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. 2004 Jan 7;24(1):53–62. doi: 10.1523/JNEUROSCI.4503-03.2004

Figure 4.

Figure 4.

Endocannabinoids modulate excitatory synaptic transmission in rat anterior VTA. A, Superfusion of AM281 (500 nm) by itself produces a significant increase of NMDA EPSCs (n = 6; p < 0.005). All data are normalized to the respective baseline (5 min of baseline). Black bars show the time of superfusion of the drug. The inset shows 10-trace averages of NMDA EPSCs before (black line) and during application of AM281 (gray line). Calibration: 100 pA, 20 msec. B, Bath application of SR (1 μm) per se significantly increased NMDA EPSCs (n = 8; p < 0.0001). All data are normalized to the respective baseline (5 min of baseline). Black bars show the time of superfusion of the drug. SEM bars are smaller than symbols in some cases. The inset shows representative traces of NMDA EPSCs before (black line) and during application of SR (gray line). Calibration: 100 pA, 20 msec. C, Bath application of the selective VR1 antagonist capsazepine (CPZ; 10 μm, open circles) produced a significant decrease of NMDA EPSCs on its own (n = 5; p = 0.0002). Coapplication (closed circles) of the endocannabinoid reuptake inhibitor AM404 (10 μm) with CPZ further decreased NMDA EPSCs (n = 5; p = 0.0005). All data are normalized to the respective baseline (5 min of baseline). Black bars show the time of superfusion of the drugs. The inset shows 10-trace averages of NMDA EPSCs before (black line) and during application of CPZ (dashed line) and CPZ with AM404 (gray line). Calibration: 100 pA, 20 msec. D, Superfusion of methanandamide (mAEA; 2 μm) did not significantly affect NMDA EPSCs (n = 5; p > 0.05). All data are normalized to the respective baseline (5 min of baseline). Black bars show the time of superfusion of the drug. The inset shows 10-trace averages of NMDA EPSCs before (black line) and during application of mAEA (gray line). Calibration: 100 pA, 20 msec. E, Coapplication of mAEA (2 μm) with CPZ (10 μm) significantly decreased NMDA EPSCs (n = 5; p < 0.0002). All data are normalized to the respective baseline (5 min of baseline). Black bars show the time of superfusion of the drugs. SEM bars are smaller than symbols in some cases. The inset shows representative traces of NMDA EPSCs before (black line) and during application of mAEA with CPZ (gray line). Calibration: 100 pA, 20 msec. F, The VR1 agonist capsaicin (CPS; 1 μm, open circles) induces a robust increase of NMDA EPSCs (n = 5; p < 0.0001), that was prevented by coapplication of CPZ (10 μm; n = 5; p < 0.0001; closed circles). All data are normalized to the respective baseline (5 min of baseline). Black bars show the time of superfusion of the drugs. SEM bars are smaller than symbols in some cases. The inset shows representative traces of NMDA EPSCs before (black line) and during application of CPS (dashed line) and CPS with CPZ (gray line). Calibration: 100 pA, 20 msec.