P2RX7 and major depressive disorder: While effects mediated by P2X7 receptor occur mainly through neuroinflammatory response and inflammasome activation [44], it also interacts and interferes with other stress and depression-related mechanisms [19], including impaired serotonin, noradrenaline, glutamate, GABA and NO release and transmission, and reduced neurogenesis and neuroplasticity [19,45–51].