Parallel loss of presynaptic and postsynaptic dopamine markers in normal aging.
Aging of the human brain is associated with a decline in dopamine (DA) function, generally interpreted as reflecting DA cell loss. Positron emission tomography studies revealed that in healthy individuals, the age-related losses in DA transporters (presynaptic marker) were associated with losses in D2 receptors (postsynaptic marker) rather than with increases as is known to occur with DA cell loss. This association was specific for DA synaptic markers, because they were not correlated with striatal metabolism. Furthermore, the association was independent of age, suggesting that a common mechanism regulates the expression of receptors and transporters irrespective of age.
Volkow
N D
ND
Medical Department, Brookhaven National Laboratory, Upton, NY 11973, USA.
Wang
G J
GJ
Fowler
J S
JS
Ding
Y S
YS
Gur
R C
RC
Gatley
J
J
Logan
J
J
Moberg
P J
PJ
Hitzemann
R
R
Smith
G
G
Pappas
N
N
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D015415:Biomarkers / Q000032:analysis; D002352:Carrier Proteins / Q000378:metabolism*; D003342:Corpus Striatum / Q000000981:diagnostic imaging / Q000378:metabolism; D004298:Dopamine / Q000502:physiology*; D005260:Female; D005947:Glucose / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D017448:Receptors, Dopamine D2 / Q000032:analysis*; D017661:Receptors, Presynaptic / Q000502:physiology*; D014055:Tomography, Emission-Computed
D015415:Biomarkers; D002352:Carrier Proteins; D017448:Receptors, Dopamine D2; D017661:Receptors, Presynaptic; D005947:Glucose; D004298:Dopamine