Role of acetylated gangliosides on neurite extension

We have investigated the role of 9-O-acetylated gangliosides identified by the Jones monoclonal antibody (Jones mAb) in the elongation of neurites extended by neurons of embryonic rat dorsal root ganglia (DRG) explants grown on laminin substratum. The behavior of individual growth cones was recorded using a time-lapse video-enhanced imaging system before and after the addition of antibodies that recognize specific gangliosides known to be expressed on these growth cones. It was possible to demonstrate that the advance of growth cones on laminin was halted in the presence of Jones mAb. The onset of effects was rapid and signaled by an immediate cessation of elongation, a loss of lamellipodia and a retrieval of axoplasm. This effect was partially reverted by washing the explants for several minutes with culture medium. mAb A2B5 which also recognizes gangliosides expressed on these growth cones does not induce any change on the growth rate. Our findings show that 9-O-acetylated gangliosides may play an important role on the extension of growth cones and consequently influence navigation and pathway finding during development.