內容簡介
Sciences Under Space Conditions describes the interaction of gravity with neuronal systems. To deliver the basic scientific and technological background, the structures of neuronal systems are described and platforms for gravity research are presented. The book is rounded off by information about the interaction of chemical model systems with gravity and some simulations, and results about the interaction of gravity with neuronal systems from single molecules to the entire human brain are demonstrated. This is the first book to give a complete overview about neurophysiological research under conditions of variable gravity.
The book is intended for scientists in the field of space research, neurophysiology, and those who are interested in the control of non-linear systems by small external forces.
作者簡介
Dr. Meike Wiedemann and Dr. Florian P.M. Kohn are Biological Scientists in the Lab of Membranephysiology at the University of Hohenheim, Germany and have been working in the field of life sciences under space condition for some years. Prof. Harald Roesner has been working in the field of Neurophysiology and is now retired. Prof. Wolfgang R.L. Hanke is the leader of the Department of Membranephysiology at the University of Hohenheim.
內頁插圖
目錄
Chapter I Introduction
1.1 Historical remarks
1.1. Gravitational research
1.2 Excitable media and their control by small external forces
1.3 Waves and oscillations in biological systems
1.4 Book layout
References
Chapter 2 Gravity
2.1 Physical remarks
2.2 Perception of gravity by living systems
References
Chapter 3 Basic Structure of Neuronal Systems
References
Chapter 4 Platforms for Gravitational Research
4.1 Microgravity platforms
4.1.1 Short term platforms
4.1.2 Long term platforms
4.1.3 Magnetic levitation
4.2 Removing orientation
4.2.1 Clinostats
4.2.2 Random positioning machine
4.3 Macro-gravity platforms
4.3.1 Centrifuge
References
Chapter 5 A Model Systems for Gravity Research: The Belousov-Zhabotinsky Reaction
5.1 Setup for the Belousov-Zhabotinsky experiments
5.2 Preparation of gels for the Belousov-Zhabotinsky reaction
5.3 Data evaluation
References
Chapter 6 Interaction of Gravity with Molecules and
Membranes
6.1 Bilayer experiments
6.1.1 Hardware for the Microba mission
6.1.2 Hardware for the drop-tower
6.1.3 Hardware for parabolic flights
6.1.4 Hardware for laboratory centrifuge
6.1.5 Experimental results
6.2 Patch-clamp experiments
6.2.1 Principles of patch-clamp experiments
6.2.2 Hardware for the drop-tower
6.2.3 First hardware for parabolic flights
6.2.4 For the drop-tower
6.2.5 First parabolic flight experiment
6.2.6 Second hardware for parabolic flights
6.2.7 Second parabolic flight experiment
6.2.8 First results and future perspectives
References
Chapter 7 Behavior of Action Potentials Under Variable Gravity Conditions
7.1 Introductory remarks
7.2 Materials and methods
7.3 Isolated leech neuron experiments
7.4 Earthworm and nerve fiber experiments (rats and worms)
7.5 Discussion
References
Chapter 8 Fluorescence and Light Scatter Experiments to Investigate Cell Properues at Microgravity
8.1 Fluorescence measurements to determine calcium influx and membrane potential changes
8.1.1 Intracellular calcium concentration experiments
8.1.2 Membrane potential experiments
8.2 Light scatter experiments to determine changes in cell size
8.2.1 Static light scatter
8.2.2 Dynamic light scatter
References
Chapter 9 Spreading Depression: A Self-organized Excitation Depression Wave in Different Gravity Conditions
9.1 The retinal spreading depression
9.2 Gravity platforms used for retinal spreading depression experiments
9.2.1 Methods Contents
9.2.2 Experiment setup and protocol for spreading depression experiments in parabolic flights
9.2.3 Experiment setup and protocol for spreading depression experiments on TEXUS sounding rocket
9.2.4 Setup and protocol for spreading depression experiments in the centrifuge
9.2.5 Data analysis
9.3 Results
9.3.1 Spreading depression experiments in parabolic flights and in the centrifuge
