Effect of ageing on the cerebral hemodynamics in the marmoset monkey
Résumé
Aim
Cerebrovascular function declines during normal ageing and appears to be closely linked to brain function
alteration in the elderly. We adapted dedicated MRI sequences to analyze blood flow dynamics in arterial and
venous intracranial vessels, using a non-human primate model of significant interest for preclinical research, the
marmoset monkey Callithrix jacchus.
Methods
Imaging sequences were acquired on a 7T MRI (Bruker Biospec, voxel size: 0,15x0,15X1mm3) on two groups of
male and female marmosets: 10 young (4 years old) and 9 aged (9 years old). Internal carotid arteries, basilar
artery, superior and inferior sagittal sinuses were first identified by Time Of Flight (TOF) sequences and flow
velocity in these different vessels was recorded by Phase Contrast (PC) MRI synchronized with ECG signal.
Results
The main significant results show that during the cardiac cycle:
-The blood flow peaks earlier in the basilary trunk than in the carotids.
-The arterial flow peak occurs earlier in the aged than in the young marmoset brains.
-The time interval between the arterial- and the venous flow peaks is shorter in old than in young marmosets.
Conclusions
These results reflect vessel rigidity and tissue compliance changes occurring during ageing in the vascular
network. They have not been shown in human studies, in which blood flow dynamics are usually synchronized
with peripheral pulse measured on the fingertip. They suggest that the time courses of the different vascular
flows could contribute as early markers of brain ageing and brain pathologies.
Domaines
Sciences du Vivant [q-bio]Origine | Fichiers produits par l'(les) auteur(s) |
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