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 alpha-[(11)C]methyl-L: -tryptophan (alpha-[(11)C]MTrp) trapping rate constant (K*; microl.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 alpha-[(11)C]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 alpha-[(11)C]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.
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 alpha-[(11)C]methyl-L: -tryptophan (alpha-[(11)C]MTrp) trapping rate constant (K*; microl.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 alpha-[(11)C]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 alpha-[(11)C]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.
Authors: Karen H Adams; Lars H Pinborg; Claus Svarer; Steen G Hasselbalch; Søren Holm; Steven Haugbøl; Karine Madsen; Vibe Frøkjaer; Lars Martiny; Olaf B Paulson; Gitte M Knudsen Journal: Neuroimage Date: 2004-03 Impact factor: 6.556
Authors: Csaba Juhász; Diane C Chugani; Uma N Padhye; Otto Muzik; Aashit Shah; Eishi Asano; Tom J Mangner; Pulak K Chakraborty; Sandeep Sood; Harry T Chugani Journal: Epilepsia Date: 2004-02 Impact factor: 5.864
Authors: J I Nurnberger; M C Blehar; C A Kaufmann; C York-Cooler; S G Simpson; J Harkavy-Friedman; J B Severe; D Malaspina; T Reich Journal: Arch Gen Psychiatry Date: 1994-11
Authors: David O Kamson; Tiffany J Lee; Kaushik Varadarajan; Natasha L Robinette; Otto Muzik; Pulak K Chakraborty; Michael Snyder; Geoffrey R Barger; Sandeep Mittal; Csaba Juhász Journal: J Nucl Med Date: 2014-09-04 Impact factor: 10.057
Authors: Cynthia A Munro; Clifford I Workman; Elisse Kramer; Carol Hermann; Yilong Ma; Vijay Dhawan; Thomas Chaly; David Eidelberg; Gwenn S Smith Journal: Synapse Date: 2012-08-28 Impact factor: 2.562