D4 receptor binding after 4 weeks of continuous infusion of antipsychotic drugs
| Brain Region | Controls | Olanzapine | Risperidone | Quetiapine | Clozapine 4-a | Fluphenazine 4-a |
|---|---|---|---|---|---|---|
| Cerebral cortex | ||||||
| Medial-prefrontal | 10.0 ± 0.6 (100) | 11.3 ± 0.8 (113) | 11.1 ± 0.7 (111) | 10.8 ± 0.3 (108) | (117) | (106) |
| Dorsolateral | 6.3 ± 0.3 (100) | 6.8 ± 0.4 (108) | 6.4 ± 0.5 (102) | 6.0 ± 0.6 (95) | (97) | (75) |
| Nucleus accumbens | 29.3 ± 1.1 (100) | 48.2 ± 2.8 (165)* | 38.9 ± 3.3 (133)* | 28.6 ± 3.3 (98) | (171)* | (224)* |
| Caudate-putamen | ||||||
| Medial | 31.4 ± 2.4 (100) | 50.2 ± 3.6 (160)* | 42.7 ± 1.8 (136)* | 29.1 ± 2.9 (93) | (143)* | (160)* |
| Lateral | 37.8 ± 1.6 (100) | 61.4 ± 1.3 (162)* | 51.6 ± 2.6 (137)* | 41.9 ± 4.6 (111) | (143)* | (163)* |
| Hippocampus | 18.0 ± 0.5 (100) | 29.0 ± 1.6 (161)* | 24.7 ± 0.9 (137)* | 19.1 ± 1.5 (106) | ||
| Entorhinal cortex | 6.9 ± 0.6 (100) | 7.4 ± 0.5 (107) | 7.3 ± 0.5 (106) | 8.2 ± 0.3 (119) |
Data are mean ± S.E.M. values for binding [fmol/mg of tissue and (percentage of control)], determined by quantitative autoradiography following continuous subcutaneous infusion of vehicle or antipsychotic drugs for 4 weeks, with significant differences from controls indicated in bold (* p < 0.05, N = 7 rats/group), all as described under Experimental Procedures.
↵4-a Data (percentage of control) for clozapine (40 mg/kg/day) and fluphenazine (1 mg/kg/day) were determined previously (Tarazi et al., 1997c) and are shown for comparison.