Neural cell adhesion molecule regulates cell contact-mediated changes in choline acetyltransferase activity of embryonic chick sympathetic neurons

Abstract

Abstract. El0 chick sympathetic ganglion cells display a cell contact-dependent rise in choline acetyltransferase (CHAT) specific activity over the first several days in culture. This effect can be mimicked by addition of crude membrane fractions prepared from El0 retina and adult chicken brain, but not by those from El0 brain. The effects of both cell-cell and membrane-cell contact are inhibited by the addition of anti-NeAM Fab fragments. The membranes capable of increasing ChAT and those which are ineffective all contain NCAM, however their relative levels of NCAM polysialic acid differ. Whereas membranes with high polysialic acid NCAM are ineffective, selective enzymatic removal of polysialic acid renders them capable of producing an increase in CHAT. The inhibition of NCAM-mediated adhesion produced by Fab fragments can be compensated for by addition of wheat germ agglutinin, but only with membranes whose NCAM has low levels of polysialic acid. Taken together, these data suggest that NCAM can regulate cell contact-mediated increases in ChAT activity. We propose that NCAMmediated adhesion promotes contact between cell membranes to allow the transmission of an otherwise NCAM-independent signal. In addition, NCAM's polysialic acid moiety appears to influence the ability of cells to transmit this signal, even in the presence of an alternative adhesion mechanism.

Development of the cholinergic neurotransmitter phenotype in postganglionic sympathetic neurons

“…Comparing acetylcholine and ChAT levels with the number of synapses formed in the ganglion that may contribute preganglionic ChAT activity to the measurements, it was concluded that, because of the minor number of synaptic profiles at embryonic day 10, acetylcholine and ChAT were derived from cholinergic neuroblasts (Hruschak et al 1982). This conclusion was supported by ChAT activity determinations in cultured neurons from lumbosacral sympathetic ganglia of E7 (Ernsberger et al 1997), E10 (Acheson and Rutishauser 1988) and E12 (Edgar et al 1981) chick embryos. The observation of ChAT activity in E7 chick sympathetic neurons is of particular relevance since this is before target contact.…”

Multistratified Expression of Polysialic Acid and Its Relationship to VAChT-containing Neurons in the Inner Plexiform Layer of Adult Rat Retina

“…We have easily identified all five strata by using dual immunostaining techniques and confocal laser scanning microscopy. Acheson and Rutishauser (1988) have demonstrated that NCAM during development regulates cell contact-mediated changes in choline acetyltransferase (ChAT) activity of embryonic chick sympathetic neurons in vitro, and that the presence of a PSA moiety on NCAM blocks the cell contact-mediated increase in ChAT activity. The high level of PSA expression in the IPL at the peripheries of cholinergic neuron dendrites suggests influence on ChAT activity during development.…”

A Human STX cDNA Confers Polysialic Acid Expression in Mammalian Cells

“…Furthermore, PSA has been reported to be associated with only two proteins, the neural cell adhesion molecule (N-CAM) and sodium channel ␣ subunits (9,10). Changes in the amount of PSA on N-CAM modulates the adhesive properties of N-CAM, and also affects the cell surface properties of other molecules like some integrins, N-cadherin, and G4/NgCAM (11)(12)(13)(14). These effects are presumed to be due to the unusual physicochemical properties of this very large, abundant, negatively charged, and linear cell surface polyglycan (14).…”