Electrophoretic analysis of multiple forms of rat cardiac myosin: Effects of hypophysectomy and thyroxine replacement

Section I-Peripheral Nerve.- 1 Peripheral Nerve Structure.- 1. Introduction.- 2. Histology and Development.- 3. The Axon.- 3.1. Filaments and Microtubules.- 3.2. Other Organelles and the Axolemma.- 4. Sheaths of Axons.- 4.1. Schwann Cells.- 4.2. Myelin.- 4.3. Function of Schwann Cells and Their Myelin Sheaths.- 4.4. Connective Tissue Sheaths.- 5. References.- 2 The Nerve Impulse.- 1. Introduction.- 2. Passive Electrical Properties.- 3. Voltage-Clamp Analysis of the Ionic Current.- 4. Momentary Current-Voltage Relations.- 5. The Threshold Conditions for Excitation.- 6. Factors Determining Conduction Velocity.- 7. References.- 3 Axoplasmic Transport-Energy Metabolism and Mechanism.- 1. Introduction.- 2. Fast Axoplasmic Transport.- 2.1. Characterization.- 2.2. Mechanism and Energy Supply.- 2.3. Transport and Membrane Function.- 3. Slow Axoplasmic Transport.- 3.1. Characterization.- 3.2. Mechanism.- 4. References.- Section IIA-Junctional Transmission-Structure.- 4 Neuromuscular Junctions and Electric Organs.- 1. Introduction.- 2. The Typical Neuromuscular Junction.- 2.1. Distribution and Location of Nerve Terminals.- 2.2. The Axon.- 2.3. The Synaptic Space.- 2.4. Postjunctional Muscle Fiber.- 3. Variations of Motor End Plates.- 3.1. Variations from Class to Class.- 3.2. Endings on Slow-Twitch and Rapid-Twitch Fibers.- 3.3. Endings on Slow Tonic Muscle Fibers.- 4. Electric Organs.- 4.1. Electrocytes.- 4.2. Innervation and Ultrastructure.- 5. References.- 5 The Peripheral Autonomic System.- 1. Anatomical Considerations: Sympathetic and Parasympathetic Divisions.- 2. Morphological Observations.- 2.1. Preganglionic Neurons.- 2.2. Postganglionic Neurons.- 2.3. Adrenal and Extra-Adrenal Chromaffin Cells.- 3. References.- 6 Ultrastructure of Ganglionic Junctions.- 1. General Considerations.- 2. Sympathetic Ganglia.- 2.1. Amphibia.- 2.2. Reptiles.- 2.3. Mammals.- 2.4. Some Effects of Different Fixatives.- 3. Parasympathetic Ganglia.- 3.1. Ciliary Ganglion.- 3.2. Otic Ganglion.- 3.3. Ganglia of the Enteric Plexuses.- 3.4. Cardiac Ganglion Cells.- 4. Summary and Comment.- 5. References.- Section IIB-Junctional Transmission-Function.- 7(i) Neuromuscular Transmission-Presynaptic Factors.- 1. Synthesis, Storage, and Release of Acetylcholine.- 1.1. Synthesis of ACh.- 1.2. Storage and Release.- 2. The Acceleration of Release by Nerve Impulses.- 2.1. The Role of the Nerve Impulse.- 2.2. The Role of Ca2+.- 2.3. After- Effects of Depolarization-Secretion Coupling.- 3. References.- 7 (ii) Neuromuscular Transmission-The Transmitter-Receptor Combination.- 1. Introduction.- 2. Molecular Basis of Chemoelectric Transduction.- 3. Pharmacology.- 4. Chemical Nature of the Acetylcholine Receptor.- 5. Desensitization.- 6. References.- 7 (iii) Neuromuscular Transmission-Enzymatic Destruction of Acetylcholine.- 1. Location and Measurement of Cholinesterases at the Junction.- 1.1. Histochemical Staining.- 1.2. Microchemical Methods.- 1.3. Assay of External AChE.- 1.4. Radioautographic Methods.- 2. Amounts and Types of Cholinesterase at the Junctions.- 3. Requirement for AChE in Impulse Transmission.- 4. Relation of AChE to ACh- Receptors.- 5. Quantitative Relation of AChE to ACh at the End Plate.- 6. References.- 8 Ganglionic Transmission.- 1. Introduction.- 2. Response of Autonomic Ganglia to Preganglionic Volleys.- 2.1. Response of Normal Ganglia.- 2.2. Response of Curarized Ganglia.- 2.3. Slow Ganglionic Responses and Afterdischarges.- 3. Electrical Constants of Ganglion Cell Membrane.- 4. Action Potentials of Single Ganglion Cells.- 4.1. Response to Antidromic Stimulation.- 4.2. Response to Direct Intracellular Stimulation.- 4.3. Response to Orthodromic Stimulation.- 4.4. Ionic Requirement for Generation of Action Potential.- 5. Nature and Electrogenesis of Postsynaptic Potentials.- 5.1. The "Fast" Excitatory Postsynaptic Potential.- 5.2. The "Slow" Excitatory Postsynaptic Potential.- 5.3. The "Late Slow" Excitatory Postsynaptic Potential.- 5.4. The "Slow" Inhibitory Postsynaptic Potential.- 6. Cholinergic and Adrenergic Receptors at Preganglionic Nerve Terminals.- 6.1. Cholinergic Receptor Site.