9.3.2 Spreading depression experiments on sounding rockets and in the centrifuge
9.3.3 Determination of latency of spreading depression waves in the centrifuge
9.3.4 Summary of all spreading depression experiments on different gravity platforms
9.4 Discussion
9.4.1 Comment on different gravity platforms
References
Chapter 10 The Brain Itself in Zero-g
10.1 Methods
10.1.1 Slow cortical potentials (SCP)
10.1.2 Classical frequency bands in EEG
10.1.3 Peripheral psycho physiological parameters
10.1.4 Protocol and data analysis
10.1.5 Subjects
10.1.6 Ethic
10.2 Results
10.2.1 Slow Cortical Potentials (SCP)
10.2.2 Frequency band EEG
10.2.3 Peripheral stress parameters
10.3 Discussion
10.3.1 Slow cortical potentials
10.3.2 Frequency band EEG
10.3.3 Peripheral parameters
10.4 Conclusion
References
Chapter 11 Effects of Altered Gravity on the Actin and Mierotubule Cytoskeleton, Cell Migration and Neurite Outgrowth
11.1 Summary
11.2 Introductory remarks
11.3 Material and methods
11.3.1 Cell transfection
11.3.2 Cell culture and experiments with SH-SY5Y neuroblastoma cells
11.3.3 Cell migration experiments- Human carcinoma cell lines
11.3.4 Scratch Migration Assay (SMA)
11.3.5 Neurite outgrowth experiments-Primary cell culture of embryonic chicken spinal cord neurons
11.3.6 Imunostaining of cells
11.3.7 Staining of F-actin
11.3.8 Microscopy and live imaging
11.4 Results and discussion
11.4.1 Effects of altered gravity on actin-driven lamellar protrusion of SH-SY5Y neuroblastoma cells
11.4.2 Effect of altered gravity on the microtubule cytoskeleton of SH-SY5Y neuroblastoma cells
11.4.3 Effects of altered gravity on cell migration
11.4.4 Effects of altered gravity on the intensity and direction of neurite outgrowth
References
Chapter 12 Discussion and Perspectives
References
Index
精彩書摘
The question, which can be the cellular and further consequences of a higher open state probability is not that simple to be answered and will depend on the ion-channel under investigation. Up to now, only data for some specialized cases (model systems) are available, which are not to be applied to neuronal systems. However, let us speculate about the membrane of a neuron, having at least potassium channels to give the resting membrane potential and sodium channel to en- able action potentials (Hille, 1992; Weiss, 1997). The sodium channels are closed at rest; the potassium channels are permanently open at a non-zero open state probability. In a simplified discussion, closed sodium-channels would not be affected by gravity as the gating mechanism is of electrical nature, a depolarization of membrane across a threshold value. However, potassium channels as being open anyhow, would react to gravity changes, applying microgravity would lower their open state probability. Having the Goldman equation in mind (Weiss, 1997) this would lead to a membrane depolarization. As long as the threshold for sodium channels is not reached, no action potentials would be elicited, but further stimulation would more easily give an action potential.
The next set of experiments which has to be taken into account then is those with spontaneously spiking neurons. A prediction from the above statements (speculations) would be that in this case the spike frequency should be higher at microgravity. Just that has been shown. Also, a direct measurement of membrane potential should result in less negative values. In the experiments utilizing voltage sensitive dyes accurately this has been shown. According to textbook knowledge (Hille, 1992), at depolarization of membrane potential, voltage sensitive calcium channels open in the cell membrane, calcium enters the cell, and the intracellular calcium concentration increases. This could not be verified, in some experiments instead it was shown that the intracellular calcium level at microgravity drops (see above). As the intracellular calcium concentration is a highly regulated value, this could be due to secondary effects, but will have again to be investigated more deeply.
