Neurophysiology of Breathing in Mammals

Abstract

The sections in this article are: 1 Respiratory Homeostasis and Control of Respiratory Movements 1.1 Effectors of Ventilation 1.1.1 Respiratory Movements 1.1.2 Respiratory Motoneuronal Outflow 1.2 Respiratory Muscles and Their Innervation 1.2.1 Diaphragm and Phrenic Motoneurons 1.2.2 Intercostal Muscles and Motoneurons 1.2.3 Laryngeal and Pharyngeal Muscles and Motoneurons 1.2.4 High-Frequency Oscillations 1.3 Summary 2 Central Location of Respiratory Controller 2.1 Historical Background 2.1.1 Stimulation 2.1.2 Anatomy 2.1.3 Neuron Recording 2.2 Summary 2.3 Modern View 2.3.1 Spinal Cord Genesis of Respiratory Movements? 2.3.2 Brain Stem Respiratory Neurons 2.4 Brain Stem Anatomy 2.4.1 Medulla 2.5 Classification of Respiratory Neurons 2.5.1 Patterns of Respiratory Neuron Discharge 2.6 Connections Between Respiratory Neurons 2.6.1 Intramedullary Connections 2.6.2 Ventral Surface Connections 2.6.3 Pontomedullary Connections 2.6.4 Bulbospinal Connections 2.6.5 Importance of Connections Between Hemi-Medullae 2.7 Location and Mechanisms for Generation of Respiratory Patterns 2.8 Production of Respiratory Pattern 2.8.1 Pontine Respiratory Group 2.8.2 Dorsal and Ventral Respiratory Groups 2.9 Central Pattern Generation and Respiration 2.9.1 Mechanisms for Rhythmogenesis 2.9.2 Perturbations and Network Models for Respiratory Pattern Generation 2.9.3 Interactions Among Respiratory Neurons 2.9.4 Mechanisms Underlying Generation of Augmenting Inspiratory and Expiratory Activity 2.9.5 Generation of Phase Transitions 2.9.6 Possible Mechanisms Underlying Phase Transitions 2.9.7 Summary 2.10 Hypothesis for Role of Dorsal and Ventral Respiratory Groups in Generating Respiratory Pattern 3 Sensors 3.1 Time Course of Responses to Respiratory Afferent Stimulation 3.2 Integrated Responses to Changes in Carbon Dioxide 3.2.1 Intracranial Carbon Dioxide Reception—Phenomenology of Ventral Surface 3.2.2 Critique 3.2.3 Neuronal Response to Hyper- and Hypocapnia: A Caveat 3.2.4 Spinal Motoneurons 3.2.5 Laryngeal Motoneurons 3.2.6 Dorsal-Ventral Respiratory Group Neurons 3.2.7 Ventral Medullary Neurons 3.3 Integrated Responses to Changes in Oxygen 3.3.1 Heymans Type (Arterial) Chemoreceptors 3.3.2 Effects of Oxygen on Medullary Respiratory Neurons 3.4 Summary 4 Mechanoreceptors 4.1 Pulmonary Stretch Receptors 4.1.1 Inspiratory Shortening Reflex 4.1.2 Laryngeal Pattern 4.1.3 Responses of Brain Stem Inspiratory Neurons to Activation of Lung Stretch Receptors 4.1.4 Expiratory Facilitatory Reflex and Control of Expiratory Duration 4.1.5 Responses of Expiratory Neurons to Lung Inflations 4.2 Summary 5 Exercise—An Example of an Integrated Response 5.1 Critique 6 State Dependence 7 conclusion7 Conclusion