- 6.2. Adrenergic Receptor Site.- 7. References.- 9 Function of Autonomic Ganglia.- 1. Introduction.- 2. Ganglia as Coordinating Centers.- 2.1. The Relay Hypothesis of Ganglionic Function.- 2.2. Development of a Stochastic Hypothesis.- 3. Experimental Evidence.- 3.1. Observed Patterns of Innervation.- 3.2. Ganglionic Activity and Factors Influencing It.- 3.3. Relative Autonomy of Ganglia.- 4. Conclusions.- 5. References.- 10 Peripheral Autonomic Transmission.- 1. Introduction.- 2. Definition of the Autonomic Neuromuscular Junction.- 2.1. Relation of Nerve Fibers to Muscle Effector Bundles.- 2.2. Relation of Nerve Fibers to Individual Smooth Muscle Cells.- 3. Adrenergic Transmission.- 3.1. Introduction.- 3.2. Structure of Adrenergic Neurons and Storage of Noradrenaline.- 3.3. Electrophysiology of Adrenergic Transmission.- 3.4. Ionic Basis of the Action of Catecholamines on the Postjunctional Membrane.- 3.5. Summary.- 4. Cholinergic Transmission.- 4.1. Introduction.- 4.2. Localization of Acetylcholinesterase.- 4.3. Electrophysiology of Cholinergic Transmission.- 4.4. Ionic Basis of the Action of ACh on the Postjunctional Membrane.- 4.5. Summary.- 5. Purinergic Transmission.- 5.1. Introduction.- 5.2. Electrophysiology of Purinergic Transmission.- 5.3. Summary.- 6. Conclusions.- 7. References.- 11 "Trophic" Functions.- 1. Introduction.- 2. Regulation of Taste Buds.- 3. Regulation of Amphibian Limb Regeneration.- 4. Regulation of Physiological and Metabolic Properties of Muscle.- 4.1. Resting Membrane Potential.- 4.2. Acetylcholine Sensitivity.- 4.3. Cholinesterase Activity.- 4.4. The Role of ACh Release.- 4.5. The Dynamic Nature of the Muscle Fiber.- 4.6. Plasticity of the Motor Unit.- 5. Mechanisms of Neural Regulation.- 6. References.- Section III-Receptors-Structure and Function.- 12 Cutaneous Receptors.- 1. Introduction.- 2. Morphology of Cutaneous Nerves.- 2.1. Uniformity of Cutaneous Axons.- 2.2. Relative Numbers of Myelinated and Nonmyelinated Axons.- 3. Morphology of Cutaneous Receptors.- 3.1. Encapsulated Receptors.- 3.2. Unencapsulated Corpuscular Receptors.- 3.3. Noncorpuscular Receptors.- 4. Physiology of Cutaneous Receptors.- 4.1. Cutaneous Mechanoreceptors.- 4.2. Cutaneous Thermoreceptors.- 4.3. Nociceptors.- 5. References.- 13 The Pacinian Corpuscle.- 1. Introduction.- 2. Morphology.- 3. Afferent Responses to Mechanical Stimuli.- 4. Mechanical Properties of the Corpuscle.- 5. Receptor Potentials.- 6. Impulse Activity in the Nerve Terminal.- 7. Distribution of Pacinian Corpuscles.- 8. Central Effects of Impulses from Pacinian Corpuscles.- 9. References.- 14 Receptors in Muscles and Joints.- 1. Introduction.- 2. Joint Receptors.- 3. Tendon Organs.- 4. Muscle Spindles.- 4.1. Reptiles.- 4.2. Amphibia.- 4.3. Birds.- 4.4. Mammals.- 5. Uncertain Origin of Adaptation.- 6. References.- 15 Enteroceptors.- 1. Introduction.- 2. Methods.- 2.1. Histology.- 2.2. Physiology.- 3. Cardiovascular Receptors.- 3.1. Systemic Arterial Baroreceptors.- 3.2. Pulmonary Arterial Baroreceptors.- 3.3. Ventricular Receptors.- 3.4. Atriovenous Receptors.- 4. Respiratory System Receptors.- 4.1. Cough and Irritant Receptors.- 4.2. Pulmonary Stretch Receptors.- 4.3. Type J Receptors.- 4.4. Other Receptors.- 5. Alimentary System Receptors.- 5.1. Muscular Receptors.- 5.2. Serosal Receptors.- 5.3. Muscularis Mucosae Receptors.- 5.4. Chemoreceptors.- 5.5 Hepatic Osmoreceptors.- 6. Urinary Tract Receptors.- 6.1. Bladder.- 6.2. Urethra.- 7. Other Enteroreceptors.- 8. References.- 16 Arterial Chemoreceptors.- 1. Introduction.- 2. Structure.- 2.1. Light Microscopy.- 2.2. Electron Microscopy.- 2.3. Degeneration Studies.- 3. Function.- 3.1. Types of Activity in the Nerve Supply to the Receptor Complex.- 3.2. The Type I Cell.- 4. The Identity of the Receptor.- 4.1. The Received View.- 4.2. A New Hypothesis.- 5. References.- 17 Taste Receptors.- 1. Introduction.- 2. Gustatory Nerve Fiber Response to Chemical Stimuli.- 2.1. Multiple Sensitivity of Single Chorda Tympani Fibers.- 2.2. Neural Code for Quality of Taste and "Across-Fiber Pattern" Theory.- 3. Electrical Responses of Gustatory Cells to Chemical Stimuli.- 3.1. Innervation and Structure of Taste Bud.- 3.2. How Do Gustatory Cells Respond to Chemical Stimuli?.- 4. References.

