大鼠內(nèi)側(cè)內(nèi)嗅皮層淺層主要神經(jīng)元的特性
發(fā)布時(shí)間：2018-11-23 09:54
【摘要】：記憶可分為海馬依賴性和海馬非依賴性記憶，海馬環(huán)路在海馬依賴性記憶中發(fā)揮著重要作用[1]，作為海馬結(jié)構(gòu)的輸入與輸出中繼站的內(nèi)嗅皮層在海馬與大腦新皮質(zhì)之間起著信息的雙向傳遞作用。錐體神經(jīng)元和星型神經(jīng)元是內(nèi)側(cè)內(nèi)嗅皮層淺層中是主要的投射神經(jīng)元。大腦皮層(包括嗅周皮質(zhì)，聯(lián)合皮質(zhì)以及海馬旁回皮質(zhì))的信息主要傳入EC的淺層神經(jīng)元，然后通過它們將這些高度處理的感覺信息傳遞至海馬結(jié)構(gòu)記憶環(huán)路。目前，許多的實(shí)驗(yàn)證明EC不僅在新皮質(zhì)-海馬對(duì)話中起重要作用，而且還主動(dòng)參與了記憶的鞏固和提取。所以，在了解MEC淺層主要神經(jīng)元基本形態(tài)基礎(chǔ)后，進(jìn)而研究其基本電生理指標(biāo)將可以幫助我們科學(xué)區(qū)分內(nèi)嗅皮層淺層的兩類神經(jīng)元和了解MEC區(qū)在人腦的學(xué)習(xí)記憶過程中所擔(dān)任的角色，進(jìn)而為下步研究麻醉藥物在MEC區(qū)的作用靶點(diǎn)提供實(shí)驗(yàn)依據(jù)。 在本次研究中，我們主要采用高爾基嗜銀染色和體外腦片膜片鉗技術(shù)相結(jié)合的方法來研究?jī)?nèi)側(cè)內(nèi)嗅皮層淺層錐體神經(jīng)元和星型神經(jīng)元的形態(tài)學(xué)特征和基本電生理特性：首先通過借助紅外干涉相差(IR-DIC)顯微鏡的幫助，我們初步觀察內(nèi)側(cè)內(nèi)嗅皮層淺層錐體神經(jīng)元和星形神經(jīng)元的形態(tài)特征；并在此基礎(chǔ)上，我們使用高爾基嗜銀染色技術(shù)手段對(duì)內(nèi)嗅皮層中細(xì)胞構(gòu)筑和纖維聯(lián)系進(jìn)行了研究；在此基礎(chǔ)上我們可以通過形態(tài)來對(duì)細(xì)胞進(jìn)行分類，并通過離體腦片膜片鉗技術(shù)，來研究各類細(xì)胞在不同的刺激條件下的電生理反應(yīng)，依此得出各自的基本電生理特性，最后通過比較分析找出各自的差異所在。 通過實(shí)驗(yàn)我們了解到：MEC區(qū)淺層錐體細(xì)胞和星型細(xì)胞無論在形態(tài)學(xué)，還是基本電生理均存在較大差異。星型細(xì)胞呈方枕狀，，其胞體發(fā)出多個(gè)主樹突；而錐體神經(jīng)元主要呈三角型，其胞體只有一個(gè)主樹突和幾個(gè)次要基樹突穿出，而且細(xì)胞體積明顯較星型神經(jīng)元��；進(jìn)一步離體腦片膜片鉗實(shí)驗(yàn)，我們發(fā)現(xiàn)：兩類神經(jīng)元靜息膜電位相近，但相比于星型神經(jīng)元，錐體神經(jīng)元具有更高的細(xì)胞興奮性，即在相同的刺激電流下，錐體神經(jīng)元更易發(fā)放。文獻(xiàn)指出這種細(xì)胞興奮性的差異源于兩類神經(jīng)元胞體高電壓閾值激活的鈣離子通道密度差異所致，這也就解釋了為什么部分癲癇病人癲癇持續(xù)發(fā)作后EC區(qū)錐體神經(jīng)元會(huì)發(fā)生選擇性死亡；在注入-160pA的超極化電流觀察HCN通道激活所產(chǎn)生電位“Sag”和“Ih”電流的實(shí)驗(yàn)過程中，我們發(fā)現(xiàn)在星型細(xì)胞上所記錄的電信號(hào)明顯大于錐體細(xì)胞，結(jié)合實(shí)驗(yàn)記錄模式和生物電信號(hào)在胞膜傳遞的衰減因素，我們初步考慮這種差異源自于HCN通道分布差異：在星型細(xì)胞中HCN主要集中于胞體，而對(duì)于錐體神經(jīng)元而言，則位于樹突的遠(yuǎn)端。
[Abstract]:Memory can be divided into hippocampal dependent and hippocampal independent memory. The hippocampal loop plays an important role in hippocampal dependent memory [1]. The entorhinal cortex, which acts as an input and output relay for the hippocampal formation, plays a two-way role in the transmission of information between the hippocampus and the neocortex of the brain. Pyramidal neurons and star neurons are the main projective neurons in the superficial layer of the medial olfactory cortex. The information of cerebral cortex (including periolfactory cortex, associative cortex and para-hippocampal cortex) is mainly transmitted to the superficial neurons of EC, and then these highly processed sensory information are transmitted to the hippocampal structure memory loop. At present, many experiments have proved that EC not only plays an important role in neocortex-hippocampal dialogue, but also actively participates in the consolidation and extraction of memory. So, after understanding the basic morphological basis of the main neurons in the shallow layer of MEC, The study of its basic electrophysiological parameters will help us scientifically distinguish between two types of neurons in the