In the CNS, ghrelin also plays these important roles, which has been verified experimentally in animal models of cerebral ischemia, traumatic brain injury, acute spinal cord injury, epilepsy, Parkinson’s disease, and Alzheimer’s disease (Moon et al., 2009; Lee et al., 2010; Portelli et al., 2012; Kenny et al., 2013; Cecarini et al., 2016; Shi et al., 2017b). The gene discussed is GHRL; the disease is Alzheimer disease.