Table 1.
PET studies examining the susceptibility of extrastriatal dopamine D2 receptor radioligands for manipulation by dopaminea
| Receptor | Radioligand | Challenge | Species | Protocol | Outcome parameter | Effect on outcome parameter | Reference |
|---|---|---|---|---|---|---|---|
| D2R | [11C]FLB 457 | Amphetamine (2 mg/kg i.v., 15 min and 3 h prior) vs. baseline | Monkey (n = 3) | B | SBR | ↓6–16 % and ↓2–16 % in neoCx and thalamusb | (Chou et al. 2000) |
| [11C]FLB 457 | Methamphetamine (1 mg/kg i.v., 15 min prior ) vs. baseline | Monkey (n = 3) | B | BP ND | ↓3–7 % in frontal Cx, thalamus, and temporal Cxb | (Okauchi et al. 2001) | |
| [11C]FLB 457 | Nicotine (32 μg/kg + 0.8 μg/kg/min and 100 μg/kg + 2.53 μg/kg/min i.v., 30 min prior) and saline | Monkey (n = 5 and 5 and 5) | B | V T | NS | (Tsukada et al. 2005a) | |
| [11C]FLB 457 | MK801 (0.03, 0.1, and 0.3 mg/kg i.v., 30 min prior) vs. saline | Monkey (n = 8) | B | V T | NS, ↓∼15 % and ↓35 % in prefrontal Cx | (Tsukada et al. 2005b) | |
| [11C]FLB 457 | Ketamine (200 ng/ml target in plasma i.v., 15 min prior to 89 min post) and control | Human (n = 8 and 8) | B | BP ND | ↓11 % in posterior cingulate Cx | (Aalto et al. 2005) | |
| [11C]FLB 457 | Methylphenidate (40 and 60 mg p.o., 1 h prior) vs. placebo | Human (n = 5 and 5) | B | V T | ↓6–7 % in frontal Cx, temporal Cx, and thalamus | (Montgomery et al. 2007) | |
| BP ND | NS | ||||||
| [11C]FLB 457 | d-Amphetamine (0.3 mg/kg i.v., 5 min prior) and placebo | Human (n = 12 and 11) | B | V T | NS | (Aalto et al. 2009) | |
| BP ND | ↓13 % in hippocampus and posterior cingulate | ||||||
| [11C]FLB 457 | Amphetamine (0.5 mg/kg p.o., 3 h prior) vs. baseline | Human (n = 12) | B | BP P | ↓12 % in parietal Cx | (Narendran et al. 2009) | |
| BP ND | ↓7–13 % in various regions | ||||||
| [11C]Fallypride | BP P | NS | |||||
| BP ND | ↓8 % in temporal Cx | ||||||
| [11C]FLB 457 | α-Methyl-para-tyrosine (103–129 mg/kg p.o., over 2 days prior) vs. baseline | Human (n = 6) | B | BP P | NS | (Frankle et al. 2010) | |
| BP ND | ↓9 % in temporal Cx | ||||||
| [11C]FLB 457 | d-Amphetamine (0.3, 0.5, and 1.0 mg/kg i.v., 30 min prior) vs. baseline | Monkey (n = 7, 9, and 4) | B | BP ND | ↓6 %, ↓16 %, and ↓24 % in frontal Cx | (Narendran et al. 2014) | |
| [11C]FLB 457 | Amphetamine (0.4–0.5 mg/kg p.o., 3 h prior) vs. baseline | Human (n = 6) | B | BP ND (2TC) | NS | (Sandiego et al. 2015) | |
| BP ND (SRTM) | ↓8–13 % in various regions | ||||||
| [18F]Fallypride | d-Amphetamine (1.0 mg/kg i.v., 5 min prior) vs. baseline | Monkey (n = 3) | B | BP ND | ↓25–36 % in various regions | (Slifstein et al. 2004) | |
| d-Amphetamine (0.3 and 0.5 mg/kg i.v., 260 min post) vs. baseline | Monkey (n = 2) | BI | ↓−1–14 % and ↓10–34 % in various regions | ||||
| [18F]Fallypride | Amphetamine (0.60 mg/kg i.v., 15–30 min prior) vs. baseline | Monkey (n = 2) | B | BP ND | ↓16–39 % in various regionsb | (Mukherjee et al. 2005) | |
| Amphetamine (1.13 mg/kg i.v., 15 min prior) vs. baseline | Monkey (n = 1) | BP ND | ↓14–39 % in various regionsb | ||||
| Amphetamine (0.70 mg/kg i.v., 45 min post) vs. baseline | Monkey (n = 1) | SBR | ↓12–38 % in various regionsb | ||||
| [18F]Fallypride | d-Amphetamine (0.43 mg/kg p.o., 3 h prior) vs. baseline | Human (n = 14) | B | BP ND | ↓3–7 % in various regions | (Riccardi et al. 2006) | |
| [18F]Fallypride | d-Amphetamine (0.5 mg/kg p.o., 3 h prior) vs. baseline | Human (n = 14) | B | BP ND | ↓8–13 % in various regions | (Cropley et al. 2008) | |
| α-Methyl-para-tyrosine (3 g/70 kg/day over 44 h) vs. baseline | Human (n = 8) | NS | |||||
| [18F]Fallypride | α-Methyl-para-tyrosine (71.4 mg/kg p.o., over 26 h prior) vs. baseline | Human (n = 6) | B | BP ND | ↑13 % in substantia nigra | (Riccardi et al. 2008) | |
| [18F]Fallypride | d-Amphetamine (0.3 mg/kg i.v., 30 min prior) vs. baseline | Human (n = 15) | B | BP P | ↓11–70 % in various regions | (Slifstein et al. 2010) | |
| BP ND (SRTM) | ↓4–13 % in various regions | ||||||
| [18F]Fallypride | S-Ketamine (0.1 mg/kg bolus + 0.01 mg/kg/min i.v., 35 min prior to 30 min post) vs. placebo | Human (n = 10) | B | BP ND | NS | (Vernaleken et al. 2013) |
B bolus, BP ND binding potential non-displaceable, BP P binding potential plasma, Cx cortex, NS no statistically significant effect, SBR specific binding ratio, V T distribution volume
aThis table solely includes PET studies examining dopamine changes in extra-striatal regions. The authors refer the reader to a previous review article (Laruelle 2000) for a summary on studies examining striatal dopamine release
bNo statistical analysis reported