Electrophysiological and morphological classification of myenteric neurons in the proximal colon of the guinea-pig

Messenger, J. P.; Bornstein, Joel C.; Furness, John B.

doi:10.1016/0306-4522(94)90217-8

Cited by 53 publications

(67 citation statements)

References 57 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Although we might have missed fast inputs because it was not possible to stimulate all the fibres connecting the ganglia which contained the impaled neurone, our observation was in agreement with previous studies showing that myenteric AH neurones in the small intestine (Bornstein et al 1991;Kunze et al 1993) and in the proximal colon (Messenger et al 1994) did not receive fEPSPs. However, it has to be noted that some studies have reported fEPSPs in AH neurones in the small (see Wood, 1994) and large (Wade & Wood, 1988;Tamura & Wood, 1989) intestine.…”

Section: Pharmacology Of the Sepspsupporting

confidence: 92%

“…It has been shown that enteric neurones are involved in the response of the gut to SCFAs (Yajima, 1985;Diener et al 1996). AH neurones occur in different regions of the gut, namely in the antrum (Tack & Wood, 1992), the duodenum and ileum (Nishi & North, 1973;Hirst et al 1974), in the proximal colon (Messenger et al 1994), the distal colon (Wade & Wood, 1988) and the rectum of the guinea-pig (Tamura & Wood, 1989). However, their putative functions in these regions are unknown.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Characteristics of mucosally projecting myenteric neurones in the guinea‐pig proximal colon

Neunlist

Dobreva

Schemann

1999

The Journal of Physiology

View full text Add to dashboard Cite

Neural regulation of a variety of gastrointestinal functions is primarily achieved by the enteric nervous system which is embedded within the gastrointestinal wall. It is usually formed from two major plexus: the myenteric plexus located between the circular and the longitudinal muscle layer and the submucosal plexus situated between the submucosa and the mucosa (for review, see Wood, 1994). In the early part of the 1970s, the first attempt to classify enteric neurones was made using extracellular recording techniques (Wood, 1970). Nishi & North (1973) and Hirst et al. (1974) then used intracellular microelectrode techniques to determine the electrophysiological characteristics of myenteric neurones in the guinea-pig small intestine. Although their classification schemes did not recover exactly the same neuronal populations, two major groups of neurones were revealed. Following the classification of Hirst et al. (1974), S neurones (for synaptically driven) and AH neurones (named after the characteristic long-lasting membrane potential hyperpolarization following the action potential) made up the two populations. Further studies by Wood and his collaborators revealed the presence of different classes of myenteric neurones depending on the region of the gut studied (Wood, 1994). Additionally, enteric neurones may be subdivided into neurochemically distinct populations (Costa et al. 1996), whose number exceeds the broadly defined electrophysiological classes. The use of intracellular injection of biocytin or neurobiotin allowed the morphology of electrophysiologically classified neurones to be determined. AH neurones were extensively studied in the ileum (for review, see Furness et al. 1998) where they were shown to have morphological characteristics of multipolar Dogiel type II neurones with most processes projecting in the circumferential direction (Iyer et al. 1988;Bornstein et al. 1991). Neuronal tracing methods showed

show abstract

Section: Pharmacology Of the Sepspsupporting

confidence: 92%

mentioning

confidence: 99%

Characteristics of mucosally projecting myenteric neurones in the guinea‐pig proximal colon

Neunlist

Dobreva

Schemann

1999

The Journal of Physiology

View full text Add to dashboard Cite

show abstract

“…In a recent study, children suspected of having HD were submitted to rectal suction and there were inadequate procedures leading to repeated biopsies in 6% of patients. 21 Nerve cell bodies in both submucosa and myenteric ganglia of guinea pig 22,23 and in the human gastrointestinal tract are immunopositive for calretinin, a calcium-binding protein. 24 Recently, it has been suggested that calretinin might be more accurate than acetylcholinesterase in detecting aganglionosis 18 in a small series of rectal biopsy.…”

Section: Discussionmentioning

confidence: 99%

Calretinin immunohistochemistry: a simple and efficient tool to diagnose Hirschsprung disease

et al. 2009

View full text Add to dashboard Cite

Diagnosis of Hirschsprung disease (HD) is quite entirely based on the histopathological analysis of suction rectal biopsies. This hematoxylin and eosin approach has some limitations, despite the help of acetylcholinesterase staining. The aim of this study was to assess the diagnostic value of calretinin immunochemistry as a simple and reliable method in the diagnosis of HD. A total of 131 initial rectal biopsies carried out for suspicion of HD in children were retrieved, and calretinin immunohistochemistry was carried out on paraffin-embedded biopsies. Diagnosis of HD was made when no staining was observed. The results were statistically analyzed in comparison with our standard method (histology and acetylcholinesterase staining). 130 biopsies were accurately diagnosed on the basis of the positivity or negativity of calretinin staining. The senior pathologists diagnosed all cases of HD with no false positives. Furthermore, 12 additional cases initially considered as doubtful for HD using the standard method, were accurately diagnosed using calretinin immunohistochemistry. The false negative was a case of HD with a calretinin-positive biopsy. We also demonstrate the ease of calretinin interpretation compared with acetylcholinesterase for the junior pathologist. Calretinin immunohistochemistry overcomes most of the difficulties encountered using the combination of histology and acetylcholinesterase staining, and detects almost all cases of HD with confidence, with no false positives. Thus, we demonstrate that calretinin is superior to acetylcholinesterase to complete histology and could advantageously substitute for acetylcholinesterase. Modern Pathology ( The diagnosis of Hirschsprung disease (HD) is based on a combination of clinical features, radiological appearance of the bowel and histological features on suction rectal biopsies, 1,2 that is, aganglionosis and abnormally large nerves. In practice, a definite diagnosis of HD, leading to surgical treatment, is quite entirely based on histological results. 3,4 Several efficient approaches have been devised to assess the diagnosis of HD using a combination of standard histology and histochemistry. Standard histology obtained from rectal suction biopsies that sample mucosa and underlying submucosa, demonstrating rectal aganglionosis, requires the analysis of 100 or more histological sections to ensure good specificity, and is therefore time consuming. Moreover, difficulties in analysis may arise in several situations: (1) when the site of biopsy is too distal, because of the physiological paucity of ganglion cells; (2) when the sample is too superficial with not enough submucosa; and (3) when there is difficulty in identifying ganglion cells with confidence, particularly in neonates.For these reasons, standard histology is frequently supplemented with acetylcholinesterase histochemistry. 5,6 This technique, showing staining of extrinsic nerve fibers, provides quick results but requires frozen tissue samples. The last reports show good specificity of an abnormal ac...

