Journal of the autonomic nervous system最新文献

Voiding difficulty is a common feature in neurological diseases, which can be attributed to dysfunction of the urethral sphincter and the detrusor. Electromyography (EMG)–cystometry can reveal the presence of detrusor–external sphincter dyssynergia (DESD), however, internal sphincter function on voiding is not easily evaluated. Pressure–flow study is widely used to diagnose benign outlet obstruction due to prostatic hypertrophy. We applied pressure–flow study in neurological patients in order to evaluate neurogenic urethral relaxation failure. We recruited 71 patients with neurological diseases. All were men under 60 years, with mean age of 44 years, ranging from 18 to 59 years. None had abnormal finding of digital examination or ultrasound echography of the prostate. Standard cystometry showed detrusor hyperreflexia in 33 patients and residual urine was noted in 36. DESD was noted in seven of 43 patients. Pressure–flow relation curve and a detrusor pressure (P_det) at the point of maximum flow rate (Q_max) (i.e., P_detQ_max) were obtained by urodynamic computers. The Abram–Griffiths (AG) number (P_detQ_max−2Q_max), showing outlet obstruction particularly over 40, was also obtained. The points of P_detQ_max of the patients fell into three categories of the AG nomogram, showing obstruction in 19.7%, equivocal in 52.1% and unobstructed in 28.2%. Patients with DESD had AG number over 40 more commonly (57.1%) than those without DESD (8.4%) (p<0.05). The mean AG number was 46.4 in patients with DESD, which was larger than 17.1 in patients without DESD (p<0.01). Patients with detrusor hyperreflexia had AG number over 40 more commonly (42.4%) than those with normal cystometric curve (0%) (p<0.01). The mean AG number was 30.6 in patients with detrusor hyperreflexia, which was larger than 13.6 in patients with normal cystometric curve (p<0.01). The results showed that 19.7% of patients with neurological diseases had obstructive pattern (high pressure voiding), evidence of urethral relaxation failure with relatively preserved detrusor contraction. DESD is a factor contributing to the urethral relaxation failure of the patients. The results also indicated a relationship between detrusor hyperreflexia and obstructed pattern, probably reflecting co-occurrence of detrusor hyperreflexia with DESD or detrusor–internal sphincter dyssynergia.

The contribution of the vagus nerve to viral transneuronal labeling of brain structures from the ovaries demonstrated recently by us was investigated. Unilateral vagotomy was performed prior to ipsilateral intraovarian virus injection. Virus-infected neurons were visualized by immunostaining. In vagotomized rats such neurons were detected only in certain cell groups of the brain (parapyramidal nucleus, A₁, A₅ cell group, caudal raphe nuclei, hypothalamic paraventricular nucleus, lateral hypothalamus). Vagotomy interfered with labeling of several structures that were labeled in controls, including area postrema, nucleus of the solitary tract, dorsal vagal complex, nucleus ambiguus, A₇ cell group, Barrington’s nucleus, locus coeruleus, periaqueductal gray, dorsal hypothalamus. Findings provide a morphological basis to study the functional significance of brain structures presumably involved in the control of ovarian function and acting via the vagus or the sympathetic nerves.

The distribution, chemical coding and origin of nitric oxide synthase (NOS)-containing nerve fibres in the respiratory mucosa of the nasal septum of the guinea pig were examined using nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) histochemistry and immunohistochemistry. A rich supply of NADPH-d-positive nerve fibres was observed around blood vessels and in nasal glands where nerve fibres frequently penetrated into the epithelia of acini and intralobular ducts. NADPH-d reactivity was also found in the nerve fibres located under or within the respiratory epithelium. Combined immunofluorescence and histochemical staining of the same preparation demonstrated virtually complete overlapping of NOS immunoreactivity and NADPH-d reactivity in nerve fibres, indicating that NADPH-d can be used as a marker for NOS-containing neurons. Double-labelling using antibodies to vasoactive intestinal polypeptide (VIP), neuropeptide Y (NPY), and calcitonin gene-related peptide (CGRP) revealed that NADPH-d-positive nerve fibres frequently contained VIP or NPY, but not CGRP. Pterygopalatine ganglionectomy significantly reduced the number of NADPH-d-positive nerve fibres innervating the respiratory epithelium as well as blood vessels and nasal glands. Neither superior cervical ganglionectomy nor sensory denervation by capsaicin treatment affected the distribution of NADPH-d-positive fibres. These results indicate that NOS-containing nerve fibres innervating the respiratory epithelium as well as blood vessels and nasal glands in the guinea pig originate mainly from the pterygopalatine ganglion, and suggest that NO may play a significant role as a neurotransmitter and/or neuromodulator in the control of the respiratory epithelium as well as vasculature and nasal glands.

