Modulation of striatal dopamine D1 binding by cognitive processing.
There is strong evidence that dopamine (DA) is implicated in higher-order cognitive functioning, but it remains controversial whether D1 receptor binding can be modified by cognitive activity. We examined striatal D1 binding potential (BP) in 20 younger (22-30 years) and 20 older (65-75 years) persons who underwent two [(11)C] SCH 23390 PET measurements, one while resting and one while performing a cognitive task taxing inhibitory functioning. The younger persons showed significant task-related BP reductions in sensorimotor, limbic, and associative striatum during cognitive activity compared to rest. Older persons showed no reliable BP reductions in any striatal subregion. These findings demonstrate that D1 receptor binding can be modified by cognitive activity in younger persons, but also provide novel evidence for the notion that human aging is associated not only with lower DA receptor density but also with altered modifiability of the DA system.
Karlsson
Sari
S
Aging Research Center, Karolinska Institutet, Gävlegatan 16, SE-113 30 Stockholm, Sweden. sari.karlsson@ki.se
Nyberg
Lars
L
Karlsson
Per
P
Fischer
Håkan
H
Thilers
Petra
P
Macdonald
Stuart
S
Brehmer
Yvonne
Y
Rieckmann
Anna
A
Halldin
Christer
C
Farde
Lars
L
Bäckman
Lars
L
D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D000704:Analysis of Variance; D001552:Benzazepines; D001931:Brain Mapping; D002250:Carbon Radioisotopes; D003071:Cognition / Q000502:physiology*; D003342:Corpus Striatum / Q000000981:diagnostic imaging / Q000502:physiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009483:Neuropsychological Tests; D049268:Positron-Emission Tomography; D017447:Receptors, Dopamine D1 / Q000378:metabolism*; D055815:Young Adult
D001552:Benzazepines; D002250:Carbon Radioisotopes; D017447:Receptors, Dopamine D1; C534628:SCH 23390