Effects of acupuncture on the spontaneous discharge of nerve cells and levels of monoamine neurotransmitters in ventromedial nucleus of hypothalamus (VMH) of the obese rats were investigated. Results indicated that the levels of tyrosine (Tyr) and dopamine (DA) were lowered, the levels of 5-hydroxytryptamine (5-HT) and 5-hydoxyindole acetic acid (5-HIAA) increased, and the frequency of the spontaneous discharge of nerve cells in VMH lowered in the obese rat group as compared with the normal group. When acupuncture obtained the effect of weight reduction, the frequency of spontaneous discharges of nerve cells in VMH were markedly increased, and the levels of Tyr, DA and tryptamine (Typ) and 5-HT/5-HIAA ratio elevated, and the 5-HT level lowered. It is suggested that the virtuous regulative action of acupuncture on VMH might be one of the key factors in acupuncture for weight reduction.

Green tea polyphenols are strong antioxidants and can reduce free radical damage. To investigate their neuroprotective potential, we induced oxidative damage in spinal cord neurons using hy-drogen peroxide, and applied different concentrations (50-200 μg/mL) of green tea polyphenol to the cell medium for 24 hours. Measurements of superoxide dismutase activity, malondial-dehyde content, and expression of apoptosis-related genes and proteins revealed that green tea polyphenol effectively alleviated oxidative stress. Our results indicate that green tea polyphenols play a protective role in spinal cord neurons under oxidative stress.

Emerging studies of treating spinal cord injury (SCI) with adult stem cells led us to evaluate the effects of transplantation of hair fol icle stem cells in rats with a compression-induced spinal cord lesion. Here, we proposed a hypothesis that rat hair fol icle stem celltransplantation can promote the recovery of injured spinal cord. Compression-induced spinal cord injury was induced in Wistar rats in this study. The bulge area of the rat vibrissa fol icles was isolated, cultivated and characterized with nestin as a stem cellmarker. 5-Bromo-2′-deoxyuridine (BrdU) labeled bulge stem cells were transplanted into rats with spinal cord injury. Immunohistochemical staining results showed that some of the grafted cells could survive and differentiate into oligodendrocytes (receptor-interacting protein positive cells) and neuronal-like cells (βIII-tubulin positive cells) at 3 weeks after transplantation. In addition, recovery of hind limb locomotor function in spinal cord injury rats at 8 weeks fol owing celltransplantation was assessed using the Basso, Beattie and Bresnahan (BBB) locomotor rating scale. The results demon-strate that the grafted hair fol icle stem cells can survive for a long time period in vivo and differentiate into neuronal- and glial-like cells. These results suggest that hair fol icle stem cells can promote the recovery of spinal cord injury.

The experimental model of traumatic brain injury was established in Sprague-Dawley rats according to Feeney’s free fal ing method. The brains were harvested at 2, 6 and 24 hours, and at 3 and 5 days after injury. Changes in brain water content were determined using the wet and dry weights. Our results showed that water content of tissue significantly increased after traumatic brain injury, and reached minimum at 24 hours. Hematoxylin-eosin staining revealed pathological impairment of brain tissue at each time point after injury, particularly at 3 days, with nerve celledema, degenera-tion, and necrosis observed, and the apoptotic rate significantly increased. Immunohistochemistry and western blot analysis revealed that the expression of occludin at the injured site gradual y de-creased as injury time advanced and reached a minimum at 3 days after injury; the expression of connexin 43 gradual y increased as injury time advanced and reached a peak at 24 hours after in-jury. The experimental findings indicate that changes in occludin and connexin 43 expression were consistent with the development of brain edema, and may reflect the pathogenesis of brain injury.

骨髓基质细胞诱导分化为神经细胞的研究进展

骨髓基质细胞(BMSCs)在诱导剂的作用下在体外可以定向分化为神经元样细胞,但尚未在临床上广泛使用,主要的原因是神经元样细胞的数量和纯度不够.在骨髓基质细胞诱导分化为神经元样细胞的研究中,诱导剂的选择是关键,目前常见的诱导剂有β-巯基乙醇、细胞因子等.近年来发现利用中药也可以进行诱导分化.

肥厚性幽门狭窄肽能神经的免疫组化研究

本文应用免疫组织化学技术,对20例幽门狭窄患儿的脑啡肽、P物质和血管活性肠肽三种肽能神经在幽门组织中的数量和分布进行了观察.发现三种肽能神经纤维在患儿环肌层中有改变,提示肽能神经数量和分布异常与发病有关.本文亦讨论了本病的发病机理.