“…NCAM and L1 can act by homophilic (Hoffman and Edelman, 1983;Lemmon et al, 1989), heterophilic (Pollerberg et al, 1987;Werz and Schachner, 1988;Grumet, 1992) and assisted homophilic binding, interacting with each other in the surface membrane of one cell (cis-interaction) via an oligomannosidic glycan (Horstkorte et al, 1993) and binding to L1 at an opposing cell surface (trans-interaction; Kadmon et al, 1990a,b). NCAM contains in its fourth Ig-like domain (Ig4) the binding site for the L1-associated oligomannosidic glycans (Horstkorte et al, 1993) and 10 amino acids derived from a variable alternatively spliced exon (VASE or , Santoni et al, 1989;Small et al, 1988) which is rarely expressed at early postnatal stages but becomes up-regulated at later stages in cerebellar and hippocampal neurons (Small and Akeson, 1990;Walsh et al, 1992). Fibroblasts transfected with NCAM with VASE and used as substrate show reduced neurite outgrowth-promoting activity for cerebellar neurons and PC12 cells Liu et al, 1993).…”