The Peripheral Nervous System

Mismatches between neurotransmitter and receptor localizations in brain: observations and implications.

Serotonin nerve terminals in adult rat neocortex

The monoamine innervation of rat cerebral cortex: Synaptic and nonsynaptic axon terminals

An electron microscope study of the innervation of smooth muscle of the guinea pig vas deferens was undertaken in order to find a structural basis for recent electrophysiological observations. The external longitudinal muscle coat was examined in transverse section. Large areas of the surfaces of adjacent muscle cells were 500 to 800 A apart. Closer contacts were rare. A special type of close contact suggested cytoplasmic transfer between neighbouring cells. Groups of non-myelinated axons from ganglia at the distal end of the hypogastric nerve ramified throughout the muscle. Some small axon bundles and single axons lay in narrow fissures within closely packed muscle masses. Many axons contained "synaptic vesicles." About 25 per cent of the muscle fibres in the plane of section were within 0.25 µ of a partly naked axon; of these 15 per cent were within 500 A of the axon, and about 1 per cent made close contact (200 A) with a naked axon. It is unlikely that every muscle fibre is in close contact with an axon, and it is not possible for every fibre to have many such contacts. Muscle fibres are probably activated by both diffusion of transmitter from naked portions of axons a fraction of a micron distant, and electrotonic spread of activity from neighbouring cells.

