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Query: EC:3.1.1.7 (acetylcholinesterase)
 28,390 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Serum cholinesterase (E.C. 3.1.1.8) was assayed with succinylcholine as a substrate. The reaction was coupled with choline oxidase and peroxidase in the presence of 4-aminoantipyrine and phenol to produce a red quinone dye that was measured spectrophotometrically. The method requires 25 microliter of sample in a total volume of 1.0 ml. The mean activity for 35 adults of the usual genotype was 74.4 +/- 28 U/l (range 24-125 U/l). Succinylcholine-sensitive individuals had activities below 18 U/l. The same serum samples also were assayed with propionylthiocholine as a substrate. Activities with the two substrates showed a coefficient of correlation of 0.980 (n = 68). However, the method using propionylthiocholine showed more overlap between the activities of succinylcholine-sensitive and insensitive individuals. Assay with succinylcholine thus may offer a more effective method of screening for sensitive individuals, since some escape detection by conventional genotyping with dibucaine and fluoride.
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PMID:Assay of serum cholinesterase with succinylcholine and propionylthiocholine as substrates. 388 94

Embryonic neuroblasts of Drosophila are undifferentiated precursor cells that give rise to the central nervous system. Centrifugal elutriation has been employed to fractionate embryonic cells on the basis of size. A fraction of large cells was found to be greatly enriched for neuroblasts, whereas mesodermal precursor cells were completely excluded. This allowed a second step of purification, based upon adhesion to glass, to provide virtually pure cultures of neural cells. The cells in these cultures had the properties of neurons of the Drosophila CNS: They gave rise to ganglion-like clusters from which neurites extended on the culture substrate, and they expressed the enzyme, acetylcholinesterase, and the cell surface antigens recognized by antisera raised against horseradish peroxidase. The production of large-scale neuronal cell cultures will be useful for immunological and molecular studies of neural cell differentiation.
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PMID:Differentiation of primary embryonic neuroblasts in purified neural cell cultures from Drosophila. 388 53

The location of brainstem neurons which mediate the stapedius reflex was identified by injecting horseradish peroxidase into the stapedius muscle of squirrel monkeys and bush babies. Retrogradely labeled neurons, arranged in a one- to three-cell column, were found medial to the main facial motor nucleus in squirrel monkeys and ventral to it in bush babies. Nissl, protargol, and acetylcholinesterase stains were subsequently used to identify and describe this unique column of cells. It was found that staining characteristics, as well as shape, size, and location, distinguish stapedius muscle motoneurons from closely associated cell groups. Furthermore, stapedius muscle motoneurons are morphologically similar to periolivary cells and morphologically dissimilar to cells within the facial motor nucleus.
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PMID:Identification of stapedius muscle motoneurons in squirrel monkey and bush baby. 396 39

The organization of cholinergic inputs to cat striate cortex (area 17) was studied by using a histochemical stain for acetylcholinesterase (AChE). Axons were labelled in all layers of the striate cortex, with distinct plexuses occurring in layer I, lower layer III, layer IVc, and layer VI. In addition to the stained axons, a population of layer V pyramidal cells was intensely AChE-positive. Surgical undercutting eliminated virtually all of the AChE-positive axons in the striate cortex, thus indicating that this innervation arises entirely from an extrinsic source in the cat. To identify this source, cell groups projecting to area 17 were retrogradely labelled with horseradish peroxidase. Cell groups labelled with horseradish peroxidase that were also intensely AChE-positive were considered as possible candidates for providing the cholinergic input to the striate cortex. These included the basal forebrain, several intralaminar nuclei, and the lateral geniculate nucleus. Kainate lesions were then made in each of these structures to assess their individual contributions to the cortical AChE pattern. Cortical AChE was depleted only after lesions of the basal forebrain, suggesting that this is the sole source of AChE-positive axons in area 17. Because the cortically projecting cells in this region have been shown to contain choline acetyltransferase in a number of species, we postulate that the AChE-positive fibers we describe in the cat striate cortex are in fact cholinergic.
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PMID:An investigation of cholinergic circuitry in cat striate cortex using acetylcholinesterase histochemistry. 398 93

The patterns of distribution of frontotectal and nigrotectal fibers were studied with the anterograde horseradish peroxidase method in the cat. Direct serial-section comparisons were made between the afferent-fiber patterns and the compartmentalized arrangements of acetylcholinesterase staining within the intermediate and deep collicular layers. Many of the patches of high acetylcholinesterase activity in the intermediate gray layer proved to be zones in which labeled frontotectal and nigrotectal fibers converged. These acetylcholinesterase-rich patches may thus represent sites at which functional influences from the basal ganglia and frontal cortex are coordinated. In the deeper tiers of the intermediate gray layer and layers ventral to it, there were also zones of heightened and diminished acetylcholinesterase staining. Much of this histochemical patterning was reflected in the arrangement of fibers labeled by large rostromedial frontal injections, but these deeper tiers were not strongly labeled after more lateral frontal injections or after injections placed in the substantia nigra. The deeper parts of the acetylcholinesterase-positive gridwork in the superior colliculus are thus distinct from its upper tier of acetylcholinesterase-positive patches. We conclude that the compartmentalized patterning of dense acetylcholinesterase staining in the intermediate and deep collicular layers represents a mosaic architecture to which collicular afferent circuitry is tightly related. This gridwork may serve to set up functional domains within which different aspects of collicular processing are accommodated.
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PMID:Convergence of afferents from frontal cortex and substantia nigra onto acetylcholinesterase-rich patches of the cat's superior colliculus. 399 Sep 54

