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The Journal of Urology Apr 1984The interrelationships of postganglionic axons in intrinsic neuroplexuses of the vesicourethral lissosphincter ('internal sphincter') were studied ultrastructurally in...
Ultrastructure of vesicourethral innervation. II. Postganglionic axoaxonal synapses in intrinsic innervation of the vesicourethral lissosphincter: a new structural and functional concept in micturition.
The interrelationships of postganglionic axons in intrinsic neuroplexuses of the vesicourethral lissosphincter ('internal sphincter') were studied ultrastructurally in the cat and rat of both sexes. Direct axoaxonal contracts between cholinergic and adrenergic axons were common in preterminal axon bundles and at neuroeffector junctions. Similar contacts between 2 cholinergic or 2 adrenergic axons were less frequent. Most contacts were ultrastructurally simple, but some had focal areas of very close axolemmal apposition, and some were focally specialized as bona fide chemical synaptic complexes. The axoaxonal contacts are introduced as a complex interaxonal synaptic system that chemically, and possibly also electrically, modulates neurotransmission in postganglionic axons innervating the lissosphincter, presynaptically (prejunctionally) at the infraganglionic level, especially by reciprocal cholinergic/adrenergic axonal interaction. This synaptic system is introduced as a potential, hitherto unrecognized, site of action of autonomic drugs, and as a key factor in the neural mechanism controlling continent closure of the lissosphincter during bladder filling, its opening to initiate and maintain voiding, and its closure to terminate the micturition cycle.
Topics: Animals; Autonomic Fibers, Postganglionic; Axons; Cats; Female; Male; Neuroeffector Junction; Rats; Rats, Inbred Strains; Synapses; Urethra; Urinary Bladder; Urination
PubMed: 6708203
DOI: 10.1016/s0022-5347(17)50624-2 -
Annals of Neurology Jun 1991We iontophoresed acetylcholine on the dorsum of the foot and simultaneously measured flare and sweat responses using laser Doppler and sudorometric techniques,... (Comparative Study)
Comparative Study
We iontophoresed acetylcholine on the dorsum of the foot and simultaneously measured flare and sweat responses using laser Doppler and sudorometric techniques, respectively. We compared these responses with those induced by histamine. Both acetylcholine and histamine produced dose-dependent flare, but only acetylcholine produced sweat responses. Responses to acetylcholine and histamine were blocked by hexamethonium chloride and pyrilamine maleate, respectively (p less than 0.01). We compared flare and sweat responses in 26 control subjects, 21 asymptomatic diabetic patients and 41 patients (17 diabetic, 24 nondiabetic) with pain symptoms suggestive of small fiber neuropathy and normal sensation (n = 15) or mild to moderate (n = 19) or severe (n = 7) sensory loss. No patient had trophic foot lesions. Basal skin blood flow and maximal flare responses were not significantly different among the various subgroups (Control subjects, 49 +/- 7.4; asymptomatic diabetic patients, 29 +/- 4; patients with small fiber neuropathy and normal sensation, 34 +/- 6; with neuropathy and mild to moderate sensory loss, 29 +/- 4.8; and with neuropathy and severe sensory loss, 35 +/- 5 ml/100 gm, for flare response, respectively). Flare responses lower than the lowest found in control subjects occurred in 5 of 21 asymptomatic diabetic patients, 4 of 15 patients with small fiber neuropathy and normal sensation, 5 of 19 with neuropathy and mild to moderate sensory loss, and 1 of 7 with neuropathy and severe sensory loss.(ABSTRACT TRUNCATED AT 250 WORDS)
Topics: Acetylcholine; Adult; Afferent Pathways; Autonomic Fibers, Postganglionic; Diabetic Neuropathies; Dose-Response Relationship, Drug; Female; Foot; Histamine; Humans; Iontophoresis; Male; Middle Aged; Neuralgia; Pain Measurement; Reflex, Abnormal; Sweating; Vasodilation
PubMed: 1892361
DOI: 10.1002/ana.410290604 -
Pflugers Archiv : European Journal of... Feb 19761. Discharge patterns in postganglionic neurones to muscle and to hairy skin of the hindlimb of chloralose anaesthetized cats were investigated during electrical...
Activation and inhibition of muscle and cutaneous postganglionic neurones to hindlimb during hypothalamically induced vasoconstriction and atropine-sensitive vasodilation.
