PDE5A and memory impairment: In addition, agents that inhibited PDE5 improved performance in the NOR, MWM, STFP, and spontaneous alternation tests (Akar et al., 2014; Devan et al., 2014), which included restoration of scopolamine-induced memory impairments (Zhang et al., 2018; Tabrizian et al., 2021) and enhanced learning in Alzheimer’s disease models (Cuadrado-Tejedor et al., 2011; García-Barroso et al., 2013; Kang et al., 2022).