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  本文關(guān)鍵詞：視覺發(fā)育期大鼠視皮層錐體神經(jīng)細(xì)胞被動(dòng)膜特性研究　出處：《天津醫(yī)科大學(xué)》2012年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 突觸可塑性 視皮層 錐體神經(jīng)元 被動(dòng)膜特性 時(shí)間常數(shù) 細(xì)胞膜電阻

【摘要】：目的 研究Wistar大鼠初級(jí)視皮層第Ⅱ/Ⅲ層錐體神經(jīng)元被動(dòng)膜特性在視覺發(fā)育不同時(shí)期的變化規(guī)律,探討不同飼養(yǎng)條件下視覺經(jīng)驗(yàn)變化對(duì)被動(dòng)膜特性參數(shù)的影響。 方法 選取出生后14-60天健康SPF級(jí)Wistar大鼠,雌雄不限將其分成兩大組,一組在正常光照環(huán)境下飼養(yǎng)(12h白天/黑夜交替環(huán)境)；另一組從出生開始就放入全黑暗環(huán)境中飼養(yǎng)。再將每組分成五小組：視覺發(fā)育前關(guān)鍵期組(P13-15)；視覺發(fā)育關(guān)鍵期早期組(P16-20)；視覺發(fā)育關(guān)鍵期高峰期組(P25-27)；視覺發(fā)育關(guān)鍵期后期組(P30-35)；視覺發(fā)育后關(guān)鍵期組(P55-60)。應(yīng)用紅外微分干涉相差顯微鏡(IR-DIC)結(jié)合電耦合式攝像機(jī)(CCD-Camera),在可視法下應(yīng)用全細(xì)胞膜片鉗技術(shù)記錄：在電流鉗模式下,不做任何鉗制,使細(xì)胞保持在靜息電位,之后通過記錄電極注入40pA、持續(xù)時(shí)間為100ms的電流,反復(fù)十次,根據(jù)誘導(dǎo)的超級(jí)化電壓變化計(jì)算時(shí)間常數(shù)；在電壓鉗模式下,以-5mv為步階,記錄-50mv—-100mv及-100mv—-50mv的不同鉗制電位下電流的變化,從而計(jì)算出細(xì)胞膜電阻的不同變化趨勢(shì),觀察視覺發(fā)育不同階段以及不同飼養(yǎng)條件下大鼠視皮層神經(jīng)元被動(dòng)膜特性的變化規(guī)律。 結(jié)果 1.時(shí)間常數(shù)在兩種飼養(yǎng)條件下隨視覺發(fā)育的變化趨勢(shì)：正常條件飼養(yǎng)下p13-15組的時(shí)間常數(shù)(28.79±6.68ms)明顯大于p25-27組的時(shí)間常數(shù)(21.51±4.64ms)(P0.05,t=4.000)。而在暗飼養(yǎng)條件下,p13-15組的時(shí)間常數(shù)(38.71±6.04ms)也明顯大于p25-27組的時(shí)間常數(shù)(19.13±7.35ms)(P0.05,t=9.202)。時(shí)間常數(shù)隨視覺發(fā)育而下降。同時(shí),暗飼養(yǎng)條件下,p13-15組的時(shí)間常數(shù)(38.71±6.04ms)明顯大于正常條件飼養(yǎng)下p13-15組的時(shí)間常數(shù)(28.79±6.68ms)(P0.05,t=4.92)；但隨著生長發(fā)育,到視覺發(fā)育關(guān)鍵期時(shí),暗飼養(yǎng)條件下(19.13±7.35ms)與正常條件飼養(yǎng)下(21.51±4.64ms)的時(shí)間常數(shù),無明顯統(tǒng)計(jì)差異。 2.膜電阻在兩種飼養(yǎng)條件下隨視覺發(fā)育的變化趨勢(shì)：正常飼養(yǎng)環(huán)境下,p13-15組的膜電阻(131.03±40.78MΩ)明顯大與p16-20組的膜電阻(100.47±22.94MΩ)(P0.05,t=2.59)；同時(shí),p30-35組的膜電阻(82.38±20.43MΩ)明顯大于p55-60組的膜電阻(66.25±18.93MΩ)(P0.05,t=2.13),其他分組間雖無統(tǒng)計(jì)學(xué)差異,但膜電阻的整體趨勢(shì)表現(xiàn)為隨視覺發(fā)育而下降。而暗飼養(yǎng)環(huán)境下,膜電阻的整體趨勢(shì)也表現(xiàn)為隨視覺發(fā)育而下降。 3.膜電阻在不同鉗制電位下的變化趨勢(shì)：鉗制電位從-50MV—100MV時(shí),膜電阻都表現(xiàn)為由低到高的變化趨勢(shì)；當(dāng)鉗制電位從-100MV—50MV時(shí),膜電阻表現(xiàn)為由高到低的變化趨勢(shì)�？傊�,大鼠視皮層第二層錐體神經(jīng)元的膜電阻在去極化狀態(tài),電阻降低；而在超級(jí)化狀態(tài),電阻升高。 4.將視覺發(fā)育關(guān)鍵期前后所有年齡段的大鼠視皮層第二層錐體細(xì)胞的時(shí)間常數(shù)和膜電阻值作為兩個(gè)相關(guān)變量,應(yīng)用Pearson相關(guān)分析法進(jìn)行相關(guān)分析：相關(guān)系數(shù)r=0.275(P=0.033),二者具有正相關(guān)性：膜電阻值越大,時(shí)間常數(shù)越大。 結(jié)論 1、正常飼養(yǎng)和暗飼養(yǎng)兩種條件下,大鼠初級(jí)視皮層第Ⅱ/Ⅲ層錐體神經(jīng)元的被動(dòng)膜特性——時(shí)間常數(shù)和膜電阻,都具有相似的變化趨勢(shì),即都表現(xiàn)為隨視覺發(fā)育而逐漸下降。 2、本實(shí)驗(yàn)中同一時(shí)期暗飼養(yǎng)條件下的被動(dòng)膜特性數(shù)值雖高于正常飼養(yǎng)條件下的數(shù)值,但兩者的差異不具有統(tǒng)計(jì)學(xué)意義,提示年齡可能是影響被動(dòng)膜特性的決定性因素。 3.大鼠視皮層第Ⅱ/Ⅲ層錐體神經(jīng)元的膜電阻在去極化狀態(tài),電阻降低；而在超級(jí)化狀態(tài),電阻升高。 4.視覺發(fā)育關(guān)鍵期前后所有年齡段的大鼠視皮層第二層錐體細(xì)胞的時(shí)間常數(shù)和膜電阻值具有正相關(guān)性：膜電阻值越大,時(shí)間常數(shù)越大。
[Abstract]:objective
Objective to study the changes of passive membrane characteristics of Wistar / II pyramidal neurons in different stages of visual development, and to explore the effects of visual experience on passive membrane parameters under different feeding conditions.
Method
From postnatal day 14-60 healthy SPF Wistar rats, male and female will be divided into two groups, one group in normal light environment feeding (12h day / night alternating environment) and another group; from birth into the whole feeding dark environment. Then each group was divided into five groups: visual development front the key period group (P13-15); the critical period of visual development early group (P16-20); the peak of critical period of visual development group (P25-27); the critical period of visual development stage group (P30-35); after the critical period of visual development group (P55-60). The application of infrared differential interference contrast microscopy (IR-DIC) combined with electrical coupling camera (CCD-Camera) and using the whole cell patch clamp technique in visual method: in the current clamp mode, without any control, keeps cells in the resting potential after injected through the recording electrode of 40pA, duration of 100ms current, repeated ten times, according to the induced super Level of voltage change calculation time constant; in voltage clamp mode, -5mv step, the current changes in different holding potentials recorded -50mv - -100mv and -100mv - -50mv, to calculate the changing trend of cell membrane resistance, variation characteristics of passive film visual cortical neurons observed in different developmental stages and different visual the feeding conditions of rats.
