PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Autonomic Fibers, Preganglionic”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1979

Staining of the dorsal root primary afferent fibers by anterograde movement of horseradish peroxidase and retrograde labelling of motoneurons and preganglionic autonomic cells in the turtle spinal cord.

The enzyme horseradish peroxidase (HRP) has been applied to the proximal stumps of severed thoracic and lumbar dorsal roots in the turtles Pseudemys scripta elegans and Testudo hermanni. The results obtained confirm the distribution pattern observed with anterograde degeneration techniques. Primary afferent terminal structures, however, could be demonstrated in more detail. Commonly, ventral roots were also more or less damaged which resulted in the presence of retrogradely labeled motoneurons and small cells in area X. This group of retrogradely labeled small neurons probably represents cells of origin of preganglionic autonomic fibers.

Animals↗
PubMedDate not supplied

Splanchnic preganglionic neurons in man. III. Morphometry of myelinated fibers of rami communicantes.

The myelinated fiber (MF) composition of T6-T8 Rami Communicantes were obtained in 9 healthy persons of various ages. The textbook picture that distal rami (DR) contain all of the myelinated fibers and therefore are white, while proximal rami (PR) contain none of them and therefore are grey must be modified. We found that DR usually contained abundant MFs and that PR concordance was found between segmental numbers of intermediolateral nuclei cytons, ventral root small myelinated fibers (SMFs), and rami total small MFs to suggest that both rami probably contain the distal myelinated axons of preganglionic autonomic fibers. Finally, there was an attrition of total MFs of rami with age, similar to what we had previously found for ILC cytons and for root SMFs. The decrease in number of pre-ganglionic autonomic neurons with age is thought to be of sufficient magnitude to account for the dysautonomia of the elderly.

Adult↗
PubMedDate not supplied

The morphometric myelinated fiber composition of D11 as compared to L3, L4, and L5 ventral spinal roots of man.

As compared to the diameter frequency distribution of myelinated fibers of L3, L4 and L5 ventral spinal roots (VSRs) which have two well developed peaks [large-diameter axons (AL) and intermediate-diameter axons (AI)] and a poorly developed or non-existent peak of small-diameter axons (AS), D11 VSRs contain small AL and AI peaks and a prominent AS peak. Because the ratio of AL to AI myelinated fibers of D11 VSRs is similar to that in L3, L4 and L5 VSRs and it is known that D11 VSRs contain many pre-ganglionic autonomic fibers it seems likely that AS is composed predominantly of preganglionic autonomic fibers. The mean diameter of the AS peak in D11 VSRs is approximately 2.4 micrometer. Average numbers of AS, AI and AL myelinated fibers for D11 VSRs are 3835, 738, and 1545 per root. These values should be useful as controls for morphometric studies of various neuropathies. The average diameter positions of the peak of AL, AI and AS of D11 VSRs as compared to those of L3, L4 and L5 are displaced to smaller diameter categoried which may reflect the smaller axon diameters of neurons which are shorter.

Adolescent↗
PubMed1986

Immunohistochemical demonstration of choline acetyltransferase-immunoreactive preganglionic nerve fibers in guinea pig autonomic ganglia.

The distribution of choline acetyltransferase (ChoAcTase)-like immunoreactivity in the superior cervical ganglion and the stellate ganglion was analyzed with immunohistochemistry. A dense network of ChoAcTase-immunoreactive nerve fibers was observed in both ganglia studied. The ChoAcTase-positive fibers were found in all parts of the ganglia but had a differential distribution, giving rise to a patchy staining pattern. After preganglionic denervation of the superior cervical ganglia, all ChoAcTase-positive fibers disappeared. For comparison, the distributions of enkephalin- and neuropeptide Y-like immunoreactivity were analyzed. In the stellate ganglion, the enkephalin-positive fibers had a marked regional distribution. Areas with the highest enkephalin-fiber density seemed to contain low numbers of ChoAcTase-positive fibers and vice versa. The findings give evidence for occurrence of acetylcholine synthesis in preganglionic fibers in paravertebral sympathetic ganglia.

Acetylcholine↗
PubMed1984

Primary afferent projections from dorsal and ventral roots to autonomic preganglionic neurons in the cat sacral spinal cord: light and electron microscopic observations.

HRP applied to cut dorsal and ventral roots of the cat sacral spinal cord labeled afferent axons with swellings in close apposition to labeled preganglionic neurons (PGNs) in the sacral parasympathetic nucleus. Electron microscopy allowed characterization of synaptic contacts between afferents and PGNs. The results suggest that both the dorsal and ventral root afferents can directly activate autonomic preganglionic neurons.

Animals↗
PubMed1987

Differential use-dependent (frequency-dependent) effects in single mammalian axons: data and clinical considerations.

The potential clinical scope of use-dependent block of conduction (UDB) was assessed by studying characteristics of UDB in vitro in individual mammalian axons. Single and repetitive stimulation was applied to rabbit cervical sympathetic and vagus nerves exposed to solutions containing lidocaine 0, 0.3, or 0.6 mmol/l (9.1 or 18.2 mg/dl) at 37 degrees C. Unit responses were recorded in dissected filaments or extracellularly in the vagus nodose ganglion. With lidocaine 0.3 mM, equilibrium conduction block, tested by single shocks, was rare. 40-Hz trains produced a significantly greater increase in latency (slowing of conduction) and a much greater incidence of UDB in the sympathetic units than in myelinated vagus axons of equivalent control conduction velocities or in unmyelinated axons. 10-Hz stimulation did not produce UDB. With lidocaine 0.6 mM, the incidence of equilibrium conduction block was too high among sympathetic axons to assess UDB, and significantly higher than among nonsympathetic myelinated and unmyelinated units. The observations support the hypothesis that the differential block of sympathetics observed clinically with spinal anesthesia may be, at least in part, a use-dependent (frequency-dependent) effect. UDB seems unlikely to contribute to local anesthetic block of pain impulses.

