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Aging diminishes cerebral blood volume and vasodilation in rats: non‐invasive absolute measurements by Near Infrared Spectroscopy
Author(s) -
Shaul Merav Esther,
Hallacoglu Bertan,
Fantini Sergio,
Rosenberg Irwin,
Troen Aron
Publication year - 2013
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.27.1_supplement.1186.2
Subject(s) - cerebral blood volume , dementia , hypercapnia , medicine , vasodilation , cardiology , microcirculation , blood volume , ageing , cerebral blood flow , physiology , pathology , respiratory system , disease
Brain microvasculature pathology is common in all forms of dementia, but it is unclear whether it precedes or follows neurodegeneration. Since aging is the strongest risk factor for dementia, we hypothesized that it would be accompanied by pathologic microvascular changes that would be discernible by non‐invasive absolute Near Infrared Spectroscopy (NIRS). We measured longitudinal changes in cerebral blood volume (CBV), at rest and in response to hypercapnia, in Wistar‐Kyoto rats, aged 4 months and one year later in middle‐age. Mean absolute CBV dropped with age from 4.42±0.25 to 2.71±0.17 ml/100gr tissue, reflecting a highly significant 37.7±4.3% age‐related decrease. Vasodilation also decreased with age: In middle‐aged rats, hypercapnia caused CBV to increase by only 0.121±0.044ml above resting values, compared to 0.175±0.027ml in young rats. These findings indicate that such microvascular changes may occur as early as middle age. The ability to detect and measure physiological evidence of structural and functional microvascular pathology during life can help to understand the role of microvascular pathology in dementia.