Table 1.

5-HT_2AR agonist DOI affinity calculated from [³H]Ketanserin competition curves in mouse striatum and HEK293 cells expressing 5-HT_2AR and D₂R or 5-HT_2AR alone.

Receptor system	Ligand	Ki (M)		% High
		Ki-high	Ki-low
HEK-5HT2AR-D2R	Vehicle	NA	7.7 × 10−9 ± 0.25	NA
	Quinpirole (10−5 M)	6.2 × 10−11 ± 0.22	1.7 × 10−8 ± 0.32	46 ± 3
HEK-5HT2AR	Vehicle	3.2 × 10−9 ± 0.18	6.1 × 10−7 ± 0.4	41 ± 5
	Quinpirole (10−5 M)	1.5 × 10−9 ± 0.45	1.3 × 10−7 ± 0.33	48
Mouse striatum	Vehicle	NA	2.5 × 10−7 ± 0.26	NA
	Quinpirole (10−5 M)	6.5 × 10−11 ± 0.81	5.1 × 10−7 ± 0.89	44 ± 2
	Raclopride (10−6 M)	NA	6.6 × 10−7 ± 0.24	NA
	Quinpirole (10−5 M) + raclopride (10−6 M)	NA	6.9 × 10−7 ± 0.1	NA

DOI competition of [³H]Ketanserin binding was performed in the absence (vehicle) or in the presence of D₂R agonist quinpirole (10⁻⁵ M) and/or D₂R antagonist raclopride (10⁻⁶ M). Competition curves were analyzed by nonlinear regression to derive dissociation constants for the high- (K_i-high) and low- (K_i-low) affinity states of the receptor. % High refers to the percentage of high-affinity binding sites as calculated from nonlinear fitting. One-site model or two-site model as a better description of the data was determined by F test. Two-site model, p < 0.05. NA, two-site model is not applicable (p > 0.05). K_i; averages are expressed as means ± SEM of at least three separate experiments.

DOI displacement curve of [³H]Ketanserin with quinpirole (10⁻⁵ M) compared to the one with vehicle: F[2,43] = 3.42, *p < 0.05 in HEK-5-HT_2AR-D₂R; F[2,43] = 7, *p < 0.01 in HEK-5-HT_2AR and F[2,43] = 12.88, **p < 0.001 in mouse striatum.

DOI displacement curve of [³H]Ketanserin with quinpirole (10⁻⁵ M) + raclopride (10⁻⁶ M) compared to the one with vehicle: F[2,40] = 3.2, *p < 0.05 in mouse striatum.