Parasympathetic Fibers Research Articles

Parasympathetic Vasodilator Fibers in the Orofacial Region

The present report focuses on a review of A) the parasympathetic vasodilator fibers in the orofacial skin, B) the central mechanism by which trigeminal stimulation elicits parasympathetic reflex vasodilatation, and C) the presence of parasympathetic vasodilator fibers in the jaw muscles. A) The parasympathetic neurons, particularly those running as efferents in the glossopharyngeal nerve, were involved in vasodilatation elicited by stimulation of the infra-orbital nerve and the maxillary buccal gingiva. Furthermore, the vasodilator response was not affected by lesion of the pterygopalatine ganglion, suggesting that reflex vasodilatation is mediated via the otic ganglion but not via the pterygopalatine ganglion. B) The trigeminal spinal nucleus is an important bulbar relay for lingual nerve-evoked parasympathetic reflex vasodilatation in the lower lip. C) There are parasympathetic cholinergic and non-cholinergic vasodilator fibers originating from cell bodies in the otic ganglion in the rat masseter muscle, and that these fibers are reflexly activated by trigeminal afferent nerve stimulation. The physiological function of the parasympathetic vasodilator fibers in the orofacial area is unknown. However, it has recently been suggested that the trigeminal system may participate in autonomic and behavioral functions such as feeding and drinking. The present review adds a new facet to the evidence that there is a close link between parasympathetic vasodilator fibers and the trigeminal system in the facial area.

A new instrument for rectal suction biopsy in the diagnosis of Hirschsprung′s disease: Triple rectal suction biopsy

A new instrument for suction rectal biopsy in infants suspected of having Hirschsprung's disease is described that can be completely dismantled, physically cleaned, lubricated, and heat sterilised. Triple rectal suction biopsy instrument with the patent application, which involves (0.5 cm diameter) suction of mucosa and sub-mucosa and provides taking three different biopsies within a 2 cm distant from each other with a single shot, instead of only one or taking a full layer biopsy under general anesthesia for the diagnosis of Hirschsprung disease. As a preliminary study, in the 36 and 12 biopsy materials taken from the rabbits and children, respectively, it was found that mucosa and sub-mucosa were sufficient and in all of the cross sections, parasympathetic nerve fibers, and ganglion cells were existed. A successful biopsy was usually achieved and no complications occurred.

Treatment of Idiopathic Gustatory Rhinorrhea by Resection of the Posterior Nasal Nerve

We herein describe a case of 44-year old female who presented with a chief complaint of gustatory rhinorrhea from childhood, in which gustatory stimuli caused bilateral excessive, watery nasal secretion. No abnormality of taste acuity was observed. This disorder was presumably caused by faulty regenerated parasympathetic nerve fibers reaching the nasal mucosa or possibly, by a congenital condition. Nasal pretreatment with an anti-cholinergic drug clinically blocked the positive sugar-induced rhinorrhea, thus indicating that the gustatory rhinitis in this case was produced by foods that stimulate muscarinic receptors sensitive to atropine (probably on submucosal nasal glands). Although this syndrome can be treated prophylactically by the use of topical atropine, the patient preferred to undergo radical therapy and a resection of the posterior nasal nerve was performed through the middle meatus under endoscopic control. The resection of the nerve on both sides resulted in an almost complete inhibition of the sugar-induced rhinorrhea without serious complications. Although this disease is not life-threatening, it is socially embarrassing and troublesome to patients and surgical therapy is one of the accepted modalities.

Erratum to “Peptidergic sensory and parasympathetic fiber sprouting in the mucosa of the rat urinary bladder in a chronic model of cyclophosphamide-induced cystitis”: [Neuroscience 139 (2006) 671–685

Erratum to “Peptidergic sensory and parasympathetic fiber sprouting in the mucosa of the rat urinary bladder in a chronic model of cyclophosphamide-induced cystitis”: [Neuroscience 139 (2006) 671–685

Novel presentation of retroperitoneal germ cell tumor with loss of ejaculation but preservation of erection in two patients

To examine the effect of large-volume retroperitoneal germ cell tumor on nerve fibers required for erection and ejaculation. Retrospective case reports. Cancer treatment center. Two male patients presenting with loss of ejaculation but preservation of erection. Retroperitoneal lymph nodes lie very close to the sympathetic nerve fibers that control ejaculation. Large-volume tumors would encase the sympathetic plexuses at L1 to L3, making ejaculation impossible. Parasympathetic fibers arise from S2 to S4, so they would not be damaged, preserving erection. Thorough history taking is important in the investigation of infertility. Presentation with these symptoms requires further investigation at an early stage to exclude retroperitoneal tumor.

