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NCAM Expression (ncam + expression)
Selected AbstractsRegulation of hippocampal cell adhesion molecules NCAM and L1 by contextual fear conditioning is dependent upon time and stressor intensityEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 9 2000J. Joaquín Merino Abstract Cell adhesion molecules (CAMs) of the immunoglobulin superfamily, NCAM and L1, as well as the post-translational addition of ,-2,8-linked polysialic acid (PSA) homopolymers to NCAM (PSA,NCAM), have been implicated in the neural mechanisms underlying memory formation. Given that the degree of stress elicited by the training situation is one of the key factors that influence consolidation processes, this study questioned whether training rats under different stressor intensities (0.2, 0.4, or 1 mA shock intensity) in a contextual fear conditioning task might regulate subsequent expression of NCAM, PSA,NCAM and L1 in the hippocampus, as evaluated immediately after testing rats for conditioning at 12 and 24 h after training. Behavioural inhibition (evaluated as a ,freezing' index) at testing and post-testing plasma corticosterone levels were also assessed. The results showed that 12 h post-training, conditioned animals displayed reduced NCAM, but increased L1, expression. At this time point, the group trained at the highest shock intensity (1 mA) also presented decreased PSA,NCAM expression. Analyses performed 24 h post-training indicated that the 1 mA group exhibited increased NCAM and L1 expression, but decreased expression of PSA,NCAM levels. In addition, L1 values that presented a shock intensity-dependent U-shaped pattern were also increased in the group trained at the lowest shock condition (0.2 mA) and remained unchanged in the intermediate shock condition (0.4 mA). Freezing and corticosterone values at both testing times were positively related with shock intensity experienced at training. Therefore, our results show a complex regulation of CAMs of the immunoglobulin superfamily in the hippocampus that depends upon stressor intensity and time factors. In addition, the pattern of CAMs expression found in the 1 mA group (which is the one that shows higher post-training corticosterone levels and develops the stronger and longer-lasting levels of fear conditioning) supports the view that, after a first phase of synaptic de-adherence during consolidation, NCAM and L1 might participate in the stabilization of selected synapses underlying the establishment of long-term memory for contextual fear conditioning, and suggests that glucocorticoids might play a role in the observed regulation of CAMs. [source] Early nephron formation in the developing mouse kidneyJOURNAL OF ANATOMY, Issue 4 2001JONATHAN B. L. BARD This paper reports 3-dimensional confocal microscopy observations on how nephrogenic aggregates form from the NCAM- and Pax2-positive caps (4,5 cells deep) of condensed metanephric mesenchyme surrounding the duct tips of the mouse kidney. Aggregates of 6,8 cells are first seen at ,E12.5,12.75 immediately proximal to this cap, closely abutting the duct surface. As the tip advances, NCAM expression is maintained in the cap but is otherwise restricted to aggregates whose cells rapidly epithelialise, forming tubules that invade the duct epithelium. Pax2 expression studies shows how the rind of nephrogenic blastemal cells forms: as duct tips extend towards the kidney surface, the associated Pax2+ cells form patches of cells on the kidney surface. These observations revise our knowledge of the timing and process of nephron initiation. [source] Alcohol Exposure Alters the Expression Pattern of Neural Cell Adhesion Molecules During Brain DevelopmentJOURNAL OF NEUROCHEMISTRY, Issue 3 2000R. Miñana Abstract: Neural cell adhesion molecules (NCAMs) play critical roles during development of the nervous system. The aim of this study is to investigate the possible effect of ethanol exposure on the pattern of expression and sialylation of NCAM isoforms during postnatal rat brain development because alterations in NCAM content and distribution have been associated with defects in cell migration, synapse formation, and memory consolidation, and deficits in these processes have been observed after in utero alcohol exposure. The expression of NCAM isoforms in the developing cerebral cortex of pups from control and alcohol-fed mothers was assessed by western blotting, ribonuclease protection assay, and immunocytochemistry. The highly sialylated form of NCAM [polysialic acid (PSA)-NCAM] is mainly expressed during the neonatal period and then is down-regulated in parallel with the appearance of NCAM 180 and NCAM 140. Ethanol exposure increases PSA-NCAM levels during the neonatal period, delays the loss of PSA-NCAM, decreases the amount of NCAM 180 and NCAM 140 isoforms, and reduces sialyltransferase activity during postnatal brain development. Neuraminidase treatment of ethanol-exposed neonatal brains leads to more intense band degradation products, suggesting a higher content of NCAM polypeptides carrying PSA in these samples. However, NCAM mRNA levels are not changed by ethanol. Immunocytochemical analysis demonstrates that ethanol triggers an increase in PSA-NCAM immunolabeling in the cytoplasm of astroglial cells, accompanied by a decrease in immunogold particles over the plasma membrane. These findings indicate that ethanol exposure during brain development alters the pattern of NCAM expression and suggest that modification of NCAM could affect neuronal-glial interactions that might contribute to the brain defects observed after in utero alcohol exposure. [source] Developmental Changes of Cell Adhesion Molecule Expression in the Fetal Mouse LiverTHE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 10 2010Yoshinori Sugiyama Abstract Developmental changes of cell adhesion molecule expression, especially in nonparenchymal cells, have hardly ever been analyzed in the murine liver. The present study was undertaken to immunohistochemically examine the expression of NCAM, ICAM, VCAM, and N-cadherin during mouse liver development and in fetal liver cell cultures. NCAM was transiently expressed in mesenchymal cells of the