/pdf/correlation-of-fine-structure-and-physiology-of-the-4k8xtcelc4.pdf

Correlation of fine structure and physiology of the innervation of smooth muscle in the guinea pig vas deferens.

Smooth muscle cells of the external longitudinal coat of the guinea pig vas deferens were followed for 480 µ at 4.5-µ intervals. Muscle bundles and fibers interwove, facilitating intermuscular and neuromuscular contacts. The ribbon- or rodlike muscle cells were about 450 µ long, 3,000 µ3 in volume, and 4,500 µ2 in area. The thickened nuclear zone lay anywhere along the middle one-third of the cell. Intercellular distances were 500–800 A. Intrusions were rare, and tight-junctions absent. At any level in a field of 80 muscle fibers there were 10–15 nerve bundles, each containing several varicose axons. Bundles and axons divided. Axons, en passage, were frequently within 500–1,000 A of a muscle fiber. En passage close contacts were rate. Axon terminations were bare, and bare axons invariably terminated. Bare terminations had scattered vesicle-laden varicosities and were from 10µ-60 µ in length, and all ended within 500 A of muscle fibers. Some made close contact with muscle fibers. Less than half of the muscle cells received this close contact, but some cells were approached by more than one termination. Most terminations involved more than one cell. Some cells had little or no innervation. Some groups of cells had a rich innervation. There was very little evidence of sensory innervation. These conclusions are not valid for other smooth muscles.

https://rupress.org/jcb/article-pdf/37/3/794/1384503/794.pdf

The nervous environment of individual smooth muscle cells of the guinea pig vas deferens

Fine structure, enzyme activity, and transmembrane potentials of normal and glycerinated ventricular muscle of the toad were studied. For electron microscopy, osmium tetroxide and Araldite were used. Plasma membranes are firmly attached to Z bands. Both the T system and sarcoplasmic reticulum are poorly developed. Small bodies of medium density may be lysosomes derived from the Golgi zone. Denser bodies may be catecholamine granules. Fine tubules of unknown significance, about 200 A in diameter and of considerable length, lie in conspicuous, although infrequent bundles. Glycogen and mitochondria are abundant. After weeks of extraction in 50 per cent buffered glycerol, most organelles were still present, and much of the gross damage was probably due to osmotic destruction of membranes weakened by extraction. Many mitochondria were well preserved. Plasma and nuclear membranes had diffuse outlines and tended to be broken. Considerable activity remained of the enzymes succinic dehydrogenase, cytochrome oxidase, and phosphorylase after the extraction, but decreased with prolonged soaking. The normal transmembrane potential was about 95 mv; in extracted muscle after 6 weeks it was about 35 mv. The view that glycerinated muscle is a simple system of actin and myosin is clearly wrong. The activity of other organelles still present must affect the actions of many drugs and ions experimentally added.

/pdf/some-observations-on-the-fine-structure-and-metabolic-4jkoo467u3.pdf

Some observations on the fine structure and metabolic activity of normal and glycerinated ventricular muscle of toad.

Microsomes prepared from heart muscle of hyperthyroid dogs accumulate and exchange calcium more readily than do microsomes isolated from euthyroid heart muscle. The activity of the calcium-activated ATPase enzyme and cardiac stores of high energy phosphates and catecholamines are not influenced by the hyperthyroid state. Electron micrographs prepared from perfusion-fixed heart muscle failed to show evidence of an altered mitochondrial morphology associated with the hyperthyroid state.

Neil C. R. Merrillees

Papers

Correlation of fine structure and physiology of the innervation of smooth muscle in the guinea pig vas deferens.

The nervous environment of individual smooth muscle cells of the guinea pig vas deferens

Some observations on the fine structure and metabolic activity of normal and glycerinated ventricular muscle of toad.

Influence of hyperthyroidism on the uptake and binding of calcium by cardiac microsomal fractions and on mitochondrial structure

Species-determined differences in cardiac phosphorylase activity.