show abstract

“…In the present study, we used the same classification scheme used to describe neurons in the guinea pig small intestine, because, as in the small intestine, there are two primary types, S or AH, of spiking neurons in the myenteric plexus of the colon (35,37,49). The most important criteria for identifying a given cell as an AH neuron were the presence or absence of a shoulder on the repolarizing phase of the action potential, its morphology, and the duration of the prolonged afterhyperpolarization (usually lasting seconds).…”

Section: Classification Of Impaled Neuronsmentioning

confidence: 99%

Effects of PGE₂ in guinea pig colonic myenteric ganglia

Manning

Sharkey

Mawe

2002

American Journal of Physiology-Gastrointestinal and Liver Physi

View full text Add to dashboard Cite

is a proinflammatory mediator that can influence many cell types. This study was conducted to determine whether PGE2 alters the electrical activity of distal colonic myenteric neurons, because colitis is typically associated with altered motility and changes in neural signaling may be involved. The electrical properties of intact myenteric neurons were evaluated with intracellular microelectrodes. Acute application of PGE 2 elicited a prolonged depolarization in both AH and S neurons with little effect on input resistance or electrical excitability. PGE 2 effects were suppressed by tetrodotoxin (TTX) or neurokinin (NK) receptor antagonists, indicating that PGE 2 acts directly and indirectly to depolarize colonic neurons. PGE 2-evoked depolarization was concentration dependent (ϳ3 M EC 50) and was attenuated by the E prostanoid (EP)1/2 receptor antagonist, AH-6809. When preparations were maintained for 48 h in the presence of the stable PGE 2 analog PGE2-ethanolamide (10 M), neurons exhibited a significant membrane depolarization and enhanced excitability. These results suggest that PGE 2 can play a role in altered motility in colitis by evoking changes in the electrical properties of myenteric neurons. motility; inflammation; colitis; innervation; enteric nervous system THE NERVOUS SYSTEM OF THE bowel, which is known as the enteric nervous system (ENS) regulates visceromotor, secretomotor, and vasomotor activities in the wall of the intestines. Given that much of the morbidity associated with inflammatory bowel disease is caused by disordered gastrointestinal motor function and that colonic smooth muscle function is regulated by the ENS, it is quite possible that alterations in the excitability of the enteric neurons contribute to intestinal dysmotility. A variety of immune-mediated inflammatory disorders exist, including Crohn's disease and ulcerative colitis, and dysmotility, hypersecretion, and enhanced perception of pain are common features (17,22,23,46). It is now clear that cutaneous and visceral inflammations lead to enhanced excitability of extrinsic primary afferent neurons and altered reflex activity (5,8,14,48). Changes may also occur in the afferent components of intrinsic enteric neural circuitry, and such changes could contribute to altered motor reflex activity in the inflamed bowel.In guinea pig bowel, it is possible to identify the functional role of a given neuron on the basis of consensus knowledge regarding the electrical, morphological, chemical coding, and axonal projection patterns of these cells. For example, a class of cells known as AH neurons, on the basis of electrical properties, functions as the afferent limb of the peristaltic reflex circuit (19) and is considered to have roles as intrinsic primary afferent neurons and interneurons (for review, see Ref. 30). These cells have a Dogiel type II morphology (multiple processes) and extend projections to other ganglia and to the lamina propria (7,34,40,42), where they could respond to stimuli originating at the mucosal surface. Therefor...

show abstract

Electrophysiological and morphological classification of myenteric neurons in the proximal colon of the guinea-pig

Cited by 53 publications

References 57 publications

Characteristics of mucosally projecting myenteric neurones in the guinea‐pig proximal colon

Characteristics of mucosally projecting myenteric neurones in the guinea‐pig proximal colon

Calretinin immunohistochemistry: a simple and efficient tool to diagnose Hirschsprung disease

Effects of PGE₂ in guinea pig colonic myenteric ganglia

Contact Info

Product

Resources

About

Electrophysiological and morphological classification of myenteric neurons in the proximal colon of the guinea-pig

Cited by 53 publications

References 57 publications

Characteristics of mucosally projecting myenteric neurones in the guinea‐pig proximal colon

Characteristics of mucosally projecting myenteric neurones in the guinea‐pig proximal colon

Calretinin immunohistochemistry: a simple and efficient tool to diagnose Hirschsprung disease

Effects of PGE2 in guinea pig colonic myenteric ganglia

Contact Info

Product

Resources

About

Effects of PGE₂ in guinea pig colonic myenteric ganglia