Evidence for parasympathetic vasodilator fibres in the rat masseter muscle

The present study was designed to examine (1) whether there are vasodilator fibres in the masseter muscle, and (2) if there are, to establish the neural pathways mediating these responses in urethane-anaesthetized rats. Electrical stimulation of the central cut end of the lingual nerve (LN) elicited intensity- and frequency-dependent increases of the blood flow in the masseter muscle (MBF) and lower lip (LBF). Increases in both the MBF and LBF evoked by the LN stimulation were reduced by hexamethonium in a dose-dependent manner (1-10 mg kg(-1)). Pretreatment with phentolamine or propranolol at a dose of 100 microg kg(-1) had no effect on the increases in either MBF or LBF evoked by LN stimulation. Pretreatment with atropine (100 microg kg(-1)) significantly reduced the MBF increase induced by LN stimulation, but not that in the LBF. The sectioning of the superior cervical sympathetic trunk did not affect the responses. MBF increases occurred with electrical stimulation of the trigeminal ganglion, and these increases were significantly reduced by the administration of hexamethonium and atropine. Lidocaine microinjection into the trigeminal spinal nucleus or salivatory nuclei caused a significant attenuation of the LN-induced MBF increases. When wheat germ agglutinin-horseradish peroxidase (WGA-HRP) was injected into the masseter muscle, labelled neurones were abundantly observed in the otic ganglion. The present study indicates that there are parasympathetic cholinergic and noncholinergic vasodilator fibres originating from cell bodies in the otic ganglion in the rat masseter muscle. The MBF increase evoked by activation of the parasympathetic fibres occurred via the trigeminal mediated reflex, suggesting that the novel parasympathetic vasodilator response may play an important role in the regulation of the haemodynamics of jaw muscles.

The pleura, lobes and microstructure of the lungs

The pleura is a double-walled serous lined sac. The outer layer clothes the chest wall and diaphragm, the inner (visceral) layer adheres to the lung: the two meet at the hilum. Between these two layers is the potential space of the pleural cavity, moistened by a film of serous fluid. The mediastinum is the space between the two pleural sacs. The right lung is larger than the left and comprises the upper, middle and lower lobes. The left lung has an upper and lower lobe separated by the oblique fissure. On the right an additional transverse fissure separates the upper and middle lobes. The hilum of the lung contains, within its pleural sheath, the main bronchus, pulmonary artery and vein, bronchial vessels, hilar lymph nodes and lymphatics, and autonomic sympathetic and parasympathetic (vagal) fibres. The epithelium comprises columnar ciliated cells and mucus secreting goblet cells down to the finer bronchi, while the alveoli are free from goblet cells and the epithelium comprises a thin membrane. The alveoli also contain large vacuolated cells that produce the phospholipid component of surfactant. Below the mucosa, the bronchial wall is made up of a basement membrane, submucous elastic tissue, non-striated muscle, and an outer fibrous coat containing cartilage. At each bifurcation there is a saddle-shaped piece of cartilage, which reinforces the two branches at their division.

