Lectin histochemical studies on the olfactory epithelium and vomeronasal organ in the Japanese striped snake,Elaphe quadrivirgata

The olfactory epithelium and the vomeronasal organ of the Japanese striped snake were examined by lectin histochemistry. Of the 21 lectins used in the study, all lectins except succinylated‐wheat germ agglutinin (s‐WGA) showed similar binding patterns in the vomeronasal receptor cells and the olfactory receptor cells with varying intensities. The binding patterns of s‐WGA varied among individuals in the vomeronasal and olfactory receptor cells, respectively. Four lectins, Bandeiraea simplicifolia lectin‐II (BSL‐II), Dolichos biflorus agglutinin (DBA), Sophora japonica agglutinin (SJA), and Erythrina cristagalli lectin (ECL) stained secretory granules and the organelles in the olfactory supporting cells and did not stain them in the vomeronasal supporting cells. These results suggest that the glycoconjugate moieties are similar in the vomeronasal and olfactory receptor cells of the Japanese striped snake. J. Morphol., 2010. © 2010 Wiley‐Liss, Inc.     

Lectin histochemical study of lipopigments with special regard to neuronal ceroid-lipofuscinosis

Summary Concanavalin A (ConA) binding to lipopigments (LPs) of the lipofuscin type was proved to be due to the high content of mannose. The nature of the mannose bearing compound was twofold. One part was soluble in modified chloroform-methanol-water mixture (10:10:3) corresponding possibly to the oligosaccharyl diphosphodolichol (oligo-PP-Dol) described to be increased in LPs especially of inherited types. The second part, most probably a glycoprotein (GP), was entirely resistant to various extraction procedures. The ratio of the two components varied. The deposition of the typical lipofuscin (age pigment) was dominated by the GP component. Its amount was greatest in neurolipofuscin (especially in the olivary nucleus) and in the myocardium but very little in hepatocytic lipofuscin. In human neuronal ceroid lipofuscinoses (of early juvenile, and juvenile types) both components were found in large quantities in the storage granules of the affected neurons. The protein type variant of the storage material (Elleder 1978) displayed the highest degree of lipid-bound mannose accumulation, the GP component being extremely low or entirely absent. In the late infantile, infantile and Kufs variants studied in paraffin sections only, the GP component was detetable, too as in the case of the secondary neuronal LP in mucopolysaccharidoses and gangliosidoses. In the dog model of NCL lipid bound mannose clearly predominated, the GP component being concentrated in the cytoplasm and on the periphery od some storage granules. The nature of the GP component, a new finding of LP analysis, is discussed. The metabolic relationship between the two components is uncertain. Neither could be identified as the component resposible for autofluorescence. However, both are most probably responsible for PAS positivity of lipofuscins. The ceroid-type histiocytic LP did not display any detectable increase in any of the mannose bearing components.Abbreviations NCL neuronal ceroid lipofuscinosis - HNCL human NCL - CNCL canine NCL - ONCL ovine NCL - LP lipopigment - GP glycoprotein     

Lectin histochemical study on the infraorbital gland of the Japanese serow (Capricornis crispus)

Histology and lectin histochemistry were performed in the infraorbital gland of the Japanese serow. The gland is composed of glandular tissues and a pouch filled with the secretion. The tissues consist of an inner layer of sebaceous glands and an outer layer of apocrine glands. The male sebaceous layer is made up of the ordinary type, whereas the female's layer consists of the ordinary and modified types. In the apocrine gland stained with Arachis hypogaea (PNA), nine different patterns of glandular tubules were distinguished on the basis of staining of the cytoplasm, the Golgi area of secretory cells and secretion. Secretory modes of apocrine secretion and exocytosis were included in these stainings. Myoepithelial cells stained constantly with Glycine max (SBA) except when only the Golgi area of secretory cells was positive. The modified sebaceous gland was stained with PNA, SBA, Ricinus communis I (RCA), Triticum vulgaris (WGA), Canavalia ensiformis (Con A) and Ulex europaeus I (UEA), while the ordinary type was positive in PNA, RCA, SBA, WGA and Con A. The secretion in the pouch was stained with PNA, RCA, SBA, Dolichos biflorus (DBA), WGA and Con A. These findings suggest that the modified sebaceous gland contains large amounts of glycoconjugates and the apocrine gland shows a cyclic secretory process of apocrine secretion and exocytosis.     

