Responses to NMDA in cultured hippocampal neurons from trisomy 16 embryonic mice.

The trisomy 16 (Ts16) mouse is regarded as a model of human trisomy 21 (Ts21), or Down syndrome. The ionic current evoked by the glutamate receptor agonist N-methyl-D-aspartate (NMDA) was investigated in cultured hippocampal neurons from embryonic Ts16 and control diploid mice. In both Ts16 and control neurons, NMDA- (6-150 microM) evoked a similar inward current. The reversal potential, the minimum current, the dose response plot of the conductance, the effect of Mg2+ on the current-voltage plot and the inhibition by D-2-amino-5-phosphonovaleric acid (AP5; 50 microM) showed no significant difference between Ts16 and control neurons. These data suggest that, although voltage-dependent ion channels are reported to have altered active properties in Ts16 neurons, NMDA-evoked currents are not altered.