Tulrampator (developmental code names S-47445, CX-1632) is a positive allosteric modulator (PAM) of the AMPA receptor (AMPAR), an ionotropic glutamate receptor, which is under development by RespireRx Pharmaceuticals (formerly Cortex Pharmaceuticals) and Servier for the treatment of major depressive disorder (as an adjunct), Alzheimer's disease, dementia, and mild cognitive impairment.

[1][2][3][4] Tulrampator was in phase II clinical trial for depression, but failed to show superiority over placebo.

[8] Tulrampator itself has been found in animals to enhance cognition and memory, to produce antidepressant-, antianhedonic-, and anxiolytic-like effects, and to have neurotrophic and neuroplasticity-promoting activities.

[3][4] Moreover, it has been found to increase levels of brain-derived neurotrophic factor (BDNF) in the hippocampus and to stimulate hippocampal neurogenesis.

[3][9] The rapidly-acting antidepressant effects of the NMDA receptor antagonist ketamine appear to be mediated through indirect/downstream activation of AMPARs.