Lectin histochemical identification of carbohydrate moieties in opossum chemosensory systems during development,with special emphasis on VVA-identified subdivisions in the accessory olfactory bulb

The changes occurring in the testicular lamina propria (LP) of the seasonal breeder Octodon degus were analyzed. Four groups of animals were studied using electron microscopic procedures. The animals in group I were reproductively active, whereas those in groups II, III, and IV were in periods of recrudescence, regression, and resting, respectively. These changes, observed in animals maintained under laboratory lighting conditions, resembled those known to be elicited in feral populations by natural photoperiods. Testicular changes in each group were monitored by calculating the gonadosomatic and spermatogenetic indexes, and by obtaining averages of the diameter of the seminiferous tubules and the height of the seminiferous epithelium. The LP of group I animals consisted of a basal membrane formed by two to four lamellae, inner and outer acellular layers containing moderate numbers of collagenous fibrils, and single or double layers of smoothly contoured myoid cells encircled by a discontinuous lymphatic epithelium. The LP of group IV animals differed considerably from the LP of group I animals: The inner acellular layer was enlarged, and the basal membrane appeared composed of a variable number of lamellae with numerous folds and indentations. Myoid cells were very irregular in contour and enveloped by a well-developed surface coating. The LPs of animals in groups II and III possessed relatively similar characteristics, which appeared to be intermediate between those of groups I and IV. The significance of these morphological changes in the LP are discussed in relation to testicular changes induced by photoperiod and other normal or pathological processes. © 1995 Wiley-Liss, Inc.     

Lectin histochemical studies of mouse granulated metrial gland cells

A lectin histochemical study has been carried out on mouse granulated metrial gland cells, the major leucocyte population that differentiates in the uterine wall in pregnancy. The binding characteristics of 26 lectins were examined using light microscopical methods. Fourteen of the lectins, with affinities ranging through N-acetylgalactosamine, galactose, N-acetylglucosamine, mannose and sialic acid residues, bound to the cytoplasmic granules of granulated metrial gland cells, and each appeared to bind to the limiting membrane of the granules. The binding characteristics of three of these lectins (Wheat germ agglutinin, Concanavalin A and Helix pomatia agglutinin) were examined using electron microscopical methods. These showed a different binding pattern to the cytoplasmic granules of granulated metrial gland cells compared with that found using light microscopical methods, as they appeared to bind evenly across the granule's matrix. This binding pattern corresponds to the reactivity of the granule matrix in the periodic acid--Schiff technique. Six lectins bound to the cell membranes of granulated metrial gland cells. These included the E and L isoforms of Phaseolus vulgaris agglutinin, with affinities for complex carbohydrates, whose binding differences were related to the stage of differentiation of the granulated metrial gland cells. The lectin binding described presents additional markers of granulated metrial gland cells and tools for investigating carbohydrate moieties in the functional activities of granulated metrial gland cells This revised version was published online in November 2006 with corrections to the Cover Date.     

Lectin histochemical studies of mouse granulated metrial gland cells

A lectin histochemical study has been carried out on mouse granulated metrial gland cells, the major leucocyte population that differentiates in the uterine wall in pregnancy. The binding characteristics of 26 lectins were examined using light microscopical methods. Fourteen of the lectins, with affinities ranging through N-acetylgalactosamine, galactose, N-acetylglucosamine, mannose and sialic acid residues, bound to the cytoplasmic granules of granulated metrial gland cells, and each appeared to bind to the limiting membrane of the granules. The binding characteristics of three of these lectins (Wheat germ agglutinin, Concanavalin A and Helix pomatia agglutinin) were examined using electron microscopical methods. These showed a different binding pattern to the cytoplasmic granules of granulated metrial gland cells compared with that found using light microscopical methods, as they appeared to bind evenly across the granule's matrix. This binding pattern corresponds to the reactivity of the granule matrix in the periodic acid--Schiff technique. Six lectins bound to the cell membranes of granulated metrial gland cells. These included the E and L isoforms of Phaseolus vulgaris agglutinin, with affinities for complex carbohydrates, whose binding differences were related to the stage of differentiation of the granulated metrial gland cells. The lectin binding described presents additional markers of granulated metrial gland cells and tools for investigating carbohydrate moieties in the functional activities of granulated metrial gland cells     

