Possible Interaction: Caffeine and Serotonin

“In addition, caffeine increases serotonin concentration in brainstem regions that have excitatory projections to spinal motor neurons.”

“The experiments also show caffeine reversibly inhibits 5-HT elicited-InsP3 mediated Ca2+ responses with an IC50 of 6.87x10(-4) M and 10 mM caffeine fully inhibits CCE.”

“In normal and isolated-aggressive mice, caffeine induces modifications of both the level and the turnover of brain serotonin.”

“Similarly, administration of caffeine , which enhances the contribution of calcium-induced calcium release to the afterhyperpolarization, enhanced the effect of serotonin.”

“In addition, 4 weeks after … treatment, co-administration of caffeine with MDA (but not … a reduction in 5-HT and 5-hydroxyindole acetic acid (5-HIAA) concentrations in frontal cortex (to 61% and 58% … control, respectively), hippocampus (48% and 60%), striatum (79% and 64%) and amygdala (63% and 37%).”

“ Caffeine abolished the contractile effects of 5-HT , ACH, and KCl.”

“Therefore, it can be concluded that the serotonin system interacts with the analgesic action of caffeine and that a long-term use of clomipramine probably triggers subsensitivity of adenosine receptors.”

“Pretreatment with 33 mg/kg coffee or 1.7 mg/kg caffeine reduced the second restraint-induced increase in the neurotransmitters, especially 5-HT , but neither saline nor 1.7 mg/kg chlorogenic acid did.”

“ Caffeine injected at doses of 20, 40 and 80 mg/kg increased brain levels of tryptophan, 5-hydroxytryptamine (5-HT) and 5-hydroxyindole acetic acid (5-HIAA) in rat brain.”

“The results reveal that opiate receptors (but not adrenoceptors, 5-HT , dopamine or benzodiazepine receptors) may play a role in modulating the hypothermic action of caffeine and possibly other methylxanthines.”