Result
The 1. time constant in the two feeding conditions change with visual development conditions: normal feeding time constant of p13-15 group (28.79 + 6.68ms) time constant was significantly higher than that of p25-27 group (21.51 + 4.64ms) (P0.05, t=4.000). While in the dark rearing conditions, the time constant of p13-15 group (38.71. 6.04ms) time constant was significantly greater than group p25-27 (19.13 + 7.35ms) (P0.05, t=9.202). The time constant decreased with visual development. At the same time, dark rearing conditions, the time constant of the p13-15 group (38.71 + 6.04ms) time constant is significantly higher than the normal rearing conditions of group p13-15 (28.79 + 6.68ms (P0.05) t=4.92); but, with the development of the critical period of visual development, dark rearing conditions (19.13 + 7.35ms) with normal rearing conditions (21.51 + 4.64ms) time constant, no significant statistical difference.
The 2. film resistance in the two feeding conditions change with visual development environment: normal feeding, film resistance of group p13-15 (131.03 + 40.78M) significantly and p16-20 group of film resistance (100.47 + 22.94M) (P0.05, t=2.59); at the same time, the membrane resistance of p30-35 group (82.38 + 20.43M. The membrane resistance was significantly higher than that of p55-60) group (66.25 + 18.93M) (P0.05, t=2.13), although there was no statistically difference between other groups, but the overall trend of the membrane resistance is decreased with the visual development. Dark rearing environment, the overall trend of the membrane resistance as well as with the visual development and decline.
The change trend in different holding potentials of the 3. film resistance: holding potential from -50MV - 100MV, the membrane resistance from low to high trend; when the holding potential from -100MV to 50MV, the membrane resistance from high to low trend. In short, the rat visual cortical pyramidal neurons membrane resistance second in the depolarized state, reduce the resistance; and in the super state, the resistance increased.
4. before and after the critical period of visual development of all ages of rat optic time constant and the membrane resistance layer of pyramidal cells in cortex of second values as two dependent variables, using Pearson correlation analysis method for correlation analysis: correlation coefficient r=0.275 (P=0.033), two had positive correlation: the membrane resistance value is greater, the greater the time constant.
conclusion
1, under the two conditions of normal feeding and dark feeding, the passive membrane characteristics of the second / third tier pyramidal neurons of primary visual cortex in rats showed similar trend of time and membrane resistance, which all showed gradual decrease with visual development.
2, in this experiment, the passive membrane characteristics of dark feeding under the same period were higher than that of normal feeding conditions, but the difference between them was not statistically significant, suggesting that age may be the decisive factor affecting the passive membrane characteristics.
The membrane resistance of the second / third layer pyramidal neurons in the visual cortex of 3. rats was depolarized and the resistance decreased, while the resistance was elevated in the superchemical state.
4. there was a positive correlation between the time constant and the membrane resistance value of the second pyramidal cells in the visual cortex of all age groups before and after the critical period of visual development: the greater the membrane resistance, the greater the time constant.

【學(xué)位授予單位】：天津醫(yī)科大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2012
【分類號(hào)】：R77

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本文編號(hào)：1435019