Lectin histochemical localization of galactose,N-acetylgalactosamine,and N-acetylglucosamine in glycoconjugates of the rat vomeronasal organ,with comparison to the olfactory and septal mucosae

The localization of -D-galactose, N-acetyl-D-galactosamine, and N-acetyl-D-glucosamine sugar residues of glycoconjugates in the vomeronasal organ, olfactory mucosa, and septal organ in the nasal mucosae of rats was investigated using lectinohistochemical techniques combined with bright-field, epifluorescence, and confocal laser scanning microscopy. Glycoconjugates in the mucomicrovillar complex of the vomeronasal organ contained all the sugar residues investigated, whereas glycoconjugates in the mucociliary complex of the olfactory mucosa and septal organ contained only N-acetyl-D-glucosamine. Vomeronasal receptor neurons expressed glycoconjugates with terminal -D-galactose and -N-acetyl-D-galactosamine, and N-acetyl-D-glucosamine residues, whereas olfactory and septal receptor neurons expressed glycoconjugates with only N-acetyl-D-glucosamine residues. Secretory granules of glands of the vomeronasal organ contained glycoconjugates with terminal -D-galactose and N-acetyl-D-galactosamine, and N-acetyl-D-glucosamine, whereas those of the Bowman's glands and glands of septal organ contained glycoconjugates with only internal N-acetyl-D-glucosamine residues. The results demonstrate that the glycoconjugates expressed by vomeronasal receptor neurons and glands contain terminal -D-galactose and -N-acetyl-D-galactosamine sugar residues that are not expressed by analogous cells in the olfactory mucosa and septal organ.     

Identification of carbonic anhydrase activity in bullfrog olfactory receptor neurons: histochemical localization and role in CO2 chemoreception

The objectives of this study were to determine: (1) the frequency and distribution of carbonic anhydrase (CA) activity in the bullfrog nasal cavities, and (2)␣whether inhibition of nasal CA affects the olfactory receptor response to CO₂ or other odorants. It was found, using Hansson's staining technique, that some olfactory receptor neurons exhibited CA activity and that these CA-positive receptors were distributed throughout the nasal cavity with peak densities in the dorsal and ventral sensory epithelial regions. To test for the role of CA in olfactory transduction, electro-olfactograms (EOGs) were recorded from the surface of the ventral sensory epithelium in response to 2-s pulses of 5% CO₂ and amyl acetate before and after topical CA inhibition with acetazolamide (10⁻³mol · l⁻¹). In 52 bullfrogs, 1222 sites on the ventral epithelium were tested resulting in 23 locations that exhibited a response to 5% CO₂. Inhibition of CA caused an immediate 65% reduction in the EOG response to CO₂ while the response to amyl acetate was not affected. These results, along with the histochemical localization of CA in some olfactory receptor neurons, indicate that CA plays a role in the detection of CO₂ in frog olfactory neurons and that only a small population of olfactory receptor neurons are CO₂ sensitive. Accepted: 31 July 1997     

Lectin binding sites in normal and phenobarbitale/halothane treated rat liver. A histochemical study

The content of carbohydrate residues of both normal and phenobarbitale-halothane-hypoxia exposed rat liver has been examined by means of lectin histochemistry. Eight biotinylated lectins specific to galactose, N-acetyl-galactosamine, N-acetyl-glucosamine, fucose and mannose were applied to paraffin sections of rat liver at light microscopic level. The most distinct binding was observed at the structures of the "perisinusoidal functional unit": Kupffer cells are bound by S-WGA, SBA and PNA. Bile canaliculi display binding sites for RCA I and WGA. Cytoplasm of hepatocytes appears lectin-negative, except for PSA. The enhanced reaction of S-WGA, PNA and SBA after the preincubation of the sections with neuraminidase indicates the occurrence of sialic acid in Kupffer cells. The phenobarbitale-halothane-hypoxia exposed rat liver shows centrolobular degeneration of hepatocytes with a diminished amount of hepatocyte and Kupffer cells as well. The lectin binding pattern of sinusoidal walls, membranes of hepatocytes and bile canaliculi remains the same compared to that of normal rat liver. This finding suggests that at least the carbohydrate content of membranes in the liver resists severe destruction under phenobarbitale-halothane-hypoxia. It is assumed that there exists a connection between intact carbohydrate residues and the regeneration of liver parenchyma.     

