GHRL and Parkinson disease: It is worth mentioning that during the searching phase of thisreview, many other papers were found to investigate similar neuraleffects of ghrelin on other brain disorders, such as chronic unpredictablemild stress, passive avoidance memoryimpairment, and chronic social defeatstress. The findings from this reviewshowed that ghrelin (or AG) is significantly promising for the treatmentof AD and PD.