Dopaminergic effects of caffeine in the human striatum and thalamus

: Kaasinen V, Aalto S, Nagren K, Rinne JO

Publisher: LIPPINCOTT WILLIAMS & WILKINS

: 2004

: NeuroReport

: NEUROREPORT

: 15

: 2

: 281

: 285

: 5

: 0959-4965

DOI: https://doi.org/10.1097/01.wnr.0000109985.85243.b0

Epidemiological studies have provided evidence that caffeine, an adenosine receptor antagonist, reduces the risk for Parkinson's disease. There are indications of specific interactions between striatal adenosine A(2A) and dopamine D-2 receptors, but the in vivo effects of caffeine on human dopamine system have not been investigated. In the present study, the dopaminergic effects of caffeine were examined with [C-II]raclopride positron emission tomography (PET) in eight healthy habitual coffee drinkers after 24 h caffeine abstinence. Compared to oral placebo, 200 mg oral caffeine induced a 12% decrease in midline thalamic binding potential (p < 0.001). A trend-level increase in ventral striatal [C-II]raclopride binding potential was seen with a correlation between caffeine-related arousal and putaminal dopamine D-2 receptor binding (r = -0.81, p = 0.03). The findings indicate that caffeine has effects on dopaminergic neurotransmission in the human brain, which may be differential in the striatum and the thalamus.