septum transversum and sinusoidal cells in liver development. In vitro studies demonstrated that desmin-positive stellate cells expressed this cell adhesion molecule. NCAM expression in periportal biliary epithelial cells and connective tissue cells also coincided well with bile duct remodeling processes in the perinatal periods. Expression of ICAM and VCAM was transiently restricted to hepatoblasts, hepatocytes and hemopoietic cells in fetal stages. N-cadherin was expressed not only in hepatoblasts and hepatocytes, but also in nonparenchymal cells such as endothelial cells, stellate cells and connective tissue cells, however the expression was weak. These results suggest that each cell adhesion molecule may play an important role during development in hepatic histogenesis, including hepatoblast/hepatocyte-stellate cell interactions, hemopoiesis, and bile duct morphogenesis. Anat Rec 293:1698,1710, 2010. © 2010 Wiley-Liss, Inc. [source] Neural Cell Adhesion Molecule Expression in Adenoid Cystic Carcinoma of the Head and Neck,THE LARYNGOSCOPE, Issue 6 2000James A. Hutcheson MD Abstract Objective To investigate whether there is a correlation between neural cell adhesion molecule (NCAM) expression and perineural spread in patients with adenoid cystic carcinoma of the head and neck (ACCHN). Study Design Retrospective review of medical records and immunohistochemical staining of specimens from 37 patients treated at the University of Arkansas in Little Rock from 1987 to 1997. Methods Sections from paraffin-embedded specimens were e-amined for the presence of NCAM using monoclonal anti-NCAM antibody by avidin-biotin-pero-idase immunohistochemical staining. NCAM staining was scored in each specimen and correlated with the data obtained from patient charts. Results Twenty-five of 37 specimens (68%) showed histopathological evidence of perineural spread. All 37 specimens (100%) stained positive for NCAM, regardless of perineural spread status. Conclusion Our results suggested that the use of NCAM expression as a predictor of perineural spread is highly unlikely. [source] Dopamine D2 Receptor Binding, Drd2 Expression and the Number of Dopamine Neurons in the BXD Recombinant Inbred Series: Genetic Relationships to Alcohol and Other Drug Associated PhenotypesALCOHOLISM, Issue 1 2003Robert Hitzemann Background: It has not been established to what extent the natural variation in dopamine systems contribute to the variation in ethanol response. The current study addresses this issue by measuring D2 dopamine (DA) receptor binding, the expression of Drd2, the number of midbrain DA neurons in the BXD recombinant inbred (RI) series and then compares these strain means with those previously reported for a variety of ethanol and other drug-related phenotypes. Methods: Data were collected for 21 to 23 of the BXD RI strains and the parental strains. D2 DA receptor autoradiography was performed using 125I-epidepride as the ligand [Kanes S, Dains K, Cipp L, Gatley J, Hitzemann B, Rasmussen E, Sanderson S, Silverman S, Hitzemann R (1996) Mapping the genes for haloperidol-induced catalepsy. J Pharmacol Exp Ther 277:1016,1025]. Drd2 expression was measured using the Affymetrix oligoarray system. Immunocytochemical techniques were used to determine the number of midbrain DA neurons [Hitzemann B, Dains K, Hitzemann R (1994) Further studies on the relationship between dopamine cell density and haloperidol response. J Pharmacol Exp Ther 271:969,976]. Results and Conclusions: The range of difference in receptor binding for the RI strains was approximately 2-fold in all regions examined, the core, the shell of the nucleus accumbens (NAc) and the dorsomedial caudate-putamen (CPu); heritability in all regions was moderate,(h 2,0.35). Drd2 expression in forebrain samples from the RI and parental strains ranged 1.5- to 2-fold and h2 was moderate,0.47. Variation in the number of tyrosine hydroxylase (TH) positive neurons was moderate, 41% and 26% and h2 was low,0.19 and 0.15 for the ventral tegmental area (VTA) and substantia nigra compacta (SNc), respectively. Significant correlations were found between D2 DA receptor binding and the low dose (1.33 g/kg) ethanol stimulant response. (p < 0.002) and between Drd2 expression and conditioned place preference (CPP) (p < 0.0005). No significant correlations were detected between ethanol preference and either receptor binding or Drd2 expression; however, a significant correlation was found between preference and Ncam expression. Ncam is approximately 0.2 Mb from Drd2. Overall, the data suggest ethanol preference and CPP are associated with the expression of Drd2 or closely linked genetic loci. [source] Effects of Ethanol and Transforming Growth Factor , (TGF,) on Neuronal Proliferation and nCAM ExpressionALCOHOLISM, Issue 8 2002Michael W. Miller Background Developmental events targeted by ethanol are cell proliferation, neuronal migration, and neurite outgrowth; the latter processes being mediated by neural cell adhesion molecule (nCAM). TGF,1 affects all three of these events. Therefore, the effects of ethanol on transforming growth factor (TGF) ,1 mediated activities in neocortical neurons in vitro were examined. Methods Primary cultures of cortical neurons were obtained from 16-day-old fetuses and were treated with TGF,1 (0 or 10 ng/ml) and ethanol (0 or 400 mg/dl) for 48 hr. The effects of these substances on cell numbers, [3H]thymidine incorporation, and the expression of nCAM were determined. Results Both cell growth (the change in cell numbers over time) and cell proliferation were inhibited by TGF,1 and ethanol. The action of these two anti-mitogenic factors was additive. In contrast, TGF,1 also promoted the expression of three isoforms of nCAM. Likewise, ethanol also up-regulated nCAM expression. On the other hand, ethanol blocked TGF,1-mediated nCAM expression, particularly of the 120 and 180 kDa isoforms. Conclusions TGF, ligands inhibit neuronal proliferation and stimulate the expression of cell adhesion proteins that promote the movement of postmitotic neurons and process outgrowth. Ethanol alters these phenomena as well. Thus, in neurons, as in astrocytes, TGF,1 and ethanol may interact. [source] | |||||||||||||