They can ameliorate cognitive impairment through paracrine or immunomodulatory effects, and their effector molecules are also neurotransmitters and cytokines, such as GABA, IL-10, and BDNF (Perets et al., 2017; Tsivion-Visbord et al., 2020; You et al., 2020). Here, BDNF is linked to Cognitive impairment.