Figure 5.
Acute extracellular DA concentrations were assessed in striata of rats treated with MDMA (10 mg/kg per injection for 4 times, i.p., every 2 h for 6 h)(A) or saline (1 ml/kg for 4 times, i.p., every 2 h for 6 h)(B), and 5-HT (C) and DA (D) tissue content was measured 1 week later. All probes were reverse dialyzed with aCSF, NSD 1015 (100 μm), l-tyrosine (500 μm; TYR), or the combination of l-tyrosine and NSD 1015 (TYR + NSD). A, NSD 1015 attenuated the increase in extracellular DA concentrations after MDMA and the l-tyrosine-induced enhancement of extracellular DA after MDMA. Arrows denote injections of MDMA. The inset denotes infusion conditions. Data are expressed in picograms of DA per 20 μl of dialysate ± SEM. TYR infusion group is significantly greater than the NSD1015 and TYR + NSD 1015 groups at all time points and different from aCSF during hours 1–5 (p < 0.05); NSD 1015 infusion is significantly less than TYR and a CSF groups at all time points and less than TYR+NSD1015 during hours 1–5 (p < 0.05). B, Local perfusion of NSD 1015 decreased basal DA. Data are expressed as average of the basal DA concentration across two baseline samples in picograms per 20 μl of dialysate ± SEM. *p < 0.05 compared with aCSF infusion and l-tyrosine; ^p < 0.05 compared with l-tyrosine infusion. C, Reverse dialysis of NSD 1015 blocked MDMA-induced 5-HT depletions in striatum as well as the l-tyrosine-induced enhancement of these depletions. Inset denotes systemic injection conditions. D, None of the infusion conditions affected DA tissue content after MDMA. The inset denotes systemic injection conditions. Data in C and D are expressed in 5-HT or DA picograms per microgram of protein ± SEM, respectively. *p < 0.05 compared with saline-treated control animals; ^p < 0.05 compared with all other infusion groups in MDMA-treated animals. n = 6–8 rats per group.