Lectin histochemical study of lipopigments with special regard to neuronal ceroid-lipofuscinosis. Results with concanavalin A

Concanavalin A (ConA) binding to lipopigments (LPs) of the lipofuscin type was proved to be due to the high content of mannose. The nature of the mannose bearing compound was twofold. One part was soluble in modified chloroform-methanol-water mixture (10:10:3) corresponding possibly to the oligosaccharyl diphosphodolichol (oligo-PP-Dol) described to be increased in LPs especially of inherited types. The second part, most probably a glycoprotein (GP), was entirely resistant to various extraction procedures. The ratio of the two components varied. The deposition of the typical lipofuscin (age pigment) was dominated by the GP component. Its amount was greatest in neurolipofuscin (especially in the olivary nucleus) and in the myocardium but very little in hepatocytic lipofuscin. In human neuronal ceroid lipofuscinoses (of early juvenile, and juvenile types) both components were found in large quantities in the storage granules of the affected neurons. The "protein type variant" of the storage material (Elleder 1978) displayed the highest degree of lipid-bound mannose accumulation, the GP component being extremely low or entirely absent. In the late infantile, infantile and Kufs variants studied in paraffin sections only, the GP component was detectable, too as in the case of the secondary neuronal LP in mucopolysaccharidoses and gangliosidoses. In the dog model of NCL lipid bound mannose clearly predominated, the GP component being concentrated in the cytoplasm and on the periphery od some storage granules. The nature of the GP component, a new finding of LP analysis, is discussed. The metabolic relationship between the two components is uncertain. Neither could be identified as the component resposible for autofluorescence.(ABSTRACT TRUNCATED AT 250 WORDS)     

Response patterns of single neurons in the tortoise olfactory epithelium and olfactory bulb

The responses to odor stimulation of 40 single units in the olfactory mucosa and of 18 units in the olfactory bulb of the tortoise (Gopherus polyphemus) were recorded with indium-filled, Pt-black-tipped microelectrodes. The test battery consisted of 27 odorants which were proved effective by recording from small bundles of olfactory nerve. Two concentrations of each odorant were employed. These values were adjusted for response magnitudes equal to those for amyl acetate at –2.5 and –3.5 log concentration in olfactory twig recording. Varying concentrations were generated by an injection-type olfactometer. The mucosal responses were exclusively facilitory with a peak frequency of 16 impulses/sec. 19 mucosal units responded to at least one odorant and each unit was sensitive to a limited number of odorants (1–15). The sensitivity pattern of each unit was highly individual, with no clear-cut types, either chemical or qualitative, emerging. Of the 18 olfactory bulb units sampled, all responded to at least one odorant. The maximum frequency observed during a response was 39 impulses/sec. The bulbar neurons can be classified into two types. There are neurons that respond exclusively with facilitation and others that respond with facilitation to some odorants and with inhibition to others. Qualitatively or chemically similar odorants did not generate similar patterns across bulbar units.     

Odour transduction in olfactory receptor neurons

The molecular mechanisms that control the binding of odorant to olfactory receptors and transduce this signal into membrane depolarization are reviewed. They are compared in vertebrates and insects for interspecific (allelochemicals) and intraspecific (pheromones) olfactory signals. Attempts to develop quantitative models of these multistage signalling networks are presented. Computational analysis of olfactory transduction is still in its infancy and appears as a promising area for future developments.     

