GH1 and Parkinson disease: Abbreviations: Nav1.5, voltage-gated sodium channel isoform 1.5; ASIC, acid-sensing ion channel; NHE1, Na+/H+ exchanger isoform 1; MS: Multiple sclerosis; NHE1, Na+/H+ exchanger isoform 1; AM, amiloride; CP, cariporide; 4-AP, aminopyridine; NM, nafamostat mesylate; GFs, growth factors; PDGF, platelet-derived growth factors; PD, Parkinson’s disease; hGH: human growth hormone; AD, Alzheimer’s disease; ALS, amyotrophic lateral sclerosis; CSF, cerebrospinal fluid.