Over-expression of FRRS1L does not change AMPA receptor-mediated synaptic transmission. (A) Representative image of dendrites shows that over-expression of FRRS1L did not change GluA1 surface and total levels nor the ratio of GluA1 surface to total expression in cultured hippocampal neurons (Control: n = 12; FRRS1L: n = 26, sGluA1: p = 0.36; tGluA1: p = 0.57; sGluA1/tGluA1: p = 0.21, t-test). (B,C) Over-expression of FRRS1L did not change AMPA (B, n = 12, p = 0.96, paired t-test) and NMDA (C, n = 12, p = 0.10, paired t-test) EPSCs of hippocampal pyramidal neurons in organotypic hippocampal slice cultures. The open circles represent all pair recordings, the solid circle shows the average of all pair recordings. Scale bar, 20 pA and 100 ms for AMPA EPSC; 20 pA and 40 ms for NMDA EPSC. (D) The weighted decay time constant of AMPA EPSCs was not changed in neurons over-expressing FRRS1L (n = 12 for both conditions, p = 0.46, t-test). (E) The paired pulse ratio (PPR) was not changed in neurons over-expressing FRRS1L (n = 12, p = 0.81, t-test). Scale bar, 20 pA and 100 ms.