The Subthalamic Nucleus (eBook)

List of Contents 6
Abstract 8
Abbreviations 9
1 Introduction 15
2 The Basal Ganglia 15
2.1 Pathways Within the Basal Ganglia 16
2.1.1 Direct Pathway 16
2.1.2 Indirect Pathway 16
2.1.3 Hyperdirect Pathway 18
2.1.4 Roleof the Direct, Indirect, and Hyperdirect Pathways 18
2.1.5 Roleof Dopamine in the Direct and Indirect Pathways 20
2.1.6 Conduction Times of Pathways 20
2.2 Parkinson's Disease 20
2.2.1 Direct and Indirect Pathways in PD 21
2.2.2 Changes in Neuronal Firing Rate in PD 22
2.2.3 Changes in Neuronal Firing Pattern in PD 23
2.3 Deep Brain Stimulation 23
2.3.1 Which Neuronal Elements Are Influenced by DBS? 25
2.3.2 Mechanisms of DBS: Hypotheses 25
3 STN Activity Recorded in Vitro: Brain Slices 28
3.1 Spontaneous Activity 29
3.1.1 Single-Spike Mode 29
3.1.2 Burst-Firing Mode 31
3.2 Depolarizing and Hyperpolarizing Inputs 33
3.2.1 Plateau Potential 35
3.2.2 Low-Threshold Spike 36
3.3 Ionic Mechanisms of a Plateau Potential 37
3.4 Synaptic Inputs 39
3.5 High-Frequency Stimulation of STN Cells 40
3.6 Intrinsic Versus Extrinsic Properties: Bursts 41
3.6.1 Definition of Bursts 41
3.6.2 Burst Detection Algorithms 42
3.6.3 Network Bursts Using Burst and Phase Profiles 44
4 STN Activity Recorded in Vitro: Dissociated Cell Cultures 45
4.1 Experimental Set-up 45
4.1.1 Cell Culture 47
4.1.2 Measurement Set-up 47
4.2 Spontaneous Activity 47
4.3 Addition of Acetylcholine 49
4.4 Electrical Stimulation 51
5 STN Cell Models and Simulation of Neuronal Networks 54
5.1 Otsuka's Model 54
5.1.1 Membrane Dynamics 55
5.1.2 Spontaneous Activity 57
5.1.3 Plateau Potential Generation 59
5.2 Terman and Rubin's Model 66
5.2.1 Membrane Dynamics 66
5.2.2 Spontaneous Activity 67
5.2.3 Rebound Bursts 70
5.3 Comparison of the Otsuka Model with the Terman/Rubin Model 72
5.4 The Multi-compartment STN Model of Gillies and Willshaw 77
5.4.1 Membrane Dynamics 77
5.4.2 Activity Patterns 78
5.5 Intra-nuclear Network Models 80
5.6 Inter-nuclear Network Models 81
5.6.1 GPe- STN Network 81
5.6.2 GPe- STN-GPi-Thalamus Network 85
6 Comparison of Part I and Part II 89
6.1 Recurrent STN Axons 89
6.2 Inter-neurons in the STN 89
6.3 Fibre Tracts around and in the STN 89
6.4 Ca2-Receptors 90
6.5 Three-Dimensional Modelling 90
6.6 Types of Projection Neurons 90
6.7 Neurotransmitter Input Versus Receptors in the STN 91
6.8 The Pedunculopontine Nucleus 91
6.9 Nigro-subthalamic Connections 91
6.10 Another Cortico-subthalamic Loop 92
6.11 Nissl-Based Subdivision of the STN 92
References 95
Index 101