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DOI: 10.1055/s-0039-1683515
Prefrontal-thalamic noradrenaline transporter availability is reduced in adults with ADHD
Publication History
Publication Date:
27 March 2019 (online)
Ziel/Aim:
The central noradrenaline (NA) system, which modulates cognitive processes such as attention and working memory, has been implicated in the pathopyhisology of attention-deficit/hyperactivity disorder (ADHD). In particular, the NA transporters (NAT) seems to play a key role in ADHD as a treatment target for prescribed drugs such as methylphenidate and atomoxetine. However, changes of NAT availability have not been described so far in adults with ADHD.
Methodik/Methods:
To explore differences in NAT availability, PET and NAT-selective (S,S)-[11C]-O-methylreboxetine (MRB) were applied (mMR biograph, Siemens) in 18 patients with ADHD (7 females, age 33.4 ± 8.5 years, 487.9 ± 8.3 MBq injected activity) and in 18 age- and sex-matched healthy controls (7 females, age 33.4 ± 7.4 years,468.6 ± 7.5 MBq). The regional distribution volume ratios (DVR) were calculated (VOI analysis) based on the individual PET-MRI data coregistration and a multi-linear reference tissue model with 2 contraints (MRTM2) and the occipital cortex serving as the reference region.
Ergebnisse/Results:
We found lower DVR in patients with ADHD compared with healthy controls in several brain regions, reaching statistical significance in the prefrontal brain regions (e.g., the right dorsolateral prefrontal cortex 1.04 ± 0.04 versus 1.07 ± 0.03, p = 0.01) and the thalamus (right: 1.32 ± 0.09 versus 1.39 ± 0.09, p = 0.02) while most of the other investigated brain regions showed a tendency towards lower DVR values in patients compared with healthy controls.
Schlussfolgerungen/Conclusions:
These initial data are in line with an involvement of NAT in prefrontal cortex that also includes thalamo-cortical circuitries. It is an ongoing study for further exploring of how NA/NAT modulates neuronal (resting-state) activity simultaneously measured by means of functional MR imaging and appropriate behavior as assessed by thorough neuropsychological testing.
*Equal Contribution.
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