BDNF and Parkinson disease: The dysregulation of BDNF-TRKB signaling through aberrant upregulation of the TRKB-T1 isoform has been implicated in various human diseases and dysfunctions, particularly neurological and psychiatric disorders, including Alzheimer’s disease (AD), Parkinson’s disease (PD), Amyotrophic Lateral Sclerosis (ALS) and Frontotemporal dementia (FTD), Huntington’s disease (HD), epilepsy, stroke, mood disorders and schizophrenia [8].