Gangliosides GM1 and GD1b are not polarized in mature hippocampal neurons

Analysis of the binding of cholera toxin to ganglioside GM1 in both living and fixed neurons, and comparison with the distribution of defined axonal a nd dendritic proteins, demonstrates that ganglioside GM1 is distributed in a non-polarized manner over the axonal and dendritic plasma membranes of ma ture, cultured hippocampal neurons, Likewise, ganglioside GD1b is also dist ributed in a non-polarized manner. These results suggest that a recent repo rt [Ledesma, M.D. et al. EMBO J, 18 (1999) 1761-1771] proposing that gangli oside GM1 is highly enriched on the axonal versus dendritic membrane of hip pocampal neurons may need to be re-evaluated. (C) 1999 Federation of Europe an Biochemical Societies.