ADRB2 and Cognitive impairment: Conversely, other studies have demonstrated that treatment with highly selective β2-AR agonists such as clenbuterol can reduce Aβ levels, promote hippocampal neurogenesis, enhance synaptic plasticity, and improve neuronal death and microglial inflammation (Chai et al., 2016, 2017), whereas application of ICI-118551 exacerbates Aβ and tau neuropathology and cognitive deficits (Branca et al., 2014; Wu et al., 2017).