ADORA1 and major depressive disorder: In our study, we also found an increase in A1 adenosine receptor expression after treatment with REMSD and fluoxetine alone or together and that the combined therapy further promoted A1 adenosine receptor expression, showing that the combined therapy of REMSD and fluoxetine could protect rats against depression and rat hippocampi against depression-induced damage and apoptosis via promoting expression of A1 adenosine receptor.