Caffeine Combats Stress

Many coffee and tea drinkers claim that drinking these beverages appears to have a calming effect, perhaps as a result of the associated mental break or socialization with others.  Manuella P. Kaster, from the University of Coimbra (Portugal), and colleagues  have revealed a molecular mechanism by which  caffeine may exert a stress-reducing effect.    The researchers administered a caffeinated beverage to lab mice, and then exposed the animals to a stressful environment.  The team observed that brain levels of adenosine A2A receptors (A2AR) rose.  Further, the investigators found that blocking A2AR activity via drugs or by removing the gene for A2AR caused the same effect as giving the mice caffeine.  Observing a reduction in both synaptic plasticity and protein density,  the study authors submit that: “These results herald a key role for synaptic [adenosine A2A receptors] in the control of chronic stress-induced modifications and suggest [adenosine A2A receptors]  as candidate targets to alleviate the consequences of chronic stress on brain function.”