2-Agonist and Anticholinergic Drugs in the Treatment of Lung Disease

The lungs are innervated by both the sympathetic and parasympathetic nervous systems, which entails the activation of adrenergic and muscarinic receptors, respectively. Both the adrenergic and muscarinic receptors are G-protein-coupled receptors, and they share many similar signal transduction molecules. These receptors are widely expressed in the lung and the specific receptor expression can vary among the species. The location and the subtype of receptor expressed are important in the regulation of normal airway function. Acetylcholine released from the parasympathetic fibers activates the M3 muscarinic receptors located on the airway smooth muscle, causing bronchoconstriction. To counter this activity, M2 muscarinic receptors located on the parasympathetic nerves inhibit release of acetylcholine. Beta2-adrenergic receptors are expressed on the airway smooth muscle where activation causes bronchodilation. Adrenergic receptors are also on the autonomic nerves where they can modulate neurotransmitter release. The crosstalk between these G-protein-coupled receptors and downstream pathways ensures normal airway function. The prejunctional and postjunctional muscarinic and adrenergic receptors control autonomic tone and any imbalance or selective blockade of the receptors can compromise the system and cause the airways to become hyperreactive. The location, function, and crosstalk of the adrenergic and muscarinic receptors must be considered in the design, development, and use of drugs to combat airway diseases.

Taste Cell Responses in the Frog Are Modulated by Parasympathetic Efferent Nerve Fibers

We studied the anatomical properties of parasympathetic postganglionic neurons in the frog tongue and their modulatory effects on taste cell responses. Most of the parasympathetic ganglion cell bodies in the tongue were found in extremely small nerve bundles running near the fungiform papillae, which originate from the lingual branches of the glossopharyngeal (GP) nerve. The density of parasympathetic postganglionic neurons in the tongue was 8000-11,000/mm(3) of the extremely small nerve bundle. The mean major axis of parasympathetic ganglion cell bodies was 21 microm, and the mean length of parasympathetic postganglionic neurons was 1.45 mm. Electrical stimulation at 30 Hz of either the GP nerve or the papillary nerve produced slow hyperpolarizing potentials (HPs) in taste cells. After nicotinic acetyl choline receptors on the parasympathetic ganglion cells in the tongue had been blocked by intravenous (i.v.) injection of D-tubocurarine (1 mg/kg), stimulation of the GP nerve did not induce any slow HPs in taste cells but that of the papillary nerve did. A further i.v. injection of a substance P NK-1 antagonist, L-703,606, blocked the slow HPs induced by the papillary nerve stimulation. This suggests that the parasympathetic postganglionic efferent fibers innervate taste cells and are related to a generation of the slow HPs and that substance P is released from the parasympathetic postganglionic axon terminals. When the resting membrane potential of a taste cell was hyperpolarized by a prolonged slow HP, the gustatory receptor potentials for NaCl and sugar stimuli were enhanced in amplitude, but those for quinine-HCl and acetic acid stimuli remained unchanged. It is concluded that frog taste cell responses are modulated by activities of parasympathetic postganglionic efferent fibers innervating these cells.

Clinical and subclinical autonomic dysfunction in chronic inflammatory demyelinating polyradiculoneuropathy

Autonomic neuropathy, although common in Guillain-Barré syndrome, is considered rare in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and has not been systematically investigated in that disorder. The present study was aimed at determining the prevalence of autonomic dysfunction and investigating the integrity of autonomic nervous system (ANS) reflexes in CIDP. We studied 17 patients with idiopathic CIDP and 20 healthy controls. Six quantitative autonomic function tests (AFTs) were used: Valsalva ratio, 30/15 ratio, and inspiration-expiration difference for parasympathetic function; and tilt test, handgrip test, and sympathetic skin response for sympathetic function. Eleven patients had symptoms of autonomic dysfunction. AFTs were abnormal in 13 patients. Parasympathetic and sympathetic systems were affected with equal frequency. The tilt test was abnormal most frequently, followed by the 30/15 ratio. Three patients developed postural hypotension with loss of consciousness during the tilt test. Abnormality of AFTs did not correlate with the presence of dysautonomic symptoms; duration, severity, and clinical course of the disease; or with age or gender of patients. Our study suggests a higher frequency of clinical and subclinical involvement of the ANS in CIDP than previously estimated. Dysautonomic symptoms are frequent but are mild. However, upon prolonged passive standing, autonomic failure can lead to loss of consciousness. The subclinical involvement of the ANS affects mainly the sympathetic vasomotor and parasympathetic cardiovascular fibers.

