What knock-out animals tell us about the effects of caffeine.
Caffeine is well known for its complex pharmacological actions, in part reflecting the multiple molecular targets of caffeine. The adenosine receptors are the primary extracellular targets of caffeine. Since caffeine has similar affinity for several adenosine receptors, it has been difficult to determine which receptor subtypes mediate caffeine's effects using pharmacological tools. The development of genetic mutant mice deficient in adenosine receptors and other signaling molecules has allowed targeted inquiry into the molecular targets by which caffeine elicits its biological effects on behavior and gene expression. This review summarizes recent work using genetic knockout models to elucidate the mechanisms of caffeine action in the brain. This review focuses on insights into caffeine action from genetic knockout models on: (1) the molecular basis for caffeine's effects on psychomotor activity; (2) the involvement of adenosine receptors in caffeine-mediated arousal and cognitive effects; and (3) a novel approach using knockout animals coupled with microarray profiling to validate multiple molecular targets of caffeine in striatal gene expression.
Chen
Jiang-Fan
JF
Department of Neurology, Boston University School of Medicine, Boston, MA 02118, USA. chenjf@bu.edu
Yu
Liqun
L
Shen
Hai-Ying
HY
He
Jin-Cai
JC
Wang
Xiaotong
X
Zheng
Rongyuan
R
D000818:Animals; D001143:Arousal / Q000187:drug effects / Q000235:genetics; D002110:Caffeine / Q000494:pharmacology*; D003071:Cognition / Q000187:drug effects; D051937:Dopamine and cAMP-Regulated Phosphoprotein 32 / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects* / Q000235:genetics; D006801:Humans; D051379:Mice; D018345:Mice, Knockout; D009043:Motor Activity / Q000187:drug effects / Q000235:genetics; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology*; D011597:Psychomotor Performance / Q000187:drug effects*; D018047:Receptors, Purinergic P1 / Q000172:deficiency* / Q000235:genetics; D012890:Sleep / Q000187:drug effects / Q000235:genetics
D051937:Dopamine and cAMP-Regulated Phosphoprotein 32; D010726:Phosphodiesterase Inhibitors; D018047:Receptors, Purinergic P1; D002110:Caffeine