本文選題：大鼠 + Y迷宮工作記憶�。� 參考：《天津醫(yī)科大學》2014年博士論文

【摘要】：研究目的： 工作記憶(WM)是一類重要的記憶,在許多復雜認知功能中起了重要作用。工作記憶機制的研究是神經(jīng)科學和認知科學的前沿科學問題。本研究的科學問題為不同模態(tài)神經(jīng)信號如何協(xié)同編碼工作記憶的機制,包括：(1)局部場電位(local field potentials,LFPs)中與工作記憶相關的主要頻率分量,0分量(4-12Hz)和γ分量(30-100Hz)協(xié)同編碼工作記憶的機制；(2)鋒電位(spikes)和局部場電位(LFPs)協(xié)同編碼工作記憶的機制。 研究方法： (1)工作記憶不同模態(tài)神經(jīng)信號的獲取： 本論文中,以SD大鼠在Y迷宮的工作記憶為研究對象,應用在體植入式多通道微電極記錄技術,在大鼠內側前額葉皮層記錄神經(jīng)電活動的時空序列,從中獲取LFPs和spikes的時空序列。應用時頻從能量分布分析LFPs在WM的主要頻段：0、γ,應用帶通濾波獲取LFPs的θ分量和γ分量。 (2)LFPs的θ和γ頻率分量協(xié)同編碼工作記憶： 采用相位-幅值交叉頻率匹配的方法,分別計算定量表征各個通道LFPs中工作記憶相關頻段θ、γ分量協(xié)同性強度的頻率調制指數(shù)MI。對4-100Hz的LFPs信號進行帶寬為4Hz,移動步長為2Hz的帶通濾波,計算定量表征各頻帶信號之間調制強度的調制指數(shù),繪制相位-幅值頻率調制強度分布圖。計算0分量、Y分量之間調制強度在工作記憶中的動態(tài)變化。(3)LFPs和spikes協(xié)同編碼工作記憶： 基于聯(lián)合熵計算spikes與LFPs工作記憶相關分量(θ、γ分量)的聯(lián)合熵指數(shù)(j oint entropy index, JEI),定量表征大鼠工作記憶過程中spikes-LFPs相關分量協(xié)同性強度。分別計算工作記憶過程中,動態(tài)變化spikes-θ、spikes-低頻γ和spikes-高頻γ分量JEI值,分析spikes-LFPs協(xié)同編碼的特征模式。 研究結果： (1)工作記憶過程中LFPs時頻分布 在6只大鼠工作記憶過程中,LFPs中低頻部分(20Hz)能量高于高頻部分能量。在1號到5號大鼠中,θ、γ頻帶信號的峰值出現(xiàn)在工作記憶參考點前1s內,在6號大鼠中,θ、γ頻帶信號的峰值出現(xiàn)在工作記憶參考點前1s附近。 (2)LFPs的0-γ對工作記憶的協(xié)同編碼 1)基于窄帶濾波的LFPs不同頻率分量調制強度分布 LFPs信號不同頻率分量之間調制強度雙峰值分別出現(xiàn)在低頻信號(4-10Hz)的相位與高頻信號幅值(45Hz和80Hz附近)之間。根據(jù)調制指數(shù)峰值分布情況,將在γ頻帶進一步劃分為低頻γ(γL,30-60Hz)和高頻γ(γH：60-100Hz)。較高頻率信號(20-100Hz)的相位與4-100Hz頻率范圍內的窄帶LFPs信號(帶寬：4Hz,移動步長：2Hz)的幅值之間不存在調制作用。 2)LFPs的θγL對工作記憶的協(xié)同編碼 大鼠前額葉皮層LFPs信號的θ-γL調制指數(shù)值在工作記憶過程中動態(tài)變化(4只大鼠,共63次實驗)。在大鼠行為學正確時,θ-γL之間調制強度在工作記憶過程中顯著增加。同時,行為學正確的工作記憶任務中,θ-γL調制強度峰值顯著高于行為學錯誤時兩者調制強度。 3)LFPs的θ-γH對工作記憶的協(xié)同編碼 在行為學正確的實驗中,大鼠前額葉皮層LFPs信號θ-γH之間調制指數(shù)值在工作記憶過程中無顯著變化(4只大鼠,共63次實驗)。同時,行為學正確的實驗中不同任務時期LFPs θ-γH之間的調制強度與錯誤實驗中相應任務時期調制指數(shù)值之間不存在統(tǒng)計學差異。 4)工作記憶過程中,16通道LFPs的θ-γL調制強度動態(tài)變化 工作記憶過程中,16通道LFPs的0信號與低頻γ信號之間的調制強度變化存在差異性。在大鼠行為學正確的實驗中,多數(shù)通道中0信號與低頻γ信號之間的調制作用強度顯著增強,但不是所有通道。 (3)Spikes-LFPs對工作記憶的協(xié)同編碼 1)Spikes-LFPs的θ分量對工作記憶的協(xié)同編碼 對工作記憶過程中,6只大鼠各10次實驗歸一化spikes-LFPs的0分量JEIs值進行平均。結果顯示,兩者的歸一化JEIs值由工作記憶參考點前3s內的0.345±0.038(均值±標準誤),增加至工作記憶參考點前1s的最大值0.721±0.033(均值±標準誤),兩者之間的差異具有統(tǒng)計學意義。對6只大鼠分別進行分析,結果顯示,6只大鼠中,工作記憶參考點前1s內spikes-0分量JEIs值均顯著升高。 2) Spikes-LFPs的γL分量對工作記憶的協(xié)同編碼 對工作記憶過程中,6只大鼠各10次實驗歸一化spikes-γL分量JEIs值進行平均,結果顯示,兩者的歸一化JEIs值由工作記憶參考點前3s內的0.408±0.040(均值±標準誤),增加至工作記憶參考點前1s的最大值0.696±0.040(均值±標準誤),兩者之間的差異具有統(tǒng)計學意義。 3) Spikes-LFPs的γH分量對工作記憶的協(xié)同編碼 對工作記憶過程中,6只大鼠各10次實驗歸一化spikes-YH分量JEIs值進行平均,結果顯示,兩者的歸一化JEIs值由工作記憶參考點前3s內的0.393±0.041(均值±標準誤),增加至工作記憶參考點前1s的最大值0.690±0.038(均值±標準誤),兩者之間的差異具有統(tǒng)計學意義。 研究結論 (1)工作記憶過程中,LFPs的θ、γ分量的能量顯著增加,為工作記憶主要頻率分量。 (2)大鼠前額葉皮層LFPs的θ分量和低頻γ分量調制強度在大鼠行為學正確的任務中顯著增強,兩者協(xié)同編碼了工作記憶。 (3)大鼠前額葉皮層spikes和LFPs的θ、Y分量協(xié)同編碼了工作記憶。在大鼠行為學正確的實驗中,6只大鼠前額葉皮層spikes和LFPs工作記憶相關分量(0,低頻γ和高頻γ)的協(xié)同性均顯著增強并在工作記憶參考點前達到峰值。
[Abstract]:Purpose of study :

