<unk> 2 has been shown to contribute to many clinical neurological disorders including drug addiction, mood disorders, and stress, as well as Parkinson's disease and Alzheimer's disease. Parkinson's disease Studies indicate<unk> 2 mRNA is present in all cell groups damaged by Parkinson's disease (PD); these findings have identified<unk> 2 as a target for preventing Parkinson's.<unk> 2 presence does not independently protect neurons from PD, but a decrease in<unk> 2 expression has been shown to correlate with susceptibility to the disease, which may be due to a ratio between the dopamine transporter and<unk> 2. Based on the understanding the increased cytosolic dopamine levels lead to dopaminergic cell death in PD, it has been proposed that regulatory polymorphisms in<unk> 2 affect<unk> 2 quantitative expression, and may serve as a genetic risk factor for PD. Specifically, the SLC18A2 promoter region for the<unk> 2 gene has been identified as an area where several polymorphisms form discrete haplotypes. Mood disorders Studies using a genetic rodent model to understand clinical depression in humans suggest that<unk> 2 genetic or functional alterations may be involved in depression. Reduced<unk> 2 levels were identified in specific subregions of the striatum involved in clinical depression, including the nucleus accumbens shell but not the core, the ventral tegmental area, and the substantia nigra's pars compacta. The reduced<unk> 2 protein levels were not accompanied by similar levels of<unk> 2 mRNA alterations. Based on these findings, it has been proposed that<unk> 2 activity is not altered at the level of genetic expression, but may be altered at the functional level in ways that may correlate with clinical depression. Drug addiction Many psychostimulant drugs are known to interact with<unk> , including amphetamine analogs such as methamphetamine, cocaine, and ecstasy (MDMA).
Vesicular monoamine transporter
Glutamate transporter
Neurotransmitter transporter
Norepinephrine transporter
Mechanosensitive channels
Thiamine transporter 1
Acetylcholinesterase
Cyclic nucleotide–gated ion channel