Anesthesia, Spinal↗
PubMedDate not supplied

Posttetanic potentiation in decentralized and nondecentralized superior cervical ganglia of the cat.

The present investigation was aimed to answer the following elementary, though important question concerning the sympathetic ganglion: Do the decentralized preganglionic terminals retain their full capacity to develop posttetanic potentiation (PTP) before substantial Wallerian degeneration takes place? Experiments were performed on the cat superior cervical ganglion in situ, and they followed a factorial design. The factors were: tetanization (supramaximal pulses, 0.2 ms, 24 Hz, 30 s), acute decentralization, and moderate hexamethonium blockade (5 mg/kg). Two levels were dealt with, namely, the indicated maneuvers were either performed or not performed. PTP was was measured in the S2 wave and the following variables were studied: decay constant, area under the curve and delay to summit occurrence. The analysis of variance showed that decentralization did not affect the development of PTP. Therefore, the nondegenerated terminals are fully capable of sustaining PTP, without the aid of the preganglionic cell bodies.

Action Potentials↗
PubMed1980

Autonomic innervation of the tongue: a horseradish peroxidase study in the dog.

Autonomic ganglia have been found along the lingual nerve in the rostral two-thirds of the canine tongue and along the glossopharyngeal nerve in the caudal glandular third of the tongue [4,17,18]. A 30% horseradish peroxidase (HRP) solution was injected throughout these ganglionated areas in order to identify the origin of the preganglionic fibers to the lingual ganglia. These injections resulted in ipsilateral retrograde labeling of small multipolar neurons in the lateral reticular formation of the medulla oblongata. The same injections labeled neurons in the ipsilateral cranial cervical ganglion, but preganglionic sympathetic neurons in the thoracic spinal cord were not labeled. These findings indicated that the lingual ganglia consist of parasympathetic neurons which receive preganglionic projections from the medulla. The lingual preganglionic neurons were located within the nucleus reticularis parvicellularis and, in this location, were co-extensive with salivatory neurons that labeled after HRP injections in the mandibular and sublingual salivary glands. A degree of somatotopic organization within the lingual preganglionic group was indicated by the results of regional injections of enzyme and was confirmed by performing unilateral chorda tympani and glossopharyngeal neurectomies prior to extensive bilateral injections of HRP.

Animals↗
PubMed1996

Axonal transport of nitric oxide synthase in autonomic nerves.

By using mechanical nerve ligation or nerve pinch technique, we provide evidence that nitric oxide synthase (NOS) is transported in the preganglionic sympathetic axons, while postganglionic axons lack NOS transport. This finding corroborates the preganglionic sympathetic terminal as the site of NO synthesis, which is known to affect ganglionic transmission. Both vasoactive intestinal polypeptide (VIP) and substance P (SP) containing neurons of the nodose ganglion transport NOS in their axons. These results therefore suggest that NOergic innervation of autonomically innervated tissues is of parasympathetic and/or sensory, rather than sympathetic, origin.

Animals↗
PubMed1982

Progressive isolated segmental anhidrosis.

A patient had progressive segmental anhidrosis, which proved after extensive neurologic and autonomic workup to be an isolated abnormality. Intradermal acetylcholine produced localized sweating in areas of thermoregulatory anhidrosis five months after the onset of symptoms but failed to do so at two years. These findings are consistent with a preganglionic sympathetic lesion affecting a functionally defined subset of sympathetic cells and/or fibers. The alteration of the sudomotor response to intradermal acetylcholine during the course of the illness suggests that the diagnostic utility of pharmacologic sweat tests may be time dependent, limited to a relatively early period following onset of anhidrosis.

Acetylcholine↗
PubMed1997

Location, immunohistochemical features, and spinal connections of autonomic neurons innervating the rat seminal vesicles.

With the use of retrograde tracing techniques, selective spinal nerve transections, and immunohistochemistry to label noradrenergic and peptidergic pathways, this study has for the first time defined in detail the autonomic innervation to the rat seminal vesicles. The majority of this innervation originates from the bilateral major pelvic ganglia, whereas very few neurons are located in the accessory, inferior mesenteric, or paravertebral chain ganglia. Neuropeptide Y was the most abundant marker, followed by tyrosine hydroxylase (an enzyme involved in noradrenaline synthesis), and then vasoactive intestinal peptide. Sympathetic axons with tyrosine hydroxylase and neuropeptide Y supplied vascular and nonvascular smooth muscle whereas parasympathetic, cholinergic neuropeptide Y terminals were associated with the glandular epithelium. In contrast, vasoactive intestinal peptide was found only in cholinergic neurons, which may have either parasympathetic or sympathetic spinal connections. The latter were far more prevalent, demonstrating a substantial sympathetic cholinergic innervation to the seminal vesicles. Vasoactive intestinal peptide axons were associated with the glandular epithelia, as well as vascular and nonvascular smooth muscle. Axons associated with the secretory epithelia may regulate secretion or perhaps provide trophic support. Finally, acute damage to preganglionic sacral and lumbar nerves caused a transient increase in glandular weight.

Animals↗