Abbreviations: 6-hydroxydopamine, (6-OHDA); adeno-associated virus, (AAV); Alzheimer’s disease, (AD); amyotrophic lateral sclerosis, (ALS); brain derived neurotrophic factor, (BDNF); Core Program for Intracerebral Transplantations, (CAPIT); central nervous system, (CNS); ciliary neurotrophic factor, (CNTF); cerebrospinal fluid, (CSF); dopamine, dopaminergic, (DA); deoxyribonucleic acid, (DNA); ...