Elsevier

Experimental Gerontology

Volume 99, 1 December 2017, Pages 69-79
Experimental Gerontology

Volumetric changes in the aging rat brain and its impact on cognitive and locomotor functions

https://doi.org/10.1016/j.exger.2017.09.008Get rights and content
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Highlights

  • Brain volume altered with age in specific regions such as the hippocampus.

  • Locomotor activity, spatial and learning memory impaired in the late-aged rats.

  • Oxidative stress and antioxidant enzyme activity changed with age.

Abstract

Impairments in cognitive and locomotor functions usually occur with advanced age, as do changes in brain volume. This study was conducted to assess changes in brain volume, cognitive and locomotor functions, and oxidative stress levels in middle- to late-aged rats. Forty-four male Sprague-Dawley rats were divided into four groups: 14, 18, 23, and 27 months of age. 1H magnetic resonance imaging (MRI) was performed using a 7.0-Tesla MR scanner system. The volumes of the lateral ventricles, medial prefrontal cortex (mPFC), hippocampus, striatum, cerebellum, and whole brain were measured. Open field, object recognition, and Morris water maze tests were conducted to assess cognitive and locomotor functions. Blood was taken for measurements of malondialdehyde (MDA), protein carbonyl content, and antioxidant enzyme activity. The lateral ventricle volumes were larger, whereas the mPFC, hippocampus, and striatum volumes were smaller in 27-month-old rats than in 14-month-old rats. In behavioral tasks, the 27-month-old rats showed less exploratory activity and poorer spatial learning and memory than did the 14-month-old rats. Biochemical measurements likewise showed increased MDA and lower glutathione peroxidase (GPx) activity in the 27-month-old rats. In conclusion, age-related increases in oxidative stress, impairment in cognitive and locomotor functions, and changes in brain volume were observed, with the most marked impairments observed in later age.

Abbreviations

MRI
magnetic resonance imaging
mPFC
medial prefrontal cortex
MDA
malondialdehyde
GPx
glutathione peroxidase
CAT
catalase
SOD
superoxide dismutase
RF
radio-frequency
TR
repetition time
TE
echo-time
FOV
field of view
UPLC
ultra-performance liquid chromatography

Keywords

Aging
Brain atrophy
MRI
Cognitive function

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