Glial fibrillary acidic protein- (GFAP) and calbindin D28k-immunoreactivity (IR) were investigated in the medial subdivision of the nucleus of the solitary tract (mNST) of prenatally X-irradiated rats. Pregnant rats were exposed to a single whole-body X-irradiation on day 11 or 16 of gestation at a dose of 1.3 Gy. The offspring were killed at 7–14 days of age for the immunohistochemical observations. Rat pups showed strong GFAP-IR at the level rostral to the obex when receiving X-rays on day 11 of gestation, with hypertrophy of astrocyte cell bodies and cytoplasmic processes, but weak GFAP-IR when receiving X-rays on day 16 of gestation. Calbindin D28k-IR was stronger in the animals receiving X-rays on day 11 or 16 of gestation compared to that in the control animals. In the present study, the increase of GFAP- and calbindin D28k-IR cells in the mNST might indicate that adaptative mechanisms are taking place to preserve integrated nervous system function and possibly, to provide neuroprotection.

Disordered gut motor activity is a feature of patients with Chagas’ disease: colonic involvement leads to the development of megacolon and symptoms of constipation. Interstitial cells of Cajal are thought to modulate gut motility. The aim of this study was to test the hypothesis that there is an abnormality of the density of distribution of interstitial cells of Cajal in Chagasic megacolon. Interstitial cells of Cajal were identified by immunohistochemistry using an anti-c-kit antibody. Six patients with Chagasic megacolon were compared with normal controls. The density of distribution of interstitial cells of Cajal was assessed in the longitudinal and circular muscle layers, and in the intermuscular plane of the Chagasic and normal colon. Statistical analysis was performed using Fisher’s exact test. The interstitial cells of Cajal density in Chagasic megacolon was much reduced in comparison to normal colonic tissue in the longitudinal muscle layer (P=0.0084), intermuscular plane (P<0.0001), and circular muscle layer (P=0.0051). The lack of interstitial cells of Cajal may play a role in the pathophysiology of the disease, leading to the development of megacolon and symptoms of constipation.

Six-degree head-down tilt (HDT) is well accepted as an effective weightlessness model in humans. However, some researchers utilized lower body positive pressure (LBPP) to simulate the cardiovascular and renal effects of a decreased gravitational stress. In order to determine whether LBPP was a suitable model for simulated weightlessness, we compared the differences between these two methods. Ten healthy males, aged 21–41 years, were subjected to graded LBPP at 10, 20 and 30 mm Hg, as well as 6° HDT. Muscle sympathetic nerve activity (MSNA) was microneurographically recorded from the tibial nerve along with cardiovascular variables. We found that MSNA decreased by 27% to a similar extent both at low levels of LBPP (10 and 20 mm Hg) and HDT. However, at a high level of LBPP (30 mm Hg), MSNA tended to increase. Mean arterial pressure was elevated significantly by 11% (10 mm Hg) at 30 mm Hg LBPP, but remained unchanged at low levels of LBPP and HDT. Heart rate did not change during the entire LBPP and HDT procedures. Total peripheral resistance markedly increased by 36% at 30 mm Hg LBPP, but decreased by 9% at HDT. Both stroke volume and cardiac output tended to decrease at 30 mm Hg LBPP, but increased at HDT. These results suggest that although both LBPP and HDT induce fluid shifts from the lower body toward the thoracic compartment, autonomic responses are different, especially at LBPP greater than 20 mm Hg. We note that high levels of LBPP (>20 mm Hg) activate not only cardiopulmonary and arterial baroreflexes, but also intramuscular mechanoreflexes, while 6° HDT only activates cardiopulmonary baroreflexes. We conclude that LBPP is not a suitable model for simulated weightlessness in humans.

