Figure 2. Knockdown of PYK2 blocks LTD. A, B, PYK2 shRNA blocks LTD (A), but luciferase shRNA does not (B). Groups of four consecutive EPSC measurements were averaged, and then normalized to the average EPSC magnitude of the first 10 min of baseline recordings (pre-LTD induction). Statistical significance was assessed by comparing the average normalized EPSC of the last 10 min of recording. PYK2 shRNA: n = 12 pairs; p = 0.031, paired Student's t test. Luciferase shRNA: n = 12 pairs; p = 0.56, paired Student's t test. Insets show averaged EPSC traces from sample transfected and untransfected (untrans) cells (thick traces from position 1; thin traces from position 2). Calibration: 50 pA/25 ms. C, D, Neither PYK2 shRNA (C) nor luciferase shRNA (D) affected LTP. Groups of six consecutive EPSC measurements were averaged, and then normalized to the average EPSC magnitude of the first 3 min of baseline recording (pre-LTP induction); the average normalized EPSC of the last 10 min of recording was used to assess statistical significance. PYK2 shRNA: n = 9 pairs; p = 0.48, paired Student's t test. Calibration: 30 pA/25 ms. Luciferase shRNA: n = 7 pairs; p = 0.64, paired Student's t test. Calibration: 50 pA/25 ms. E, PYK2 shRNA and luciferase shRNA do not significantly alter baseline AMPAR transmission. Each data point represents the average EPSC amplitude of 60 consecutive synaptic responses; EPSC amplitude is shown in picoamperes. PYK2 shRNA paired recordings (transfected cell vs untransfected neighboring cell in the same slice): n = 12 pairs; p = 0.55 versus untransfected control, paired Student's t test. Luciferase shRNA paired recordings: n = 19 pairs; p = 0.50 versus untransfected control, paired Student's t test. Insets show averaged EPSC traces from a sample pair of transfected (trans) and neighboring untransfected (untrans) cells. Calibration: 20 pA/100 ms. F, PYK2 shRNA and luciferase shRNA have similar effects on NMDAR transmission. Each data point represents the average NMDAR EPSC amplitude of 60 consecutive synaptic responses; EPSC amplitude is shown in picoamperes. PYK2 shRNA paired recordings: n = 9 pairs, p = 0.024 versus untransfected control, paired Student's t test. Luciferase shRNA paired recordings: n = 18 pairs, p = 0.015 versus untransfected control, paired Student's t test. Calibration: 50 pA/100 ms.