Histochemical and immunocytochemical study of the migration of neurons from the rat olfactory placode

Immunocytochemical and histochemical methods have been used to describe the neuronal population migrating from the rat olfactory placode and to analyze the spatio-temporal evolution of this neuronal migration during development. Several neuronal markers, such as binding to the lectin Ulex europaeus (UEA I) and the presence of neuron-specific enolase (NSE), olfactory marker protein (OMP), and luteinizing hormone-releasing hormone (LHRH), have been tested in order to determine whether migrating neurons originate from both the medial and the lateral parts of the placode and whether they all express LHRH. Our data show that a large population of differentiated migrating neurons can be identified with an antibody against NSE from the 14th day of gestation and with UEA I one day later. Migrating neurons are closely associated with both the vomeronasal axon fascicles emerging from the medial pit and the olfactory axons originating from the lateral pit. However, the neuron migration from the lateral pit appears to be more discrete than that from the medial pit. No LHRH immunoreactivity has been detected among neurons migrating from the lateral pit. Some neurons accompanying the olfactory axon fascicles exhibit a high level of maturation as shown by their OMP-positivity. Numerous neurons positive for both NSE and UEA I have also been observed within the presumptive olfactory nerve layer in early embryonic stages.     

Coupling between sensory neurons in the olfactory epithelium

Coupling of olfactory sensory neurons (OSNs) in the olfactory epithelium of Necturus maculosus was demonstrated by dye-transfer with Lucifer yellow CH; however, the incidence of dye-transfer was low. Immunocytochemistry and Western blot analysis indicated that connexin 43, a gap junction channel subunit, was widely expressed by cells in the olfactory epithelium. Electrical coupling by presumptive gap junctions was assessed using electrophysiological recordings, heptanol block, tracer-uptake through hemi-junctions, and tracer-injection into tissue whole-mounts. Coupling, which involved pairs of OSNs only, was detected in approximately 3-10% of the OSN population; there was no evidence that OSNs were coupled into extended neural syncitia. These results suggest that coupling of OSNs by gap junctions is unlikely to have a general role in olfactory responses by mature (odor responsive) OSNs. Instead, the incidence of inter-neuronal coupling was small, similar to the fraction of immature OSNs, suggesting a possible role of gap junctions in the continual turnover and development of OSNs or possibly their senescence.     

Sugar residues of glycoconjugates in the olfactory epithelium of the human fetus: histochemical study using peroxidase-conjugated lectins]

The oligosaccharide content of glycoconjugates was studied at the olfactory epithelium of human fetuses ranging from 8 to 12 weeks of gestation by mean of peroxidase labelled lectins (DBA, PNA, WGA, SBA, ConA, LTA, UEA I). The main results demonstrated that: 1-The olfactory epithelium (olfactory cells, supporting cells and basal cells) was generally characterized by different amount of a-D-mannose, a-D-galactosamine, a-D-glucose, D-galactose-(beta 1-3)-N-acetyl-galactosamine, sialic acid and a-L-fucose. 2-At the 11th-12th week of gestation the largest amount of sugar residues was detected at the olfactory cells and at some basal cells. 3-At the 12th week of gestation, UEA I may be considered a specific marker of the olfactory cells in different stages of development.     

Respiratory modulation of olfactory neurons in the rodent brain

In this review we report data from freely breathing animals in an attempt to show how respiratory dynamics can influence bulbar and cortical activity. Relying on in vivo data as well as in vitro observations, we try to emphasize the multiple mechanisms that underlie this modulation, its multiple origins, and its possible functional role.     

Wheat germ agglutinin binding in rat primary sensory neurons: a histochemical study

Summary The binding of wheat germ agglutinin (WGA) to L5 dorsal root ganglion (DRG) cells in the rat was studied with the WGA-FITC conjugate. These cells were also examined with regard to overlap between WGA staining and choleragenoid-like immunoreactivity. The DRG cells showed varying intensity of the staining, which was confined to the cytoplasm. The majority of the small cells were heavily stained, whereas the large cells showed less or occasionally no staining. Lectin binding was observed along nerve fibres in the ganglion, and appeared to be localized to the Schwann cells and to the nodes of Ranvier. Strong staining was also observed in the area surrounding the ganglion cells and seemed to be confirned to the satellite cells. A subpopulation of the ganglion cells showed both WGA-staining and choleragenoid-like immunoreactivity. These results indicate a nonuniform affinity of WGA for different subpopulations of DRG neurons.