superficial layer of the olfactory cortex and understand the role of the MEC region in the learning and memory process of the human brain. It provides the experimental basis for the next step to study the action targets of narcotic drugs in MEC region. In this study, We studied the morphological and basic electrophysiological characteristics of the superficial pyramidal neurons and star neurons in the medial olfactory cortex by using Golgi silver staining and patch clamp technique in vitro. Firstly, we studied the morphological and electrophysiological characteristics of the superficial pyramidal neurons and star neurons in the medial olfactory cortex. With the help of infrared interference phase contrast (IR-DIC) microscope, The morphological characteristics of superficial pyramidal neurons and star neurons in the medial olfactory cortex were preliminarily observed. On this basis, we used Golgi silver staining technique to study cell architecture and fiber connections in the endolfactory cortex. On this basis, we can classify the cells by morphology, and study the electrophysiological responses of all kinds of cells under different stimulation conditions by using in vitro patch clamp technology, so as to obtain their basic electrophysiological characteristics. Finally, through comparative analysis to find out their differences. We know that there are great differences in morphology and basic electrophysiology between superficial pyramidal cells and star cells in MEC region. The star cells were square occipital-shaped, and the pyramidal neurons were mainly triangular in shape, with only one main dendrite and several secondary basal dendrites perforated, and the cell volume was obviously smaller than that of the star-shaped neurons. Further in vitro patch clamp experiments, we found that the resting membrane potentials of the two types of neurons are similar, but the pyramidal neurons have higher cell excitability than star neurons, that is, under the same stimulation current, Pyramidal neurons are easier to release. It is suggested that the difference in excitability of these two types of neurons is due to the difference in the density of calcium channels activated by high voltage threshold in the cell body of two kinds of neurons. This may explain the selective death of EC pyramidal neurons in some epileptic patients after a sustained seizure. In the experiment of observing the "Sag" and "Ih" currents generated by the activation of HCN channels, we found that the electrical signals recorded on star cells were significantly larger than those in pyramidal cells. Considering the attenuation factors of experimental recording mode and bioelectrical signal transmission in the cell membrane, we preliminarily consider that this difference originates from the difference in the distribution of HCN channels: in star cells, HCN is mainly concentrated in the cell body, but for pyramidal neurons, Is located at the distal end of the dendrite.
