A. Representative traces of mEPSCNMDAR were recorded before (Ctrl), during bath perfusion of 200pM (gp120), and during bath perfusion of gp120 and T140 (gp120+T140). Data showed that the frequency of mEPSCNMDAR was increased by bath application of gp120, which was partially blocked by addition of T140 to the bath. B-C. Bar graph illustrates that gp120 increased the mean frequency of mEPSCNMDAR, but not the mean amplitude, suggesting a presynaptic site for gp120 action. The gp120-associated increase of mean frequency was attenuated by T140, a specific CXCR4 antagonist, indicating gp120 may interacts with chemokine receptor CXCR4. Graphed values are the means ± SEM, n=9, *p<0.05 as determined by one-way ANOVA test.