Figure 4.

Effect of 3,5-dibromo-L-phenylalanine (3,5-DBr-L-Phe) on endothelin-1 (ET-1)- and dizocilpine (MK-801)-induced disruption of prepulse inhibition (PPI) of the acoustic startle response. (A) The PPI test was performed 1 day prior and 3 days after the administration of ET-1. The animals were treated with 3,5-DBr-L-Phe (n= 15) or saline (n= 8) as described in Figure 1. (B and C) Startle response and PPI were measured in all rats before treatment (n= 34) and after administration of (i) Saline and MK-801 (0.15 mg·kg⁻¹) (n= 17) or (ii) 3,5-DBr-L-Phe (30 mg·kg⁻¹) and MK-801 (0.15 mg·kg⁻¹) (n= 17) (see text for details). *P < 0.05 relative to the control group. The average %PPI data for all three prepulse intensities for each treatment group is shown in Figure 4C.