Accidental Caudal Injection of Rocuronium in an Awake Patient

Accidental Caudal Injection of Rocuronium in an Awake Patient

Atrial and ventricular rat coronary arteries are differently supplied by noradrenergic, cholinergic and nitrergic, but not sensory nerve fibres

The present immunohistochemical study set out to determine the extent of perivascular innervation in the rat heart, using markers for noradrenergic sympathetic fibres (tyrosine hydroxylase = TH), cholinergic parasympathetic fibres (vesicular acetylcholine transporter = VAChT), nitrergic fibres (neuronal NO synthase = nNOS), and peptidergic sensory fibres (calcitonin gene-related peptide = CGRP). For each of these antigens, the vascular innervation density was assessed separately in the atria, the basal and the apical parts of the ventricles, and was correlated to the inner vascular diameter. The four major findings are: (1) Each of these neurochemically defined populations shows an individual distribution pattern significantly different from the others with respect to correlation with vascular diameter and occurrence along atrial versus ventricular vessels. (2) Among autonomic efferent axons, nNOS-containing fibres are far less numerous than cholinergic and noradrenergic fibres. (3) Autonomic efferent axons (noradrenergic, cholinergic, nitrergic) are much more abundant around atrial than ventricular vessels, whereas perivascular CGRP-immunoreactive sensory nerve fibres are equally distributed in the various parts of the heart. (4) Noradrenergic and cholinergic axons preferentially innervate small-diameter vessels (negative linear correlation between index of innervation and vascular diameter), whereas the supply with CGRP-immunoreactive sensory nerve fibres does not change with vascular diameter. Collectively, the present study shows individual distribution patterns for each of the neurochemically defined populations of perivascular axons along the atrial and ventricular coronary arteries, indicating a highly differentiated nervous regulation of atrial versus ventricular, and large-diameter versus resistance vessels.

Selective block of external anal sphincter activation during electrical stimulation of the sacral anterior roots in a canine model

Our aim was to electrically activate small diameter parasympathetic fibres in the sacral anterior roots, without activating the larger somatic fibres to the external anal sphincter (EAS). Electrodes were implanted on selected roots in five adult dogs. Pressures were recorded from the rectum and EAS. Quasitrapezoidal (Qzt) pulses for selective activation of smaller axons and narrow rectangular (Rct) pulses to activate all fibres were applied. Sphincter block was defined as [(P(max) - P(min))/P(max)] x 100%. Roots were also tested with 20 Hz trains. In three animals, evacuation of bowel contents was recorded with artificial fecal material. Stimulation with Qzt pulses showed decrease in sphincter recruitment with increasing pulse amplitudes, indicating propagation arrest in the large fibres. The average sphincter suppression was 94.1% in 16 roots implanted. With Qzt pulse trains, the average evoked sphincter pressure was significantly lower than Rct pulses. Evoked rectal pressures were not significantly different. The mean mass of expelled bowel contents of 51.1 g by Qzt trains was significantly higher than that of 14.8 g expelled by Rct trains. Our results demonstrate that this selective stimuli can activate small diameter fibres innervating the distal bowel and result in significant evacuation of rectal contents.

Autonomic fibre sprouting and changes in nociceptive sensory innervation in the rat lower lip skin following chronic constriction injury

In this study we used immunocytochemistry to investigate whether autonomic fibres sprouted in the skin of the lower lip in a rat model of neuropathic pain. We used a bilateral chronic constriction injury (CCI) of the mental nerve (MN), a branch of the trigeminal nerve. In this model, we also studied the accompanying changes in peptidergic [calcitonin gene-related peptide (CGRP)-immunoreactive] sensory fibres, as well as in trkA receptor immunoreactivity in the sensory nerves. Autonomic (sympathetic and parasympathetic) fibre sprouting was first observed 1 week post-injury with a peak in the number of sprouted fibres occurring at 4 and 6 weeks post-CCI. CGRP-IR fibres almost disappeared at 2 weeks post-CCI, but quickly sprouted, leading to a significant peak above sham levels 4 weeks post-injury. trkA receptor expression was found to be up-regulated in small cutaneous nerves 4 weeks post-CCI, returning to sham levels by 8 weeks post-CCI. There was no sympathetic fibre sprouting in the trigeminal ganglion following CCI. At 4 weeks post-CCI, rats displayed spontaneous, directed grooming to the area innervated by the MN that was not seen in sham animals, which we interpreted as a sign of spontaneous pain or dysesthesiae. Collectively, our findings indicate that as a result of autonomic sprouting due to CCI of the MN, remaining intact nociceptive fibres may potentially develop sensitivity to sympathetic and parasympathetic stimulation, which may have a role in the generation of abnormal pain following nerve injury.