The tibialis anterior and extensor digitorum longus muscles of the rat were reduced in size either by crushing the sciatic nerve or by removing part of the muscle tissue during the first postnatal week. Four to 6 weeks later the number and size of the motoneurones supplying these muscles were assessed using retrograde transport of horseradish peroxidase. The pattern of synaptic connections in the muscles supplied by these motoneurones was examined 3-46 weeks after the initial operation using a combined silver cholinesterase stain. The number of labelled motoneurones was not reduced after nerve crush but was reduced to some extent after partial muscle removal. The distribution of motoneurone sizes, however, was altered by both procedures in that the largest motoneurones became smaller. In the muscle both procedures affected synaptic organization. In the case of sciatic nerve crush at 5-6 days the incidence of muscle fibres with more than one endplate and endplates contacted by more than one axon terminal was higher than in normal adult muscles. When part of the muscle was removed, the predominant feature was the persistence of a high incidence of free sprouting nerve fibres. We therefore conclude that reduction of the peripheral field during the postnatal period does affect the development of some motoneurones.
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PMID:The effect of reducing the peripheral field on motoneurone development in the rat. 399 31

The dorsal tegmental pathway in the rat brain has been studied using acetylcholinesterase (AChe) staining alone, after lesions, and combined with the horseradish-peroxidase (HRP) tracing method. This paper characterises in photographs, diagrams and text the origins, form, extent and relations of its visible AChe-staining fibres in 3 planes. This record should provide a template for further investigations. The pathway largely takes origin from ChAT-containing pedunculopontine (PPTg) and laterodorsal (LDT) nuclei; some non-cholinergic cell groups may also contribute, notably locus coeruleus (LC). It takes the form of a horizontally disposed fan which radiates from the pontomesencephalic area to the forebrain. Its lateral portion is bunched and consists mainly of cholinergic fibres whereas the cholinergic status of its fully unfurled intermediate and partly unfurled medial contingents (which mainly accompany the central tegmental tract) is more doubtful. The changing form and relations of PPTg and LDT are adumbrated including that of the microcellular nucleus (MI) to the former and of Barrington's detrusor nucleus (B) which is unstained, to the latter. Functional overlapping between non-cholinergic and cholinergic nuclei in the peribrachial region are noted and some correlations adduced.
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PMID:A photographic perspective on the origins, form, course and relations of the acetylcholinesterase-containing fibres of the dorsal tegmental pathway in the rat brain. 405 23

The distribution of cholinoceptive neurons in the lower brainstem of the rat was investigated by means of a histochemical method for specific acetylcholinesterase. Nicotinoceptive neurons were characterized using an alpha-bungarotoxin-horseradish peroxidase conjugate for the detection of nicotinic acetylcholine receptors. For the first time a nearly complete mapping of the location of cholinoceptive (nicotinoceptive) neurons of the lower brainstem was achieved. Special attention was focused on the organization of the cholinoceptive neuronal matrix of the ventral surface of the medulla, where regulative centers for vasomotor and respiratory control are located.
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PMID:Mapping of cholinoceptive(nicotinoceptive)neurons in the lower brainstem: with special reference to the ventral surface of the medulla. 406 86

Mouse neuroblastoma cells (clone neuro-2A) in the undifferentiated and "differentiated" form were compared by light and electron microscopy. "Cytodifferentiation" was induced in monolayer cultures by the addition of dibutyryl-cyclic AMP. The pattern of concanavalin A binding sites was studied after coupling with horseradish peroxidase. The following major differences were observed. The differentiated cells are characterized by numerous and long neurites, aggregation of ribosomes into polysomes, an extensive network of neurofilaments and microtubules, many dense-core neurosecretory-like vesicles, a discontinuous pattern of concanavalin A binding sites on the plasma membrane, and an increase of the specific activities of acetylcholinesterase, choline acetylase and tyrosine hydroxylase. In contrast, the undifferentiated cells grown in suspension culture lack neurites, contain dispersed ribosomes, infrequent neurofilaments and microtubules and dense-core neurosecretory-like vesicles, and exhibit a continuous pattern of concanavalin A binding sites. In addition, the specific activities of the above mentioned enzymes are significantly lower.
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PMID:The undifferentiated and extended forms of C1300 murine neuroblastoma. An ultrastructural study and detection of concanavalin A binding sites on the plasma membrane. 415 21

Effect of estradiol propionate on activity of seven enzymes from rabbit uterus was studied. Simultaneously with the known estrogen-induced enzymes, activity of some other enzymes from uterus cells (tyrosine transaminase, acetylcholinesterase, butyrylcholinesterase) was also studied. The hormone induced all the enzymes studied except of butyrylcholinesterase. After induction with the estrogen a new isoenzyme fraction was found in peroxidase: at the same time, content of isoenzymes of lactate dehydrogenase, tyrosine transaminase and acetylcholinesterase was increased.
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PMID:[Induction of various enzymes in the rabbit uterus with estradiol]. 613 Jun 52


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