Chronic caffeine exposure enhances adenosinergic inhibition of cerebral cortical neurons.
Chronic administration of caffeine (s.c. for a period of 14 days in escalating doses of 10-70 mg/kg) increased the sensitivity of rat cerebral cortical neurons to the inhibitory action of microiontophoretically applied adenosine. The sensitivity of spontaneously firing rat cerebral cortical neurons in caffeine-treated animals was compared with that of saline-treated controls using the same multiple-barrel micropipettes tested on the same day. Adenosine sensitivity was determined by the I.T50 method. The I.T50 value for 134 neurons in the caffeine-treated rats of 130.77 +/- 4.33 (S.E.M.) was significantly (P less than 0.001) different to that of 136 neurons in the saline-treated control rats (222.16 +/- 6.68), indicating a supersensitivity to adenosine in neurons which had been chronically exposed to caffeine.
Department of Physiology, Wayne State University School of Medicine, Detroit, MI 48201.
Y
Y
Lin
J W
JW
Phillis
D000241:Adenosine / Q000494:pharmacology*; D000818:Animals; D002110:Caffeine / Q000494:pharmacology*; D002540:Cerebral Cortex / Q000187:drug effects / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D004594:Electrophysiology; D008297:Male; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D012016:Reference Values
D002110:Caffeine; D000241:Adenosine