Parasympathetic Innervation and Function of Endocrine Pancreas Requires the Glial Cell Line–Derived Factor Family Receptor α2 (GFRα2)

Vagal parasympathetic input to the islets of Langerhans is a regulator of islet hormone secretion, but factors promoting parasympathetic islet innervation are unknown. Neurturin signaling via glial cell line-derived neurotrophic factor family receptor alpha2 (GFRalpha2) has been demonstrated to be essential for the development of subsets of parasympathetic and enteric neurons. Here, we show that the parasympathetic nerve fibers and glial cells within and around the islets express GFRalpha2 and that islet parasympathetic innervation in GFRalpha2 knockout (KO) mice is reduced profoundly. In wild-type mice, neuroglucopenic stress produced a robust increase in plasma levels of islet hormones. In the GFRalpha2-KO mice, however, pancreatic polypeptide and insulin responses were completely lost and glucagon response was markedly impaired. Islet morphology and sympathetic innervation, as well as basal secretions of the islet hormones, were unaffected. Moreover, a glucose tolerance test failed to reveal differences between the genotypes, indicating that direct glucose-stimulated insulin secretion was not affected by GFRalpha2 deficiency. These results show that GFRalpha2 signaling is needed for development of the parasympathetic islet innervation that is critical for vagally induced hormone secretion. The GFRalpha2-KO mouse represents a useful model to study the role of parasympathetic innervation of the endocrine pancreas in glucose homeostasis.

Erectile dysfunction after fracture of the pelvis

Male sexual dysfunction after fracture of the pelvis is more common than previously supposed with rates as high as 30% reported when the complaint is specifically sought. With the increase in survival from major injuries, the long-term consequences of trauma are being seen with increasing frequency

Heart rate variability measurements and the prediction of ventricular arrhythmias

Heart rate variability (HRV) is the temporal variation between sequences of consecutive heartbeats. On a standard electrocardiogram (ECG), the maximum upwards deflection of a normal QRS complex is at the peak of the R wave (Figure 1), and the duration between two adjacent R wave peaks is termed the R-R interval. The ECG signal requires editing before HRV analysis can be performed, a process requiring the removal of all non-sinus-node-originating beats. The resulting period between adjacent QRS complexes resulting from sinus node depolarizations is termed the N-N (normal-normal) interval.1 HRV is the measurement of the variability of the N-N intervals. Figure 1. The normal electrocardiogram with component waves labelled. Although counter-intuitive, it is possible that HRV confers a survival advantage. Any system exhibiting intrinsic variability is primed to respond rapidly and appropriately to demands placed upon it. HRV is a measure of the balance between sympathetic mediators of heart rate (HR) (i.e. the effect of epinephrine and norepinephrine, released from sympathetic nerve fibres, acting on the sino-atrial and atrio-ventricular nodes), which increase the rate of cardiac contraction and facilitate conduction at the atrio-ventricular node, and parasympathetic mediators of HR (i.e. the influence of acetylcholine, released by the parasympathetic nerve fibres, acting on the sino-atrial and atrio-ventricular nodes), leading to a decrease in the HR and a slowing of conduction at the atrio-ventricular node. Sympathetic mediators appear to exert their influence over longer time periods and are reflected in the low frequency power (LFP) of the HRV spectrum (between 0.04 Hz and 0.15 Hz.2,,3 Vagal mediators exert their influence more quickly on the heart, and principally affect the high frequency power (HFP) of the HRV spectrum (between 0.15 Hz and 0.4 Hz).4 Thus, at any point in time, the LFP:HFP ratio is a proxy for the sympatho-vagal balance. Physiological and pathological process … Address correspondence to Dr M.J. Reed, Emergency Department, Royal Infirmary of Edinburgh, 51 Little France Crescent, Edinburgh EH16 4SA. e-mail: mattreed1{at}hotmail.com

