Specific-to-Nonspecific 123I-FP-CIT Binding Ratios, Obtained 1 and 3 Hours After Injection of Radiotracer, in a DAT-Rich Brain Area (Striatum) and in SERT-Rich Areas (Midbrain and Diencephalon)
| 1 h after injection* | 3 h after injection | |||
|---|---|---|---|---|
| 123I-FP-CIT Binding | Placebo | Paroxetine† | Placebo | Paroxetine |
| DAT | ||||
| Striatum/cer.‡ | 2.23 ± 0.67 | 2.37 ± 0.55 | 3.99 ± 0.44 | 4.12 ± 0.90 |
| Striatum/occ. | 2.99 ± 0.75 | 3.15 ± 0.48 | 4.20 ± 0.37 | 4.57 ± 0.53§ |
| SERT | ||||
| Midbrain/cer. | 0.10 ± 0.11 | 0.01 ± 0.15 | 0.20 ± 0.20 | −0.02 ± 0.08§ |
| Midbrain/occ. | 0.36 ± 0.08 | 0.25 ± 0.15§ | 0.24 ± 0.16 | 0.07 ± 0.09§ |
| Diencephalon/cer. | 0.23 ± 0.17 | 0.16 ± 0.17 | 0.43 ± 0.20 | 0.26 ± 0.19¶ |
| Diencephalon/occ. | 0.53 ± 0.13 | 0.44 ± 0.18¶ | 0.48 ± 0.10 | 0.37 ± 0.12¶ |
↵* In 1 control subject, cerebellum and midbrain area were not adequately scanned 1 h after injection of radiotracer; therefore, ratios of specific over cerebellar (cer.) binding are provided for 7 control subjects instead of 8.
↵† Placebo or paroxetine tablets (20 mg per session) were taken orally approximately 3 and 27 h before injection of radiotracer.
↵‡ Ratios are expressed as specific to nonspecific binding (±SD). Nonspecific binding represents activity in cerebellum (cer.) or occipital cortex (occ.).
↵§ Statistically significantly different from placebo condition.
↵¶ A trend for statistically significant difference (P = 0.054−0.14).
Healthy control subjects (n = 8) received placebo or paroxetine before injection of radiotracer (double-blind, crossover study design).