Streptavidin包被的量子點(diǎn)慢性暴露對(duì)大鼠海馬突觸可塑性的影
發(fā)布時(shí)間：2018-08-14 11:37
【摘要】：量子點(diǎn)由于具卓越的理化性質(zhì),小尺寸效應(yīng)、表面效應(yīng)、量子尺寸效應(yīng)、宏觀量子隧道效應(yīng)等。所以被廣泛地應(yīng)用在電子、光學(xué)、磁學(xué)、能源化工、生物醫(yī)學(xué)、環(huán)境保護(hù)和納米微加工技術(shù)等各大領(lǐng)域。但是,隨著量子點(diǎn)的產(chǎn)業(yè)化進(jìn)程,在不久的將來,量子點(diǎn)的大規(guī)模投入生產(chǎn)以及日益廣泛應(yīng)用,很有可能大大增加人們接觸到并暴露在量子點(diǎn)的環(huán)境中的機(jī)會(huì)。因此急需展開有關(guān)量子點(diǎn)生物安全性及其潛在危害的研究。 多年來的研究表明,海馬是學(xué)習(xí)記憶的主要部位,海馬結(jié)構(gòu)廣泛參與了學(xué)習(xí)與記憶,而突觸可塑性是學(xué)習(xí)與記憶的細(xì)胞和分子基礎(chǔ)。所以,我們選擇了大鼠海馬作為切入點(diǎn)研究Streptavidin包被的量子點(diǎn)慢性暴露對(duì)輸入-輸出曲線(I/O)、雙脈沖易化(PPF)和長時(shí)程增強(qiáng)(LTP)的影響。 1、0.5 nM strep-CdSe/ZnS QD慢性暴露組動(dòng)物的fEPSP和PS I/O曲線與對(duì)照組無顯著性差異;10 nM strep-CdSe/ZnS QD慢性暴露能夠顯著增強(qiáng)大鼠海馬DG區(qū)I/O的PS幅度和fEPSP斜率的幅度,大鼠海馬DG區(qū)的基礎(chǔ)突觸傳遞得到了增強(qiáng),我們前期的工作也證實(shí)了原代培養(yǎng)的海馬神經(jīng)元中加入高濃度的量子點(diǎn)后,其鈣離子濃度顯著升高,有助于提高某些神經(jīng)遞質(zhì)的釋放和增強(qiáng)突觸后的反應(yīng),可能導(dǎo)致慢性高濃度量子點(diǎn)暴露引起基本突觸傳遞的增強(qiáng)。 2、PPF指的是當(dāng)一個(gè)突觸被一短暫間隔的雙脈沖刺激后,第二個(gè)反應(yīng)會(huì)明顯強(qiáng)于第一個(gè)反應(yīng)的現(xiàn)象,描述的是一種短時(shí)程突觸可塑性。這個(gè)現(xiàn)象部分歸因于第二次刺激引起的神經(jīng)遞質(zhì)的釋放量增加,另外DG區(qū)的PS的PPF源于突觸后的原因比突觸前的調(diào)節(jié)更為重要。在本實(shí)驗(yàn)中我們發(fā)現(xiàn),慢性量子點(diǎn)暴露無論是在0.5nM濃度下暴露還是在10nM濃度下暴露都顯著地降低了PPF的峰值,這說明慢性量子點(diǎn)暴露損傷了大鼠海馬DG區(qū)的短時(shí)程突觸可塑性。 3、LTP是一種典型活動(dòng)依賴性的突觸可塑性的電生理模型,是公認(rèn)的學(xué)習(xí)與記憶活動(dòng)的細(xì)胞分子生物學(xué)基礎(chǔ)。我們的實(shí)驗(yàn)結(jié)果表明, 0.5 nM strep-CdSe/ZnS QD慢性量子點(diǎn)暴露顯著降低了EPSP和PS的LTP,10 nM strep-CdSe/ZnS QD量子點(diǎn)慢性暴露對(duì)LTP抑制的更為嚴(yán)重。這說明慢性量子點(diǎn)暴露損傷了大鼠海馬DG區(qū)長時(shí)程的突觸可塑性。這種突觸可塑性損傷可能與Cd~2+的釋放、氧化應(yīng)激等因素有關(guān)。具體機(jī)制還有待于進(jìn)一步的研究。
[Abstract]:Quantum dots have excellent physical and chemical properties, small size effect, surface effect, quantum size effect, macroscopic quantum tunneling effect and so on. So it is widely used in many fields, such as electronics, optics, magnetism, energy and chemical industry, biomedicine, environmental protection and nanotechnology. However, with the industrialization of quantum dots, in the near future, the large-scale production and increasingly widespread application of quantum dots, it is likely to greatly increase people's exposure to and exposure to the environment of quantum dots. Therefore, it is urgent to study the biological safety and potential hazards of quantum dots. Over the years studies have shown that the hippocampus is the main site of learning and memory, the hippocampal structure is widely involved in learning and memory, and synaptic plasticity is the cellular and molecular basis of learning and memory. So. We selected the hippocampus of rats as a starting point to study the effects of chronic exposure to Streptavidin coated QDs on I / O curves, double pulse facilitation (PPF) and long duration enhanced (LTP). 1nM strep-CdSe/ZnS QD chronic exposure group animals were selected to study the effects of chronic exposure to QDs coated with Streptavidin on the input-output curve (I / O), double pulse facilitation (PPF) and long-term enhanced (LTP). There was no significant difference in fEPSP and PS I / O curves between the control group and the control group. Chronic exposure to 10 nm strep-CdSe/ZnS QD could significantly increase the amplitude of PS and fEPSP slope of I / O in rat hippocampal DG region. The basic synaptic transmission in rat hippocampal DG region was enhanced. Our previous work also confirmed that the calcium concentration of primary cultured hippocampal neurons increased significantly after the addition of high concentration quantum dots. To increase the release of certain neurotransmitters and enhance postsynaptic responses, PPF refers to the fact that when a synapse is stimulated by a short interval of double pulses, the second response is significantly stronger than the first. A short-term synaptic plasticity is described. This phenomenon is partly due to the increase in the release of neurotransmitters induced by the second stimulation, and the postsynaptic PPF in the DG region is more important than the pre-synaptic regulation. In this study, we found that chronic quantum dot exposure significantly reduced the peak value of PPF both at 0.5nM concentration and 10nM concentration. This suggests that chronic quantum dot exposure injures short-term synaptic plasticity in rat hippocampal DG region. 3 LTP is a typical activity dependent electrophysiological model of synaptic plasticity. It is recognized as the basis of cellular and molecular biology for learning and memory activities. Our experimental results show that the chronic QD exposure of 0.5 nm strep-CdSe/ZnS QD significantly reduces the inhibition of LTP by EPSP and PS LTP10nM strep-CdSe/ZnS QD QD QDs. This suggests that chronic quantum dot exposure injures synaptic plasticity in the long-term DG region of rat hippocampus. This synaptic plasticity may be related to the release of Cd~2, oxidative stress and other factors. The specific mechanism remains to be further studied.