In this study, we identified the neurons within nucleus tractus solitarius (nTS) activated by stimulation of airway sensory systems and examined the expression of AMPA receptor subtype(s) by these cells. We also investigated the possible involvement of endogenously released glutamate and AMPA receptors in the transmission of excitatory inputs from the sensory system of the respiratory tract to the neurons of the nTS. In these experiments we used: (1) immunodetection of c-fos encoded protein (cFos) expression to identify the nTS neurons activated by the stimulation of the airway sensory system; (2) receptor immunochemistry and confocal microscopy to determine the receptor(s) expressed by activated nTS neurons; (3) microdialysis to measure glutamate release, and (4) physiological measurements to examine the effects of selective receptor blockers, and thereby define the role of the glutamate and AMPA glutamatergic receptor subtype(s) in reflexly induced airway constriction. The results showed that activation of airway sensory receptors, by inhalation of aerosolized histamine or capsaicin, induced cFos expression in a subset of nTS neurons that also expressed the AMPA subtype of glutamate receptors. Furthermore, activation of sensory bronchoconstrictive receptors induced glutamate release within nTS, and blockade of the AMPA receptor subtype within nTS inhibited reflexly increased cholinergic outflow to the airways. These data indicate for the first time that glutamate and AMPA receptor signaling pathways are involved in the transmission of afferent inputs from the airways to the nTS, and in mediating reflex airway constriction.

The present study was designed to examine the vasodilator mechanisms elicited by electrical stimulation of trigeminal ganglion (TG) in cat lower lip of the cats. When vago-sympathectomized cats were fixed into a stereotaxic frame by means of ear-bars, etc., the lip blood flow (LBF) increase evoked by lingual nerve (LN) stimulation (parasympathetic reflex response) was almost abolished in 15 out of 34 animals, but unaffected in the other 19. With the animal in the stereotaxic frame, electrical stimulation at sites within the TG evoked an LBF increase whether or not the LN stimulation-induced reflex response was intact. However, hexamethonium abolished the TG stimulation-induced LBF increase in animals whose brainstem parasympathetic reflex was intact, but reduced it by only 50% in animals whose reflex was impaired. This difference was seen in all experiments in which the electrode site was within the TG proper, regardless of its exact position. Although the underlying mechanism is unclear, these data suggest that when the TG is stimulated the LBF increase is entirely mediated via the parasympathetic reflex mechanism in animals whose brainstem reflex is intact, and that an antidromic vasodilatation occurs only in animals whose brainstem parasympathetic reflex is impaired.

Immunoreactivity for galanin was examined in the sympathetic preganglionic neurons in the spinal cord, adrenal glands, sympathetic ganglia, and some sensory ganglia of the filefish Stephanolepis cirrhifer. Galanin-immunoreactive neurons were found only in the rostral part, but not in the caudal part of the central autonomic nucleus (a column of sympathetic preganglionic neurons of teleosts). Many galanin-immunoreactive nerve terminals were found in contact with neurons in the celiac ganglia and the cranial sympathetic ganglia on both sides of the body. Most neurons encircled by galanin-immunoreactive nerve fibers were negative for tyrosine hydroxylase. Galanin-immunoreactive nerve fibers were very sparse in the spinal sympathetic paravertebral ganglia. No galanin-immunoreactive nerve fibers were found in the adrenal glands. No sensory neurons of the trigeminal, vagal, or spinal dorsal root ganglia were positive for galanin-immunoreactivity. These results suggest that galanin-immunoreactive sympathetic preganglionic neurons have distinct segmental localization and might project specifically to a population of non-adrenergic sympathetic postganglionic neurons in the celiac and cranial sympathetic ganglia.