GHRL and Parkinson disease: It has been elucidated that ghrelin acted against or restrained cellular deprivation precipitated by exposure to a pesticide, i.e., rotenone [142,143], upgraded the abnormal rotarod motor performance in the experimental PD mouse model precipitated by subjection to MPTP [133], as well as mediated the nerve cell protective abilities of a nutritional strategy that markedly de-escalates the ingestion of calories without malnourishment, i.e., caloric restriction (CR) [144].