Naslov
Brain regional α -[11C]methyl-L-tryptophan trapping in healthy adults: absence of an age effect

Autori
Rosa-Neto, P. ; Benkelfat, C. ; Sakai, Y. ; Leyton, M. ; Morais, J.A. ; Dikšić, Mirko

Izvornik
European Journal of Nuclear Medicine & Molecular Imaging (1619-7070) 34 (2007), 8; 1254-1264

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Positron emission tomography . 5-HT. á-MTrp

Sažetak
Purpose Previous functional neuroimaging studies suggest that selective aspects of the brain serotonin (5-HT) system change during the aging process. Here, we assessed the effects of aging on the brain regional á-[11C]methyl-L-tryptophan (á-[11C]MTrp) trapping rate constant (K* ; ì l· g.1· min.1), which, with certain assumptions, could be taken as a proxy of 5-HT synthesis. Methods Thirty-six healthy right-handed subjects had positron emission tomography (PET) scans following injection with á-[11C]MTrp [18 males aged 46.6± 22.2 years (range 20– 80 years) and 18 females aged 33.0± 15.5 years (range 20– 80 years)]. The trapping rate constant, K*, was calculated with the graphical method for irreversible ligands using the sinus-venous input function. A priori selected volumes of interest (VOIs) were defined using an automatic algorithm. Results VOI analysis showed no correlation between age and brain regional K* values. As reported by others, significant age-related reductions of gray matter were observed in the thalamus and frontal and cingulate cortices ; even with partial volume correction there was still no significant relationship between K* and age. Further exploratory SPM voxelwise correlation between age and á-[11C]MTrp trapping, using p=0.05 (uncorrected), as well as voxel-based morphometry, was in agreement with the VOI analysis. Conclusion The dissociation between age-related changes in brain anatomy and this index of serotonin synthesis suggests independent mechanisms underlying the normal aging process.

Izvorni jezik
Engleski

Znanstvena područja
Temeljne medicinske znanosti

POVEZANOST RADA