Relief of dental pain by ice massage of the hand.

Patients suffering from acute dental pain were treated with ice massage of the web between the thumb and index finger of the hand on the same side as the painful region. Control groups received tactile massage alone or with explicit suggestion that the massage was intended to alleviate their pain. Changes in pain intensity produced by the procedures were measured with the McGill Pain Questionnaire. Ice massage decreased the intensity of the dental pain by 50% or more in the majority of patients. Furthermore, the pain reductions produced by ice massage were significantly larger than those produced by tactile massage alone or with explicit suggestion. The results indicate that ice massage has pain-reducing effects comparable to those of transcutaneous electrical stimulation and acupuncture. The fact that cold signals are transmitted to the spinal cord exclusively by A-delta fibres and not by C fibres provides a potential method for differentiating the various feedback systems that mediate analgesia produced by different forms of intense sensory input. Ice massage provides a simple method for the palliative control of pain in dental clinics.     

Cyclic AMP content of autonomic ganglia as affected by catecholamines

The relative content of cAMP was measured in the rat ganglion nodosum, lumbar ganglia of the sympathetic trunk, the main pelvic ganglion and intramural ganglia of the heart. It was observed that the basal level of cAMP in the cardiac ganglia was lower than in other ganglia. The process of stimulation of the cAMP content by noradrenaline was most pronounced in the main pelvic and lumbar ganglia, that by dopamine in the cardiac ganglia. The catecholamines failed to alter the cAMP content in the ganglion nodosum.     

Structure of peripheral synapses: autonomic ganglia

Final motor neurons in sympathetic and parasympathetic ganglia receive synaptic inputs from preganglionic neurons. Quantitative ultrastructural analyses have shown that the spatial distribution of these synapses is mostly sparse and random. Typically, only about 1%-2% of the neuronal surface is covered with synapses, with the rest of the neuronal surface being closely enclosed by Schwann cell processes. The number of synaptic inputs is correlated with the dendritic complexity of the target neuron, and the total number of synaptic contacts is related to the surface area of the post-synaptic neuron. Overall, most neurons receive fewer than 150 synaptic contacts, with individual preganglionic inputs providing between 10 and 50 synaptic contacts. This variation is probably one determinant of synaptic strength in autonomic ganglia. Many neurons in prevertebral sympathetic ganglia receive additional convergent synaptic inputs from intestinofugal neurons located in the enteric plexuses. The neurons support these additional inputs via larger dendritic arborisations together with a higher overall synaptic density. There is considerable neurochemical heterogeneity in presynaptic boutons. Some synapses apparently lack most of the proteins normally required for fast transmitter release and probably do not take part in conventional ganglionic transmission. Furthermore, most preganglionic boutons in the ganglionic neuropil do not form direct synaptic contacts with any neurons. Nevertheless, these boutons may well contribute to slow transmission processes that need not require conventional synaptic structures.     

Action of a beta-bungarotoxin on autonomic ganglia and adrenergic neurotransmission.

A beta-bungarotoxin was isolated from the venom of Bungarus multicinctus by column chromatography on Sephadex G-50 and SP-Sephadex. The toxin produced presynaptic effects on neuromuscular transmission with characteristics similar to those described by others. In a sympathetic ganglion, the toxin increased spontaneous acetylcholine (ACh) release and decreased ACh release evoked by preganglionic nerve stimulation. The toxin did not block the response of isolated ileum to cholinergic nerve stimulation, did not block the release of noradrenaline from the adrenergic nerve terminals of a nictitating membrane preparation, and did not alter the responses of smooth and cardiac muscle preparations to noradrenaline. It is suggested that the specificity of beta-bungarotoxin for certain nerve terminals is related either to selective binding of the toxin or to the selective presence of a necessary substrate for its action. An attempt to show selective binding of 125I-toxin to cholinergic nerve terminals in skeletal muscle was not successful.     

Basal ganglia and functions of the autonomic nervous system

1. The aim of this mini-review was to describe an underrecognized but important aspect of the basal ganglia diseases, the dysfunction of the autonomic nervous system that patients suffer owing to the degenerative process affecting these structures, mainly Parkinson's disease.2. We analyze the most prevalent autonomic abnormalities in these patients from an experimental and clinical point of view.     

Immunohistochemical characterisation of pelvic autonomic ganglia in male mice

Pelvic ganglia are mixed sympathetic-parasympathetic ganglia and provide the majority of the autonomic innervation to the urogenital organs. Here we describe the structural and histochemical features of the major pelvic ganglion in the male mouse and compare two different mouse strains. The basic structural features of the ganglion are similar to those in the male rat. Almost all pelvic ganglion cells are monopolar and most are cholinergic. All contain either neuropeptide Y (NPY) or vasoactive intestinal peptide (VIP), or both peptides together. The peptide coexistence varies between strains, with C57BL/6 mice having similar proportions of neurons with NPY alone, VIP alone or both peptides. In contrast, virtually all pelvic neurons in the Quackenbush-Swiss (QS) strain express NPY, i.e. the level of VIP/NPY coexistence is much higher. Cholinergic axons provide the major nerve supply to epithelia of reproductive organs, bladder smooth muscle and, as described previously, penile erectile tissue. They also provide a minor component of the smooth muscle innervation of the prostate gland, seminal vesicles and vas deferens. Virtually all non-cholinergic pelvic ganglion cells are noradrenergic and contain NPY. Their major target is smooth muscle of reproductive organs. This study shows that the male mouse pelvic ganglion bears many similarities to that in the rat, but that VIP/NPY colocalisation is much more common in the mouse. We also show that there are differences in peptide expression in parasympathetic pelvic neurons between strains of mice. These studies provide the framework for future investigations on neural regulation of urogenital function, particularly in transgenic and knockout models.     

Synaptic transmission in thoracic autonomic ganglia of the dog

Afferent stimulation of one canine thoracic cardiopulmonary nerve can generate compound action potentials in another ipsilateral cardiopulmonary nerve. These compound action potentials persist after acute decentralization of the middle cervical ganglion, indicating that they result from neural activity in the middle cervical ganglion and thoracic nerves. Changing the frequency of stimulation can alter the compound action potentials, suggesting that temporal facilitation or inhibition occurs in this middle cervical ganglion preparation. The compound action potentials can be modified by stimulation of sympathetic preganglionic fibers and by hexamethonium, atropine, phentolamine, propranolol, and (or) manganese. It thus appears that afferent cardiopulmonary nerves can activate efferent cardiopulmonary nerves via synaptic mechanisms in the stellate and middle cervical ganglia. It also appears that these mechanisms involve adrenergic and cholinergic receptors and are influenced by preganglionic sympathetic fibers arising from the cord.