Table 5.
D4 receptor binding in juvenile rats (PD 42) after three weeks of daily administration of risperidone
| Brain region | Controls | RSP(0.3 mg/kg) | Juvenile Rats RSP(1.0 mg/kg) | RSP(3.0 mg/kg) | Adult Rats RSP(3.0 mg/kg) |
|---|---|---|---|---|---|
| Cerebral cortex | |||||
| Medial-prefrontal | 19.8± 0.8 (100) | 20.4 ± 1.4 (103) | 20.2 ± 1.4 (102) | 21.0 ± 1.1 (106) | (111) |
| Dorsolateral | 16.4 ± 2.0 (100) | 15.1 ± 0.9 (92) | 16.4 ± 1.3 (100) | 18.1 ± 1.5 (110) | (102) |
| Nucleus accumbens | 30.6 ± 3.8 (100) | 39.3 ± 2.9 (128)* | 40.0 ± 2.5 (131)* | 40.5 ± 2.6 (132)* | (133)* |
| Caudate-putamen | |||||
| Medial | 31.1 ± 3.2 (100) | 40.5 ± 2.8 (130)* | 41.1 ± 2.8 (132)* | 42.3 ± 1.9 (136)* | (136)* |
| Lateral | 42.8 ± 3.1 (100) | 56.4 ± 2.7 (132)* | 59.2 ± 2.6 (138)* | 60.4 ± 2.2 (141)* | (137)* |
| Hippocampus | 19.2 ± 1.3 (100) | 24.6 ± 1.3 (128)* | 26.3 ± 1.9 (137)* | 29.2 ± 2.4 (152)* | (137)* |
Data are mean ± SEM values for binding (fmol/mg tissue, [% of control]), determined by quantitative autoradiography following daily i.p. injection of vehicle or risperidone (RSP) for 3 weeks, with significant differences from controls indicated in bold ([*] p<0.05, N=6 rats/group). Data (% of control) for RSP (3 mg/kg/d) in adult animals were reported previously (Tarazi et al., 2001) and are shown for comparison.