【學(xué)位授予單位】：中國科學(xué)技術(shù)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2011
【分類號(hào)】：R346
本文編號(hào)：2182735
[Abstract]:Quantum dots have excellent physical and chemical properties, small size effect, surface effect, quantum size effect, macroscopic quantum tunneling effect and so on. So it is widely used in many fields, such as electronics, optics, magnetism, energy and chemical industry, biomedicine, environmental protection and nanotechnology. However, with the industrialization of quantum dots, in the near future, the large-scale production and increasingly widespread application of quantum dots, it is likely to greatly increase people's exposure to and exposure to the environment of quantum dots. Therefore, it is urgent to study the biological safety and potential hazards of quantum dots. Over the years studies have shown that the hippocampus is the main site of learning and memory, the hippocampal structure is widely involved in learning and memory, and synaptic plasticity is the cellular and molecular basis of learning and memory. So. We selected the hippocampus of rats as a starting point to study the effects of chronic exposure to Streptavidin coated QDs on I / O curves, double pulse facilitation (PPF) and long duration enhanced (LTP). 1nM strep-CdSe/ZnS QD chronic exposure group animals were selected to study the effects of chronic exposure to QDs coated with Streptavidin on the input-output curve (I / O), double pulse facilitation (PPF) and long-term enhanced (LTP). There was no significant difference in fEPSP and PS I / O curves between the control group and the control group. Chronic exposure to 10 nm strep-CdSe/ZnS QD could significantly increase the amplitude of PS and fEPSP slope of I / O in rat hippocampal DG region. The basic synaptic transmission in rat hippocampal DG region was enhanced. Our previous work also confirmed that the calcium concentration of primary cultured hippocampal neurons increased significantly after the addition of high concentration quantum dots. To increase the release of certain neurotransmitters and enhance postsynaptic responses, PPF refers to the fact that when a synapse is stimulated by a short interval of double pulses, the second response is significantly stronger than the first. A short-term synaptic plasticity is described. This phenomenon is partly due to the increase in the release of neurotransmitters induced by the second stimulation, and the postsynaptic PPF in the DG region is more important than the pre-synaptic regulation. In this study, we found that chronic quantum dot exposure significantly reduced the peak value of PPF both at 0.5nM concentration and 10nM concentration. This suggests that chronic quantum dot exposure injures short-term synaptic plasticity in rat hippocampal DG region. 3 LTP is a typical activity dependent electrophysiological model of synaptic plasticity. It is recognized as the basis of cellular and molecular biology for learning and memory activities. Our experimental results show that the chronic QD exposure of 0.5 nm strep-CdSe/ZnS QD significantly reduces the inhibition of LTP by EPSP and PS LTP10nM strep-CdSe/ZnS QD QD QDs. This suggests that chronic quantum dot exposure injures synaptic plasticity in the long-term DG region of rat hippocampus. This synaptic plasticity may be related to the release of Cd~2, oxidative stress and other factors. The specific mechanism remains to be further studied.
【學(xué)位授予單位】：中國科學(xué)技術(shù)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2011
【分類號(hào)】：R346
【參考文獻(xiàn)】
相關(guān)期刊論文 前2條
1 劉舒曼,徐征,H.Wageh,徐敘tb;CdSe/CdS核/殼型納米晶的光譜特性[J];光譜學(xué)與光譜分析;2002年06期
2 張慶彬;宋凱;孔祥貴;曾慶輝;張友林;孫雅娟;劉曉敏;;CdSe/ZnSe量子點(diǎn)在油水兩相體系下的聚合物包覆相轉(zhuǎn)移及其光譜表征[J];光譜學(xué)與光譜分析;2010年02期
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