依托咪酯对大鼠空间学习记忆能力的影响

Effects of etomidate on spatial learning and memory ability of rats

目的研究依托咪酯对大鼠空间学习记忆能力的影响。方法将30只雄性Wistar大鼠随机分为空白组、对照组、实验组,每组10只。空白组予以腹腔注射0.9%Na Cl 2 m L,对照组予以腹腔注射脂肪乳剂2 m L,实验组予以腹腔注射5mg·kg^(-1)依托咪酯(根据小鼠的体重约2 m L)。用Morris水迷宫行为学实验评价依托咪酯对大鼠空间学习记忆力的影响。用全细胞膜片钳技术观察依托咪酯(相当于5μmol·L^(-1))脂肪乳剂30 m L对大鼠海马CA1区神经元延长时程抑制(LTD)的影响。结果大鼠腹腔注射依托咪酯后逃避潜伏期延长,第3天的逃避潜伏期:空白组为(74±9)s,对照组为(62±10)s,实验组为(157±14)s,与空白组比较,对照组和实验组的差异有统计学意义(P<0.001)。大鼠寻找平台的路径所需的游泳路径延长,第3天的寻找平台的路径:空白组为(1262±413)cm,对照组为(1482±267)cm,实验组为(3859±802)cm,与空白组比较,对照组和实验组的差异有统计学意义(P<0.001)。给予低频刺激前,突触后兴奋性电流(EPSC)的基线值:对照组、实验组、空白组分别为(1.01±0.13),(0.99±0.07),(1.00±0.10)m V;给予低频刺激后持续40 min,这3组的EPSC值分别为(0.59±0.04),(0.44±0.05),(0.78±0.06)m V,分别为基线值的(54.7±4.0)%,(39.9±3.0)%,(78.3±5.0)%。与低频刺激前比较,对照组和实验组差异有统计学意义(P<0.05)。结论依托咪酯反复多次的使用可使大鼠的空间学习记忆能力受到影响,机制可能是使LTD增强。

Objective To study the effect of etomidate on spatial learning and memory abilities in rats. Methods Thirty male Wistar rats were randomly divided into blank group, control group and test group, 10 rats in each group. The rats in test group were given intraperitoneal injec tion of 5 mg · kg^-1 etomidate （2 mL） , rats in control group received intraperitoneal injection of lipofundin （2 mL）, rats in blank group received saline intraperitoneally （2 mL）. The large in rats were evaluated by Morris water maze. （LTD） on rat hippocampal spatial learning and memory The long - term drepression CA1 neurons was investigated by whole -cell voltageclamp technique after given 30 μL etomidate （equivalent 5 μmol ± L^-1） lipofundin. Results After intraperitoneal injection of etomidate , the escape latency was prolonged, the escape latency in blank group was （74 ±9）s, the control group was （62 ± 10） s, the test group was （ 157 ± 14） s in the third day. Compared with blank group, there has statistically significant difference between control group and test group （P 〈 0. 001 ）. The swimming path was prolonged, the path of blank group was（ 1262 ±413）cm, the control group was （1482 ± 267 ）cm, the test group was （3859 ± 802）cm in the third day. Compared with blank group, there has statistically significant difference between control group and test group （P 〈0. 001 ）. The baseline value of postsynaptic excitatory current（EPSC） before given the low frequency stimulation in control, test, blank groups were （ 1.01 ± 0. 13 ）, （ 0. 99 ±. 0.07 ）, （ 1.00 ± 0. 10 ） mV. The value of EPSC after maintained the low frequency stimulation for 40 min in control, test, blank groups were （0. 59 ± 0.04 ）, （0. 44 ± 0. 05 ）, （0. 78 ± 0. 06 ） inV. That were （ 54. 7 ± 4 ） %, （ 39. 9 ± 3.0 ） %, （ 78.3 ± 5.0 ） % of the baseline values, respectively in three groups. Compared with before low frequency stimulation, there were difference in control, test groups （P 〈 0. 05 ）. Conchmion The etomidate repeated anesthesia or sedation may affect spatial learning and memory, and the anesthetic etomidate can enhance the expression of LTD, and its mechanism may affect the ability of spatial learning and memory in rats.