A key role of the basal ganglia in pain and analgesia - insights gained through human functional imaging

Molecular Pain

Table 3 Positron Emission Tomography (PET) studies of Pain.

Study Type	Condition	Receptor Binding	C	Pu	NAc	Reference
Acute Pain
	Thermal Pain	Contact Heat (15)O-water		+		[161]
		Contact Heat (15)O-water		+		[162]
		Contact Heat (15)O-water		+		[163]
	Contact Heat (Pain Threshold)	Dopamine receptor binding (11C) Raclopride		Binding - inverse correlation to Heat thershold		[133]
	Muscle Pain Hypertonic Saline	(15)O-water		+		[164]
		Dopamine Receptor Binding (11C) Raclopride	+	+	+	[135]
	Visceral Pain	Gastric Distenton (15)O-water	+			[165]
Placebo
	Muscle Pain Hypertonic Saline	Opioid and Dopamine receptor binding Placebo (11C) Raclopride (11C) Carfentanil			Increased opioid and dopamine release	[65]
		Opioid and Dopamine receptor binding Placebo (11C) Raclopride (11C) Carfentanil			Decrease opioid and dopamine release	[65]
Chronic Pain
	Neuropathic Pain (Burning Mouth)	6-[(18)F]fluorodopa		Decreased presynaptic dopamine function		[72]
	Neuropathic Pain	Motor Cortex Stimulation (15)O-water		+		[141]
	Atypical Facial Pain	Dopamine receptor binding [11C]raclopride		Increased D2 binding		[73]
	Fibromyalgia	μ receptor (11C) Carfentanil			Decreased Opioid Binding	[166]
		Dopamine receptor (11C) Raclopride			Decrease dopamine release	[74]
Analgesics
	Fentanyl	Opioid Effects (15)O-water	+			[167]
	Ketamine	NMDA Receptor Binding (n-methyl11C)-ketamine	+	+		[168]

ISSN: 1744-8069