【學(xué)位授予單位】：第三軍醫(yī)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：R614
本文編號(hào)：2351155
[Abstract]:Memory can be divided into hippocampal dependent and hippocampal independent memory. The hippocampal loop plays an important role in hippocampal dependent memory [1]. The entorhinal cortex, which acts as an input and output relay for the hippocampal formation, plays a two-way role in the transmission of information between the hippocampus and the neocortex of the brain. Pyramidal neurons and star neurons are the main projective neurons in the superficial layer of the medial olfactory cortex. The information of cerebral cortex (including periolfactory cortex, associative cortex and para-hippocampal cortex) is mainly transmitted to the superficial neurons of EC, and then these highly processed sensory information are transmitted to the hippocampal structure memory loop. At present, many experiments have proved that EC not only plays an important role in neocortex-hippocampal dialogue, but also actively participates in the consolidation and extraction of memory. So, after understanding the basic morphological basis of the main neurons in the shallow layer of MEC, The study of its basic electrophysiological parameters will help us scientifically distinguish between two types of neurons in the superficial layer of the olfactory cortex and understand the role of the MEC region in the learning and memory process of the human brain. It provides the experimental basis for the next step to study the action targets of narcotic drugs in MEC region. In this study, We studied the morphological and basic electrophysiological characteristics of the superficial pyramidal neurons and star neurons in the medial olfactory cortex by using Golgi silver staining and patch clamp technique in vitro. Firstly, we studied the morphological and electrophysiological characteristics of the superficial pyramidal neurons and star neurons in the medial olfactory cortex. With the help of infrared interference phase contrast (IR-DIC) microscope, The morphological characteristics of superficial pyramidal neurons and star neurons in the medial olfactory cortex were preliminarily observed. On this basis, we used Golgi silver staining technique to study cell architecture and fiber connections in the endolfactory cortex. On this basis, we can classify the cells by morphology, and study the electrophysiological responses of all kinds of cells under different stimulation conditions by using in vitro patch clamp technology, so as to obtain their basic electrophysiological characteristics. Finally, through comparative analysis to find out their differences. We know that there are great differences in morphology and basic electrophysiology between superficial pyramidal cells and star cells in MEC region. The star cells were square occipital-shaped, and the pyramidal neurons were mainly triangular in shape, with only one main dendrite and several secondary basal dendrites perforated, and the cell volume was obviously smaller than that of the star-shaped neurons. Further in vitro patch clamp experiments, we found that the resting membrane potentials of the two types of neurons are similar, but the pyramidal neurons have higher cell excitability than star neurons, that is, under the same stimulation current, Pyramidal neurons are easier to release. It is suggested that the difference in excitability of these two types of neurons is due to the difference in the density of calcium channels activated by high voltage threshold in the cell body of two kinds of neurons. This may explain the selective death of EC pyramidal neurons in some epileptic patients after a sustained seizure. In the experiment of observing the "Sag" and "Ih" currents generated by the activation of HCN channels, we found that the electrical signals recorded on star cells were significantly larger than those in pyramidal cells. Considering the attenuation factors of experimental recording mode and bioelectrical signal transmission in the cell membrane, we preliminarily consider that this difference originates from the difference in the distribution of HCN channels: in star cells, HCN is mainly concentrated in the cell body, but for pyramidal neurons, Is located at the distal end of the dendrite.
【學(xué)位授予單位】：第三軍醫(yī)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：R614
【參考文獻(xiàn)】
相關(guān)期刊論文 前1條
1 喻欣;郭蓮軍;殷光甫;宗賢剛;艾永循;;Effect of Non-specific HCN_1 Blocker CsCl on Spatial Learning and Memory in Mouse[J];華中科技大學(xué)學(xué)報(bào)(醫(yī)學(xué)英德文版);2006年02期
本文編號(hào)：2351155
本文鏈接：http://sikaile.net/yixuelunwen/mazuiyixuelunwen/2351155.html
最近更新
教材專著