復雜係統的自發秩序與結構演化:跨尺度視角下的動力學機製 本書概要 本書深入探討瞭復雜係統中自組織現象與斑圖形成的普適性動力學原理,並著重考察瞭這些現象在不同空間和時間尺度上如何湧現與演化。我們聚焦於如何從基本的相互作用單元齣發,理解宏觀結構和有序狀態的形成過程,而非局限於單一學科的具體模型。全書構建瞭一個跨越物理學、化學、生物學和信息科學的統一理論框架,用以描述和預測復雜係統在非平衡態下的行為模式。 第一部分:復雜係統動力學的基本概念與熱力學基礎 本部分奠定瞭理解自組織現象的理論基石。首先,我們從統計力學的角度審視瞭開放係統與耗散係統中的熱力學性質。不同於平衡態下的熵增定律,本書詳細闡述瞭遠離平衡態的結構如何通過能量和物質的持續交換來維持其低熵狀態,即“耗散結構”的形成條件。 我們詳細分析瞭控製復雜係統行為的非綫性動力學方程。從洛倫茲吸引子到更普遍的遲滯現象,非綫性項如何導緻係統對初始條件的敏感依賴性(混沌)和確定性行為中的隨機性。通過深入研究分岔理論,我們揭示瞭係統參數微小變化如何引發拓撲結構上的突變,從而導緻新的宏觀有序狀態的齣現。特彆地,我們引入瞭“臨界現象”的概念,探討瞭係統在相變點附近,漲落如何被放大並主導宏觀尺度的集體行為。 第二部分:空間結構與時間周期性的湧現 本部分的核心在於分析空間和時間維度上的有序模式是如何在無序背景中自發産生的。我們從反應-擴散係統入手,這是描述斑圖形成問題的經典模型。詳細解析瞭圖靈機製(Turing mechanism)的數學基礎,即通過具有不同擴散速率和相互作用強度的組分之間的負反饋環路,實現穩定空間結構的形成。我們不僅重述瞭經典的反應-擴散模型,更拓展到具有非局部相互作用和時滯效應的變種,探討它們如何生成更復雜、非周期的空間構型,如螺鏇波、行波解和蜂窩狀結構。 在時間動力學方麵,本書重點研究瞭振蕩與同步現象。我們分析瞭具有內在周期性的單元如何通過相互耦閤,從隨機振蕩過渡到高度相乾的集體節律。這包括對化學振蕩器(如Belousov-Zhabotinsky反應)的動力學分析,以及在耦閤振蕩網絡中如何形成相位鎖定和波動的傳播。我們還討論瞭時空斑圖——例如行進波和鏇轉激發波——的穩定性、速度以及它們在限製性幾何結構(如彎麯錶麵或管道)中的傳播特性。 第三部分:信息、尺度與層次結構 復雜係統的顯著特徵之一是信息在不同層次間的編碼和傳遞。本部分將視角提升到信息論和網絡科學的層麵。我們采用圖論工具來描述係統中的相互作用網絡,探討網絡的拓撲結構(如無標度網絡、小世界網絡)如何影響信息的全局傳播效率和魯棒性。 我們深入研究瞭“湧現”(Emergence)的本質。湧現性指係統整體行為無法從其單個組成部分的簡單疊加中預測。本書通過信息壓縮和有效場論的方法,嘗試量化不同尺度間信息流的損失與重構,旨在建立描述從微觀動力學到宏觀集體行為的規範轉化規則。我們還考察瞭“尺度不變性”和“重整化群”的思想在描述跨尺度現象中的應用,強調瞭某些動力學規律在不同放大倍數下保持不變的內在原因。 第四部分:跨學科應用與新挑戰 在最後一部分,我們將理論框架應用於幾個關鍵的跨學科領域,展示自組織和斑圖動力學的普遍性。 在材料科學中,我們討論瞭液態晶體、自組裝分子結構以及在外部場作用下形成周期性納米結構的案例,重點分析瞭界麵能和邊界條件對最終宏觀形貌的決定作用。 在流體力學中,我們探討瞭湍流的起源和結構。湍流被視為一種高度復雜的、多尺度的耗散結構,我們使用渦鏇理論和統計矩分析來描述其能量級聯過程。 在生態學和模式形成領域,本書分析瞭種群分布的斑圖形成,例如動物皮毛上的斑點和條紋圖案,以及生態係統中物種的空間隔離現象,將其歸因於不同物種間的競爭擴散平衡。 本書最後提齣當前研究麵臨的前沿挑戰,包括如何有效地模擬和控製高維、高非綫性的復雜係統,以及在涉及復雜反饋和學習機製的係統中,如何從動力學角度理解自適應和演化過程。我們的目標是為讀者提供一個強健的、跨越學科界限的工具箱,用於分析和理解自然界中普遍存在的自發秩序之美。