Effects of capsaicin and nitric oxide synthase inhibitor on increase in cerebral blood flow induced by sensory and parasympathetic nerve stimulation in the rat

Effects of electrical stimulation of the nerve bundles including sensory and parasympathetic nerves innervating cerebral arteries on cerebral blood flow (CBF) and mean arterial blood pressure (MABP) were investigated with a laser-Doppler flowmeter and a blood pressure monitoring system in anesthetized rats pretreated with and without capsaicin. The electrode was hooked on the nerve bundles including the distal nasociliary nerve from trigeminal nerve and parasympathetic nerve fibers from sphenopalatine ganglion. In control rats, the nerve stimulation for 30 s increased CBF in the ipsilateral side and MABP. Hexamethonium attenuated the increase in CBF and abolished that in MABP. Under treatment with hexamethonium, N(G)-nitro-L-arginine (L-NNA, 1 mg/kg) significantly attenuated the stimulation-induced increase in CBF, which was restored by the addition of L-arginine. Although the dose of L-NNA was raised up to 10 mg/kg, the stimulation-induced increase in CBF was not further inhibited and was never abolished. In capsaicin-pretreated rats, magnitudes of the stimulation-induced increases in CBF and MABP were lower than those in control rats. Hexamethonium attenuated the increase in CBF and abolished that in MABP. Under treatment with hexamethonium, L-NNA abolished the stimulation-induced increase in CBF in capsaicin-pretreated rats. In conclusion, nitric oxide released from parasympathetic nerves and neuropeptide(s) released antidromically from sensory nerves may be responsible for the increase in CBF in the rat. The afferent impulses by nerve stimulation may stimulate the trigeminal nerve and lead to the rapid increase in MABP, which partly contributes to the increase in CBF.

Distribution of Catecholaminergic Neurotransmitters and Related Receptors in Human Bronchus-Associated Lymphoid Tissue

Background: The functions of the bronchus-associated lymphoid tissue (BALT) are under the control of the autonomic nervous system (sympathetic and parasympathetic nerve fibers). Objectives: The relationships between the adrenergic nerve fibers and β-adrenergic receptors were studied in the human BALT with the aim to demonstrate a probable neuromodulation. Methods: Morphological observations (staining with hematoxylin-eosin and scanning electron microscopy images) were carried out on samples of human BALT harvested during autopsies. Moreover, histochemical staining for norepinephrine (adrenaline = adrenergic nerve fibers) as well as for other catecholamines was performed. Finally, β-adrenergic receptors were stained by means of a β-blocking, radiolabeled drug (pindolol ¹²⁵I). All our data were submitted to morphometric analysis (quantitative analysis of images and statistical analysis of data). Results: Our results provide direct evidence of the presence and distribution of catecholaminergic nerve fibers and related β-adrenergic receptors in BALT. β-Adrenergic receptors are present above all in the most richly innervated part of the BALT, and are, therefore, in close relationship with their related adrenergic nerve fibers. Conclusions: Studies on the distribution of adrenergicneurotransmitters and related β-adrenergic receptors in the human BALT are the first step for the demonstration of a probable neuromodulation of BALT.

Different pulse shapes for selective large fibre block in sacral nerve roots using a technique of anodal block: An experimental study

The aim of this study was experimentally to investigate whether it is possible to reduce the charge per phase that is applied during selective large fibre block. Sacral roots in pigs were stimulated. Sacral roots contain large somatic nerve fibres and small parasympathetic nerve fibres. Large nerve fibres that innervate the external urethral and external anal sphincters were selectively blocked using a technique of anodal block. In that way, selective activation of the detrusor muscle and the rectum innervated by parasympathetic fibres could be obtained. The square stimulation pulse was replaced with three different pulse shapes that had the same duration as the square pulse and consisted of a depolarising prepulse and a blocking part of the pulse. Compared with the square pulse, the charge per phase needed for anodal block could be reduced with all three pulse shapes. Maximum reduction of the charge per pulse was 17+/-6%. A lower charge might make anodal block safer in long-term applications.