the control group [(5.00 卤3.09) times] had statistically significant differences (p 0.01). The attack behavior in the experimental group was abnormal, such as continuous attack after submission and attack on the vulnerable parts of the opponent, and the aggression in neutral environment was still higher than that in the other two groups. The experimental group did not show obvious anxiety and depression. 2Biological detection results: the results of tunel test showed that the apoptosis level of prefrontal cortex neurons in the experimental group was higher than that in the other two groups (p0.01). Under electron microscope, it was found that the number density and area density of synapses in prefrontal cortex of the experimental group were lower than those of the control group (p0.05), but no abnormal changes were found in the neurons and synapses of hypothalamus and amygdala in the experimental group. Conclusion 1. In the early years, the aggressive behavior of adolescent rats after chronic multiple stress was in accordance with the standard of violence; 2. Apoptosis and synaptic changes of prefrontal cortex neurons in prefrontal cortex of adolescent rats after chronic multiple stress in early years; 3. The injury of neurons and synapses in hypothalamus and amygdala was not obvious in adolescent rats after chronic multiple stress in early years. The results of this study suggest that chronic multiple stress in early years may cause depressing of hypothalamus and amygdala function through prefrontal cortex injury and ultimately lead to violent aggression.
【学位授予单位】：重庆医科大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：R749.5

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