Macroscopic brain region and network changes in a central-arterial-stiffness rat model

Area of Science:

• Neuroscience
• Cardiovascular Science
• Medical Imaging

Background:

• Cardiovascular disease is a significant risk factor for dementia.
• The precise mechanisms by which cardiovascular abnormalities affect brain structure are not fully understood.

Purpose of the Study:

• To investigate the effects of central arterial stiffness on brain structure.
• To explore the relationship between arterial stiffening and changes in the hippocampus and related neural networks.

Main Methods:

• Development of a rat model with central arterial stiffness induced by aortic arch calcification using calcium chloride.
• Utilized ex vivo magnetic resonance imaging (MRI), including diffusion tensor imaging (DTI), to analyze brain microstructure and structural connectome.
• Compared brain volume, microstructural integrity, and neural connectivity between model and control animals.

Main Results:

• The rat model exhibited central arterial stiffness without significant changes in overall brain volume.
• Ex vivo DTI revealed microstructural alterations within the limbic region, specifically the hippocampus.
• Whole-brain structural connectome analysis demonstrated altered neural connections, particularly in hippocampal-related networks.

Conclusions:

• Central arterial stiffness can directly induce structural changes in the limbic system, including the hippocampus.
• These findings suggest a direct mechanistic link between arterial stiffening and brain alterations relevant to dementia.
• The study highlights the importance of cardiovascular health in maintaining brain integrity.