The effect of in vitro rotenone pretreatment on EFS-evoked [3H]DA release and on the levels of glutamate (Glu), aspartate (Asp), GABA and of the endocannabinoid 2-AG and anandamide (AEA) in wild-type (WT) and P2X
receptor knockout (KO) mice. A, B. Slices were perfused with Krebs solution and subjected to electrical field stimulation (25 V, 1 msec, 2 Hz, 240 shocks) during the 3rd and 13th sample collection period (S1, S2) after a 60-min preincubation with rotenone (10 μM, B) or Krebs' solution (A). [3H]DA release is expressed as fractional release (FR%, for calculation see Materials and methods) as a function of time (n = 5-8). C, D. Samples were analyzed using HPLC, and the results are expressed in nmol/mg protein (C) or in pmol/mg protein (D) (n = 5-8). Asterisks indicate significant differences from the corresponding control or between WT and KO mice as indicated (** P < 0.01).