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Nerve Pathways (nerve + pathway)
Selected AbstractsMethods of gastric electrical stimulation and pacing: a review of their benefits and mechanisms of action in gastroparesis and obesityNEUROGASTROENTEROLOGY & MOTILITY, Issue 3 2009W. L. Hasler Abstract, Development of gastric electrical stimulation techniques for treatment of gastric dysmotility syndromes and obesity has been a long-standing goal of investigators and clinicians. Depending on stimulus parameters and sites of stimulation, such methods have a range of theoretical benefits including entrainment of intrinsic gastric electrical activity, eliciting propagating contractions and reducing symptomatology in patients with gastroparesis and reducing appetite and food intake in individuals with morbid obesity. Additionally, gastric stimulation parameters have extragastrointestinal effects including alteration of systemic hormonal and autonomic neural activity and modulation of afferent nerve pathways projecting to the central nervous system that may represent important mechanisms of action. Numerous case series and smaller numbers of controlled trials suggest clinical benefits in these two conditions, however better controlled trials are mandated to confirm their efficacy. Current research is focusing on novel stimulation methods to better control symptoms in gastroparesis and promote weight reduction in morbid obesity. [source] The cannabinoid CB2 receptor: a good friend in the gutNEUROGASTROENTEROLOGY & MOTILITY, Issue 9 2007A. A. Izzo Abstract, Mammalian tissues express the cannabinoid 1 (CB1) receptor and the cannabinoid 2 (CB2) receptor, the latter being involved in inflammation and pain. In somatic nerve pathways, the analgesic effects of CB2 agonism are well documented. Two papers published in the Journal have provided evidence that CB2 receptor activation inhibits visceral afferent nerve activity in rodents. These exciting findings are discussed in the context of recent data highlighting the emerging role of CB2 receptor as a critical target able to counteract hypermotility in pathophysiological states, gut inflammation and possibly colon cancer. [source] Investigating afferent nerve activity from the lower urinary tract: Highlighting some basic research techniques and clinical evaluation methods,,NEUROUROLOGY AND URODYNAMICS, Issue 1 2010Jean Jacques Wyndaele Abstract Aims To give a review of some basic research recording and clinical evaluations of bladder afferent nerves and the sensory information related to them. Methods Literature survey. Results Direct investigation of the afferent nerve pathways of the lower urinary tract (LUT) can be done in animal studies where potentials can be recorded and measured directly in the dorsal roots after laminectomy. Differentiation between A delta and C fibers is possible when conduction speed is determined. In humans afferent innervation can be studied clinically with determination of the sensation on sensation-related bladder diary, during cystometrical bladder filling, with local electrical stimulation. All need further study. Electrodiagnostic tests are further explored. Conclusions Both basic research and clinical evaluation of afferent nerves and sensory function in the LUT are possible. To find out how both relate to each other, and how this function can be evaluated, is the task to be done now. Neurourol. Urodynam. 29: 56,62, 2010. © 2009 Wiley-Liss, Inc. [source] Synchronization of enteric neuronal firing during the murine colonic MMCTHE JOURNAL OF PHYSIOLOGY, Issue 3 2005Nick J. Spencer DiI (1,1,didodecyl-3,3,3,,3,-tetramethylindocarbecyanine perchlorate) retrograde labelling and intracellular electrophysiological techniques were used to investigate the mechanisms underlying the generation of spontaneously occurring colonic migrating myoelectric complexes (colonic MMCs) in mice. In isolated, intact, whole colonic preparations, simultaneous intracellular electrical recordings were made from pairs of circular muscle (CM) cells during colonic MMC activity in the presence of nifedipine (1,2 ,m). During the intervals between colonic MMCs, spontaneous inhibitory junction potentials (IJPs) were always present. The amplitudes of spontaneous IJPs were highly variable (range 1,20 mV) and occurred asynchronously in the two CM cells, when separated by 1 mm in the longitudinal axis. Colonic MMCs occurred every 151 ± 7 s in the CM and consisted of a repetitive discharge of cholinergic rapid oscillations in membrane potential (range: 1,20 mV) that were superimposed on a slow membrane depolarization (mean amplitude: 9.6 ± 0.5 mV; half-duration: 25.9 ± 0.7 s). During the rising (depolarizing) phase of each colonic MMC, cholinergic rapid oscillations occurred simultaneously in both CM cells, even when the two electrodes were separated by up to 15 mm along the longitudinal axis of the colon. Smaller amplitude oscillations (< 5 mV) showed poor temporal correlation between two CM cells, even at short electrode separation distances (i.e. < 1 mm in the longitudinal axis). When the two electrodes were separated by 20 mm, all cholinergic rapid oscillations and IJPs in the CM (regardless of amplitude) were rarely, if ever, coordinated in time during the colonic MMC. Cholinergic rapid oscillations were blocked by atropine (1 ,m) or tetrodotoxin (1 ,m). Slow waves were never recorded from any CM cells. DiI labelling showed that the maximum projection length of CM motor neurones and interneurones along the bowel was 2.8 mm and 13 mm, respectively. When recordings were made adjacent to either oral or anal cut ends of the colon, the inhibitory or excitatory phases of the colonic MMC were absent, respectively. In summary, during the colonic MMC, cholinergic rapid oscillations of similar amplitudes occur simultaneously in two CM cells separated by large distances (up to 15 mm). As this distance was found to be far greater than the projection length of any single CM motor neurone, we suggest that the generation of each discrete cholinergic rapid oscillation represents a discreet cholinergic excitatory junction potential (EJP) that involves the synaptic activation of many cholinergic motor neurones simultaneously, by synchronous firing in many myenteric interneurones. Our data also suggest that ascending excitatory and descending inhibitory nerve pathways interact and reinforce each other. [source] Influence of alpha-adrenoceptor blockade on antigen- and propranolol-induced bronchoconstriction in guinea-pigs in vivoAUTONOMIC & AUTACOID PHARMACOLOGY, Issue 1 2000Y. Ishiura 1 Beta-adrenoceptor antagonists, such as propranolol, can provoke severe bronchoconstriction only in asthmatic subjects. Recently, we developed a guinea-pig model of propranolol-induced bronchoconstriction (PIB) and the purpose of this study was to investigate the role of alpha-adrenergic nerve pathways in this reaction. 2 Phentolamine administered after an antigen challenge did not inhibit PIB; however, its administration before the antigen challenge significantly inhibited the antigen-induced bronchoconstriction and also bronchoconstriction induced by methacholine inhalation. 3 We conclude that the alpha-adrenergic nerve system is not involved in the development of PIB following allergic reaction in our guinea-pig model. [source] | ||||||||||