1. Discharge patterns in postganglionic neurones to muscle and to hairy skin of the hindlimb of chloralose anaesthetized cats were investigated during electrical hypothalamic stimulation which induced either vasoconstriction or atropine sensitive vasodilation in the skeletal muscle. 2. Spontaneously active postganglionic neurones to muscle were activated both during hypothalamically induced vasoconstriction and active vasodilation. Stimulation of the hypothalamic vasodilator area induced mostly a sequence of activation-depression-activation in these neurones. Stimulation of cutaneous Group IV afferents elicited reflexes in these neurones; repetitive high frequency stimulation of large diameter afferents in the vago-depressor nerve produced depression of spontaneous activity followed by a post-inhibitory excitation. The characteristics of these neurones fit those that would be expected of vasoconstrictors. 3. Normally inactive postganglionic neurones to skeletal muscle could only be activated during hypothalamically induced atropine sensitive vasodilation. These neurones exhibit no reflexes on somatic stimulation. The axons of these neurones conduct faster than those of the spontaneously active postganglionic neurones. It is likely that they are cholinergic vasodilator neurones. 4. Most of the cutaneous postganglionic neurones to hairy skin were activated during stimulation of both the hypothalamic vasoconstrictor and the vasodilator areas. These neurones have the characteristics of cutaneous vasoconstrictor neurones. Part of the cutaneous not spontaneously active postganglionic neurones could neither be activated from the hypothalamus nor by somatic stimuli.
Topics: Action Potentials; Animals; Atropine; Autonomic Fibers, Postganglionic; Electric Stimulation; Hindlimb; Hypothalamus; Muscles; Neurons, Efferent; Skin; Vasomotor System
PubMed: 943766
DOI: 10.1007/BF00587287 -
The Journal of Comparative Neurology May 1979Horseradish peroxidase (HRP) was used to determine whether neurons in the rat superior cervical ganglion (SCG) are localized in regions of the ganglion as a function of...
Horseradish peroxidase (HRP) was used to determine whether neurons in the rat superior cervical ganglion (SCG) are localized in regions of the ganglion as a function of the postganglionic trunk they utilize. In separate experiments, each of the two major postganglionic trunks was cut 1-3 mm from the SCG and solid HRP was applied to the cut end proximal to the ganglion. The results demonstrated that the cell bodies of neurons whose axons project out the internal carotid nerve (ICN) were located primarily in the rostral part of the ganglion. Cell bodies of neurons whose axons project out the external carotid nerve (ECN) were located primarily in the caudal part. The total percentages of neuronc with axons in the ICN and ECN were about 35% and 45%, respectively. When HRP was applied to both these trunks, 73% of the neurons in the SCG were labeled. In the caudal portion of the ganglion, an additional group of neurons was observed whose axons project into the cervical sympathetic trunk. Control studies indicated that the neuronal labeling observed in our experiments was due to retrograde axonal transport rather than the direct uptake of HRP by neuronal cell bodies. Thus, neuronal subpopulations exist in specific regions of the rat SCG. The significance of these results to biochemical and electrophysiological studies is discussed.
Topics: Animals; Autonomic Fibers, Postganglionic; Ganglia, Autonomic; Male; Rats
PubMed: 429622
DOI: 10.1002/cne.901850211 -
Movement Disorders : Official Journal... Apr 2008Anhidrosis occurs in the majority of multiple system atrophy (MSA) patients but the underlying site of lesion is not well established. We describe three patients with...
Anhidrosis occurs in the majority of multiple system atrophy (MSA) patients but the underlying site of lesion is not well established. We describe three patients with long-standing MSA and anhidrosis diagnosed on the basis of a thermoregulatory sweating test. In biopsies of anhidrotic skin, immunofluorescence analysis disclosed a well preserved postganglionic sudomotor innervation in all three patients supporting the hypothesis of a preganglionic nerve fiber lesion underlying their anhidrosis. Postganglionic sudomotor fiber integrity was also confirmed by normal electrodermal responses in one patient, whereas such responses and microneurographically detectable skin sympathetic nerve activity were absent in the other two MSA patients, suggesting a functional inactivity of structurally intact postganglionic sympathetic skin fibers.
Topics: Aged; Autonomic Fibers, Postganglionic; Autonomic Nervous System Diseases; Humans; Hypohidrosis; Male; Middle Aged; Multiple System Atrophy; Sympathetic Fibers, Postganglionic; Sympathetic Nervous System
PubMed: 18361470
DOI: 10.1002/mds.21972 -
Journal of the Autonomic Nervous System May 1994Heart rate is regulated by the autonomic nervous system but little is known about the pattern of innervation of the pacemaker in the sinoatrial node, or the...
