Electrical membrane properties of cultured dorsal root ganglion neurons from trisomy 19 mouse fetuses: a comparison with the trisomy 16 mouse fetus, a model for Down syndrome.

Because of synteny between mouse chromosome 16 and human chromosome 21, murine trisomy 16 (Ts16) has been considered an animal model for Down syndrome. Indeed, previous investigations have demonstrated that action potentials of cultured dorsal root ganglion (DRG) neurons from human trisomy 21 (Down syndrome) or mouse Ts16 fetuses show increased depolarization and repolarization rates, and decreased spike duration, compared to control neurons. In order to determine the specificity of these changes, we studied the electrical membrane properties of DRG neurons in culture from trisomy 19 (Ts19) and control fetal mice, using the whole cell patch-pipette recording technique. We found no significant differences in action potential parameters and passive membrane properties between Ts19 and control neurons. These findings support the notion that the alterations previously reported in Ts16 DRG neurons are specific, and not a general consequence of genetic imbalance imposed by autosomal trisomies.