Protective Effects of 17β-Estradiol on Hippocampal Myelinated Fibers in Ovariectomized Middle-aged Rats.

Estrogen replacement therapy (ERT) improves hippocampus-dependent cognition. This study investigated the impact of estrogen on hippocampal volume, CA1 subfield volume and myelinated fibers in the CA1 subfield of middle-aged ovariectomized rats. Ten-month-old bilaterally ovariectomized (OVX) female rats were randomly divided into OVX + E2 and OVX + Veh groups.

Running exercise protects against myelin breakdown in the absence of neurogenesis in the hippocampus of AD mice.

Neurogenesis might influence oligodendrogenesis and selectively instruct myelination in the mammalian brain. Running exercise could induce neurogenesis and protect the myelin sheaths in the dentate gyrus of AD mice. It is unclear whether running exercise can protect myelin sheaths in the absence of neurogenesis in the hippocampus of AD mice.

Effects of estrogen replacement therapy on the myelin sheath ultrastructure of myelinated fibers in the white matter of middle-aged ovariectomized rats.

The effects of estrogen replacement therapy (ORT) on white matter and the myelin sheath ultrastructure in the white matter of middle-aged ovariectomized (OVX) rats were investigated in this study. Middle-aged rats were ovariectomized and divided into a placebo replacement (OVX + O) group and an estrogen replacement (OVX + E) group. Then, the Morris water maze, electron microscope techniques, and stereological methods were used to investigate the effects of ORT on spatial learning capacity, white matter volume and the myelin sheath ultrastructure in the white matter.

Exercise Prevents Cognitive Function Decline and Demyelination in the White Matter of APP/PS1 Transgenic AD Mice.

Background: Whether exercise could delay the cognitive function decline and structural changes in Alzheimer's disease (AD) are not fully understood.

Methods: 6-month-old male APP/PS1 double transgenic mice ran four months and then the effects of exercise on the cognitive function and the white matter of AD were investigated.

Results: The mean escape latency of the excercised group was significantly shortened when compared to that of the sedentary group.

17β-estradiol replacement therapy protects myelin sheaths in the white matter of middle-aged female ovariectomized rats: a stereological study.

Many studies have shown that estrogen replacement therapy (ERT) can improve cognitive function and affect the structure of the brain, including the white matter, in postmenopausal women. However, it is unclear whether ERT plays an important role in white matter remodeling in postmenopausal women. In the present study, middle-aged (9-12-month-old) female Sprague-Dawley rats were bilaterally ovariectomized (OVX) and randomly allocated to the vehicle treatment (OVX+Veh) group or the 17β-estradiol replacement (OVX+E) group.

Running Exercise Reduces Myelinated Fiber Loss in the Dentate Gyrus of the Hippocampus in APP/PS1 Transgenic Mice.

To investigate the effect of running exercise on myelinated fibers in the dentate gyrus (DG) of the hippocampus during Alzheimer's disease (AD), 6-month-old male APP/PS1 transgenic mice were randomly assigned to control or running groups. The running group mice were subjected to a running protocol for four months. The behaviors of the mice from both group mice were then assessed using the Morris water maze, and the total volume of the DG and the related quantitative parameters with characteristics of the myelinated nerve fiber and the myelin sheath in the DG were investigated using unbiased stereological techniques and electron microscopy.