Heart rate is regulated by the autonomic nervous system but little is known about the pattern of innervation of the pacemaker in the sinoatrial node, or the subpopulations of nerves involved. Therefore in this study the pacemaker was located using electrophysiological methods and the pattern of innervation established by cholinesterase staining. In subsequent experiments, subpopulations of sympathetic, sensory and parasympathetic nerves were identified. Sympathetic nerves were labelled by glyoxylic acid-induced catecholamine fluorescence or an antiserum raised against tyrosine hydroxylase (TH). These experiments showed that the entire sinoatrial node was densely innervated by sympathetic axons, the majority of which were immunoreactive for neuropeptide Y (NPY). There were a few axons which were only immunoreactive for TH. Sensory nerves which were immunoreactive for both substance P (SP) and calcitonin gene-related peptide (CGRP) were also found throughout the sinoatrial node. In the absence of a selective marker for parasympathetic neurons, hearts were extrinsically denervated by placing them in organotypic culture to allow degeneration of extrinsic axons. In this way intrinsic parasympathetic neurons could be characterised. These experiments revealed several distinct populations of parasympathetic nerves which innervated only a small, discrete part of the sinoatrial node. These populations were immunoreactive for NPY, somatostatin (SOM) or vasoactive intestinal peptide (VIP) alone, or SOM combined with NPY, SOM with dynorphin B, and SOM with SP. These results highlight a remarkable difference in the pattern of innervation of the sinoatrial node by the sympathetic and parasympathetic nervous systems. Furthermore the presence of several distinct populations of autonomic cardiac neurons indicates a further complexity in neuronal regulation of heart rate.
Topics: Animals; Autonomic Nervous System; Biomarkers; Catecholamines; Cholinesterases; Female; Guinea Pigs; Male; Nerve Tissue Proteins; Neurons, Afferent; Neuropeptides; Organ Culture Techniques; Parasympathetic Fibers, Postganglionic; Sinoatrial Node; Sympathetic Fibers, Postganglionic
PubMed: 8014378
DOI: 10.1016/0165-1838(94)90179-1 -
Journal of the Autonomic Nervous System Mar 1980
Topics: Animals; Autonomic Fibers, Postganglionic; Cats; Chemoreceptor Cells; Electrophysiology; Heart; Muscles; Periodicity; Phrenic Nerve; Pressoreceptors; Respiration; Stellate Ganglion
PubMed: 7440899
DOI: 10.1016/0165-1838(80)90025-9 -
The contribution of cholinergic postganglionic neurotransmission to contractions of rabbit detrusor.The Journal of Pharmacology and... Nov 1977Field stimulation was used to elicit a contractile response in muscle strips from rabbit detrusor. The blockade of this response by tetrodotoxin (1 X 10(-7) M) ranged...
Field stimulation was used to elicit a contractile response in muscle strips from rabbit detrusor. The blockade of this response by tetrodotoxin (1 X 10(-7) M) ranged from 100% at 1 Hz to 86% at 40 Hz. At concentrations which produced strictly muscarinic antagonism (up to 4 X 10(-7) M) atropine depressed the frequency-response curve by about 42% at maximum but was much less effective at frequencies below 10 Hz. Similarly, treatment of the strips with hemicholinium-3 (5.2 X 10(-4) M) for 90 minutes in the presence of field stimulation at 60 Hz, depressed the frequency-response curve by 52% at maximum but produced less depression below 10 Hz. The hemicholinium-3-resistant response was neither depressed further by atropine (4 X 10(-7) M) nor potentiated by physostigmine (2 X 10(-6) M). Although hemicholinium-3 has antimuscarinic and anticholinesterase properties, these were found not to interfere with the tests for residual cholinergic transmission. Therefore, it was concluded that only part of the motor neurotransmission in rabbit detrusor is cholinergic. The remaining portion is predominant at frequencies below 10 Hz and is postulated to involve a chemical mediator other than acetylcholine.
Topics: Animals; Autonomic Fibers, Postganglionic; Electric Stimulation; Female; In Vitro Techniques; Muscle Contraction; Muscle, Smooth; Parasympathetic Nervous System; Parasympatholytics; Parasympathomimetics; Rabbits; Synaptic Transmission; Urinary Bladder
PubMed: 198528
DOI: No ID Found -
Experimental Brain Research 1974
Topics: Animals; Autonomic Fibers, Postganglionic; Brain; Cats; Electric Stimulation; Hair; Hot Temperature; Mechanoreceptors; Medulla Oblongata; Muscles; Neurons, Afferent; Pain; Reflex; Sensory Receptor Cells; Skin; Spinal Cord; Sympathetic Nervous System; Time Factors
PubMed: 4435065
DOI: 10.1007/BF00234387 -
Pharmacology & Therapeutics 1989A wide variety of substances, including amines and peptides, have been detected within the complex neuronal pathways of the enteric nervous system using... (Review)
Review
A wide variety of substances, including amines and peptides, have been detected within the complex neuronal pathways of the enteric nervous system using immunohistochemical techniques. In this article we have discussed some of the more recent data on the effects of these substances on intestinal activity. We have also commented on the many difficulties associated with ascribing neurotransmitter status to individual compounds. The technique of immunoblockade of neurogenic functional responses has been used in an attempt to identify some of the putative neurotransmitter substances. The search for selective antagonists continues.
Topics: Autonomic Fibers, Postganglionic; Autonomic Fibers, Preganglionic; Digestive System; Intestinal Absorption; Neurotransmitter Agents; Peristalsis
PubMed: 2564207
DOI: 10.1016/0163-7258(89)90087-9