Working memory ( WM ) is a kind of important memory , plays an important role in many complex cognitive functions . The research of working memory mechanism is the forward - science problem of neuroscience and cognitive science . The scientific problem of this study is how to co - encode working memory in different modal neural signals , including : ( 1 ) the mechanism of cooperative coding of working memory with the main frequency components , 0 components ( 4 - 12 Hz ) and gamma components ( 30 - 100Hz ) related to working memory in local field potentials ( LFPs ) ;
( 2 ) The mechanism of cooperative coding of working memory with frontal potential and local field potential ( LFPs ) .

Study method :

( 1 ) obtaining the neural signals of different modes of working memory :

In this paper , the spatial - temporal sequence of neural electrical activity was recorded on the medial frontal cortex of rats with the working memory of the Y maze in SD rats . The temporal and temporal sequences of LFPs and LFPs were obtained from the energy distribution analysis LFPs in the main frequency bands of WM : 0 , 緯 , and the 胃 and 緯 components of LFPs were obtained by band - pass filtering .

( 2 ) the theta and gamma frequency components of LFPs cooperatively encode the working memory :

A method for quantitatively characterizing the frequency modulation index MI of working memory related frequency band 胃 and 緯 component coordination intensity in each channel LFPs is calculated by using phase - amplitude cross frequency matching method . The frequency modulation index of the modulation intensity between each frequency band signal is calculated and quantitatively characterized by band - pass filtering with 4 - 100Hz bandwidth of 4Hz and moving step size of 2Hz . The dynamic change of modulation intensity between the 0 and Y components is calculated .

A joint entropy index ( JEI ) of the correlation component ( 胃 , 緯 component ) of the working memory of LFPs was calculated based on the combined entropy .

