Figure 6.

Effects of striatal 5-HT_1AR stimulation on extracellular nigral GABA in a D1R-mediated model of dyskinesia. Rats in Experiment 2 received unilateral 6-OHDA of the MFB and 3 weeks later were primed with the D1R agonist SKF81297 (SKF; 0.8 mg/kg, sc) every 2–3 days for a total of 3 days. Dyskinetic rats (N = 26) underwent a microdialysis procedure including 40 min baseline, 120 min vehicle treatment, 120 min drug treatment, and 60 min postdrug treatment sampling (dialysate collected every 20 min). Intrastriatal drug infusion included: Vehicle (VEH; aCSF), the full 5-HT_1AR agonist ±8-OH-DPAT (DPAT; 7.5 mM), or combined DPAT (7.5 mM) + the 5-HT_1AR antagonist WAY100635 (WAY; 4.6 mM), followed 10 min later by systemic treatment injections of Vehicle (VEH; 20% DMSO, 0.9% NaCl) or SKF. ALO AIMs and rotations were observed during this time. Treatment groups consist of n = 5–9/treatment group. (A) Lines depict the means (expressed as % baseline ± SEM) of nigral GABA. (B) Bars depict the means (expressed as % baseline ± SEM) of nigral GABA during the 120 min of vehicle (VEH (aCSF) + VEH) and 120 min of drug treatments. Effects over time were determined by two-way mixed design ANOVAs, main effects for treatment collapsed across time were analyzed with one-way ANOVAs, and LSD post hoc tests were utilized. *p < 0.05 vs VEH + SKF; +p < 0.05 vs DPAT (7.5 mM) + WAY (4.6 mM) + SKF. #p < 0.05 vs VEH + VEH; ×p < 0.05 vs DPAT (7.5 mM) + VEH.