CX546 is a selective positive AMPAR modulator; the prototypical ampakine agent. IC50 value: Target: AMPAR agonist in vitro: Treatments with the ampakine CX614 markedly and reversibly increased brain-derived neurotrophic factor (BDNF) mRNA and protein levels in cultured rat entorhinal/hippocampal slices [1]. in contrast to cyclothiazide or IDRA 21, the Ampakine CX546 binds specifically to the agonist bound nondesensitized receptor, most likely acting by destabilizing the desensitized receptor conformation [2]. In binding tests, CX546 caused an approximately 2-fold increase in the affinity for radiolabeled agonists, whereas CX516 was ineffective [3]. in vivo: Intraperitoneal injections of CX546 increased hippocampal BDNF mRNA levels in aged rats and middle-aged mice [1]. Administration of the positive modulator of alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid receptors (AMPAR), CX546, during the conditioning phase only, improved the disrupted LI in mGluR5 knockout mice and facilitated LI in control C57BL/6J mice, given extended number of conditioning trails (four conditioning stimulus-unconditioned stimulus) [4].