PF-03463275 is the novel azabicyclic glycine transporter 1 (GlyT1) inhibitor. Ketamine induced hallucinatory-like behaviors that were not reversed by PF-3463275. In contrast, all doses of PF-3463275 alleviated the deficit in spatial working memory induced by ketamine. PF-03463275 causes changes in electroretinogram (ERG) responses in albino rats. There was dose-dependent reduction in the amplitude of the rat ERG oscillatory potentials (OPs) following single subcutaneous administrations of the PF-03463275. Furthermore, the amplitude of OPs was negatively correlated to the concentration of PF-03463275 in the vitreous humor collected from rats immediately following ERG recordings. A slight increase in the amplitude and latency of the a-wave component of the ERG with PF-03463275 treatment was observed. Since the ERG changes occur in our rodent model with PF-03463275 at exposures comparable with those associated with visual disturbance in the clinic, it was proposed that the visual adverse effects reported in healthy volunteers treated with selective GlyT1 inhibitors may represent a retinal class effect. The dose-related GlyT1 occupancy of PF-03463275 is linear. While PF-03463275 did not show evidence of facilitating N-methyl-D-aspartate receptor function in the ketamine assay, it enhanced neuroplasticity in schizophrenia patients. PF-03463275 had been in phase II clinical trial for the treatment of schizophrenia. However, this development was discontinued.