Results of the study :

( 1 ) Frequency distribution of LFPs in working memory

In the course of working memory of 6 rats , the energy of low frequency part ( 20Hz ) in LFPs was higher than that of high frequency partial energy . In rats 1 to 5 , the peak value of the signal of 胃 and 緯 band appeared within 1 s of the reference point of working memory , and the peak value of the signal of 胃 and 緯 band appeared in the vicinity of the first 1s of working memory reference point .

( 2 ) Co - coding of Working Memory by 0 - 緯 of LFPs

1 ) modulation intensity distribution of different frequency components of LFPs based on narrowband filtering

The two peaks of the modulation intensity between different frequency components of the LFPs signal appear between the phase of the low frequency signal ( 4 - 10 Hz ) and the high frequency signal amplitude ( near 45 Hz and 80 Hz ) , respectively . According to the distribution of the peak distribution of the modulation index , the frequency band is further divided into low frequency . gamma . ( . gamma . L , 30 - 60 Hz ) and high frequency gamma ( . gamma . H : 60 - 100 Hz ) . There is no modulation effect between the phase of the higher frequency signal ( 20 - 100 Hz ) and the amplitude of the narrowband LFPs signal ( bandwidth : 4 Hz , moving step : 2 Hz ) in the 4 - 100 Hz frequency range .

2 ) Coencoding of 胃緯L of LFPs on Working Memory

The value of 胃 - 緯L modulation index of LFPs signal in rat frontal cortex was dynamically changed during working memory ( 4 rats , 63 experiments ) . In the correct behavior of rats , the modulation intensity between 胃 - 緯L increased significantly in the course of working memory . At the same time , in the correct working memory task , 胃 - 緯L modulation intensity peak was significantly higher than that of behavioral error .

3 ) The Synergistic Coding of 胃 - 緯H of LFPs on Working Memory

In the correct behavior experiment , there was no significant change in the modulation index between LFPs signal 胃 - 緯H in the frontal cortex of rats ( 4 rats , 63 experiments ) . At the same time , there is no statistical difference between the modulation intensity between LFPs 胃 - 緯H and the modulation index value in the wrong experiment .

4 ) Dynamic change of 胃 - 緯L modulation intensity of 16 - channel LFPs during working memory

In the course of working memory , there is a difference in modulation intensity between 0 - signal and low - frequency 緯 - signal in 16 - channel LFPs . In the correct experiment of rat behavior , the intensity of modulation between 0 - signal and low - frequency 緯 - signal in most channels is significantly enhanced , but not all channels .

( 3 ) Co - coding of Spikes - LFPs on Working Memory

1 ) Synergistic coding of theta component of Spikes - LFPs on working memory

The results showed that the normalized JEIs value was 0.345 鹵 0.038 ( mean 鹵 standard error ) within 3 seconds before the reference point of working memory and 0.721 鹵 0.033 ( mean 鹵 standard error ) in the first 1s of the reference point of working memory , and the difference between them was statistically significant .

2 ) Co - coding of the 緯L component of Spikes - LFPs on working memory

In the course of working memory , the values of JEIs were averaged for 10 experiments in 6 rats . The results showed that the normalized JEIs value was 0.408 鹵 0.040 ( mean 鹵 standard error ) within 3s of the reference point of working memory , and the maximum value of 1s in the reference point of working memory was 0.696 鹵 0.040 ( mean 鹵 standard error ) , and the difference between them was statistically significant .

3 ) Co - coding of the 緯H component of Spikes - LFPs on working memory

The results showed that the normalized JEIs values were 0.393 鹵 0.041 ( mean 鹵 standard error ) within 3s of the reference point of working memory and 0.690 鹵 0.038 ( mean 鹵 standard error ) of 1s before the reference point of working memory , and the difference between them was statistically significant .

Conclusions of the study

( 1 ) In the process of working memory , the energy of LFPs is significantly increased , which is the main frequency component of working memory .

( 2 ) The theta and low frequency gamma - component modulation intensity of LFPs in rat frontal cortex were significantly enhanced in the correct task of behavioral learning in rats . Both of them co - encoded the working memory .

( 3 ) The theta and Y components of the frontal lobe cortex and LFPs of the rats co - encoded the working memory . In the correct experiment of rat behavior , the synergistic activity of the related components ( 0 , low frequency gamma and high frequency gamma ) of 6 rats in the frontal cortex and LFPs was significantly enhanced and reached the peak before the reference point of the working memory .
【學位授予單位】：天津醫(yī)科大學
【學位級別】：博士
【學位授予年份】：2014
【分類號】：R318.04

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本文編號：1982648