CNIH-2 deletion in single neurons by P0–2 injection (red circles) and in slice culture (black circles) caused a 54 ± 6% (n = 19) reduction in AMPAR-eEPSCs (Figure 1A), but no change in NMDAR-eEPSCs (Figure 1B). Because there was no significant difference between the results from acute and cultured slices, the data were combined. CNIH-2 deletion also caused a speeding in the decay of AMPAR-EPSCs in acute slices. This included eEPSCs (Figure 1C) and miniature EPSCs (mEPSCs) (Figure 1E). Furthermore, mEPSC amplitude was reduced (Figure 1D) consistent with a reduction in AMPAR number at individual synapses. The difference in magnitude between the evoked and mEPSCs can be explained by the fact that a threshold is required for detecting mEPSCs and many events fall below this threshold in the absence of CNIH-2. This is reflected in the large decrease in mEPSC frequency (Figure S2A). To quantitatively determine the effects of CNIH-2 on AMPAR kinetics we pulled somatic outside-out patches and used ultra-fast glutamate application to measure AMPAR deactivation (Figure 1F) and desensitization (Figure 1G). Both desensitization and deactivation time constants were
