{"entity":{"id":"dopamine-transporter","kind":"target","name":"Dopamine transporter (DAT)","aka":["DAT"],"tldr":"A protein on the ends of brain cells that make dopamine, which recycles the dopamine after it has done its job. A scan using a tracer that sticks to this protein can show whether those brain cells are dying, which happens in Parkinson's disease.","summary":"The dopamine transporter sits on the axon terminals of presynaptic nigrostriatal dopaminergic neurons, which project from the substantia nigra to the striatum (caudate and putamen), and terminates dopaminergic signalling by taking dopamine back into the neuron after release. Because DAT density on the neuron surface tracks the number of intact nigrostriatal terminals, loss of DAT signal on imaging is a marker of neurodegeneration rather than a direct marker of disease-specific pathology.\n\nIoflupane I-123 (DaTscan/DATSCAN), a radioiodinated cocaine analogue, binds reversibly to DAT (Ki approximately 0.62 nM) and is imaged by SPECT 3-6 hours after injection, concentrating in the striatum in proportion to transporter density. It is FDA- and EMA-approved as an adjunct for striatal DAT visualisation in adults with suspected parkinsonian syndromes and suspected dementia with Lewy bodies, chiefly to help distinguish essential tremor (normal DAT scan) from Parkinsonian syndromes (reduced striatal DAT), and probable dementia with Lewy bodies from Alzheimer's disease.\n\nAs a target, DAT's strength is a clean anatomical readout (striatal uptake) that reliably separates presynaptic neurodegeneration from tremor of other causes. Its main limitation is lack of specificity between the parkinsonian syndromes themselves: DaTscan cannot distinguish idiopathic Parkinson's disease from multiple system atrophy or progressive supranuclear palsy, since all three cause nigrostriatal terminal loss. A range of common drugs (stimulants, some antidepressants, benztropine) bind DAT with high affinity and can interfere with image interpretation, so they typically need to be stopped before scanning.","asOf":"2026-09-22","links":[{"label":"FDA label: DATSCAN (ioflupane I 123 injection)","url":"https://www.accessdata.fda.gov/drugsatfda_docs/label/2022/022454s010lbl.pdf"},{"label":"FDA medical review, NDA 022454 (mechanism of action)","url":"https://www.accessdata.fda.gov/drugsatfda_docs/nda/2011/022454sOrig1s000MedR.pdf"},{"label":"PMC: clinical utility of dopamine transporter SPECT imaging","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC3812862/"}],"tags":["neurology","Parkinson's disease","transporter"],"related":["i-123"],"indications":[],"sections":[],"technologies":[],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"symbol":"SLC6A3","biology":"A presynaptic membrane transporter on nigrostriatal dopaminergic neuron terminals that recycles dopamine after synaptic release. Its density in the striatum reflects the number of intact dopaminergic terminals, so loss of transporter signal is a marker of the neurodegeneration that occurs in Parkinsonian syndromes and dementia with Lewy bodies.","whereFound":["Substantia nigra pars compacta neuron terminals in the striatum: high physiological expression, lost with nigrostriatal degeneration","Parkinson's disease, multiple system atrophy, progressive supranuclear palsy: reduced striatal DAT signal (not distinguishable from each other by DAT imaging alone)","Essential tremor and dementia unrelated to Lewy body disease: normal DAT signal, used to rule out parkinsonian degeneration"],"targetClass":"other","prevalence":[]},"route":"/targets/dopamine-transporter/","neighbours":{"isotope":[{"id":"i-123","kind":"isotope","name":"Iodine-123","route":"/isotopes/i-123/"}],"opportunity":[{"id":"opp-alpha-synuclein-pet-parkinsons","kind":"opportunity","name":"Alpha-synuclein PET: works for MSA, not for Parkinson's","route":"/opportunities/opp-alpha-synuclein-pet-parkinsons/"}]}}