Activin A maintains cerebral cortex neuronal survival and increases voltage-gated Na^+ neuronal current

Activin A, which was first described in 1986, has been shown to maintain hippocampal neuronal survival. Activin A increases intracellular free Ca2＋ via L-type Ca2＋ channels. Our previous study showed that activin A promotes neurite growth of dorsal root ganglia in embryonic chickens and inhibits nitric oxide secretion. The present study demonstrated for the first time that activin A could maintain cerebral cortex neuronal survival in vitro for a long period, and that activin A was shown to increase voltage-gated Na＋ current （/Na） in Neuro-2a cells, which was recorded by patch clamp technique. The present study revealed a novel mechanism for activin A, as well as the influence of activin A on neurons by regulating expressions of vasoactive intestine peptide and inducible nitric oxide synthase.

Expression of c-Fos protein and nitricoxide synthase in neurons of cerebral cortex from fetal rats in hypoxia and protective role of Angelica sinensis

BACKGROUND： Both c-Fos protein and nitricoxide synthase （NOS） have been used as general indexes in relative research about neurons, but it is lack of reports that c-Fos protein and NOS are applied synchronously to study the neurons of hypoxic fetal rats in uterus. OBJECTIVE： To study the effect of hypoxia in uterus on the expression of c-Fos protein and NOS in neurons of cerebral cortex from fetal rats and whether Angelica sinensis has the protective effect on these neurons in hypoxia. DESIGN： Randomized control experiment.SETTING ： Department of Histology and Embryology, Luzhou Medical College.MATERIALS ： Twelve adult female Wistar rats in oestrum and 1 male Wistar rat with bodymass from 220 to 250 g were chosen. Parenteral solution of Angelica sinensis mainly contained angelica sinensis, 10 mL/ampoule, was provided by Department of Agent of the Second Hospital Affiliated to Hubei Medical University （batch number： 01062310）. METHODS ： This experiment was completed in the Department of Histology and Embryology of Luzhou Medical College from September 2003 to June 2004. ①Twelve adult female Wistar rats in oestrum and 1 male Wistar rat were housed in one rearing cage. Vaginal embolus was performed on conceive female rat at 8： 00 am next day. On the 15^th conceiving day, all conceiving rats were divided randomly into three groups： control group, hypoxia group and Angelica group with 4 in each group. Rats in hypoxia group and Angelica group were modeled with hypotonic hypoxia in uterus. Angelica group： Rats were injected with 8 mL/kg Angelica sinensis injection through caudal veins before hypoxia. Hypoxia group： Rats were injected with the same volume of saline. Control group： Rats were not modeled and fed with normal way. ② Twenty embryos of rats were chosen randomly from each group and then routinely embedded in paraffin. Paraffin sections were cut from the brain of embryos to anterior fontanelle. Double-label staining was used to detect the expression of nNOS and c-Fos in neurons of cerebral cortex from embryos of rats. OLYMPUS Bx-50 microscope was used to observe sections and DP12 digit camera was also used under 400 times to detect types of cells. Under microscope, the number of c-Fos, NOS, c-Fos/NOS positive neurons in cerebral cortex from embryos of rats were counted in 2 fields with magnification of 400 in one section per animal. ③ The data in experiments were analyzed by one-way analysis of variance （ANOVA） followed by q test. MAIN OUTCOME MEASURES： ① Results of immunohistochemical double-label staining of c-Fos/NOS from cerebral cortex; ② Comparison of amount immunohistochemical double-label staining of c-Fos/NOS positive cells from cerebral cortex. RESULTS：① The positive NOS cells and c-Fos/NOS cells in the three groups were mainly distributed in cerebral cortex, but positive c-Fos neurons were not observed. ② Positive NOS cells and c-Fos/NOS cells in hypoxia group were more than those in control group （76.55±12.02, 50.45±10.39; 33.35±7.42, 26.35±6.67, P 〈 0.05）, but those in Angelica group were less than those in hypoxia group （51.70±9.82, 35.65±8.37, P 〈 0.05）. CONCLUSION： Hypoxia can stimulate the increase of expression of c-Fos protein and NOS in neurons of cerebral cortex. However, Angelica sinensis can decrease this expression so as to play a protective role in cerebral neurons of hypoxic fetal rats.

Effects of Electroacupuncture on Hippocampal and Cortical Apoptosis in A Mouse Model of Cerebral Ischemia-reperfusion Injury

Objective: To observe the effects of electroacupuncture on hippocampal and cortical apoptosis in a mouse model of cerebral ischemia-reperfusion injury. Methods: Mouse models established by repeated cerebral ischemia-reperfusion, followed by electroacupuncture at Shenshu, Geshu, and Baihui points. The control group mice were intragastrically administered Hydergine. On day 1 and 7 post-treatment, hippocampal and cortical apoptosis was detected by terminal-deoxynucleotidyl transferase mediated dUTP nick-end labeling (TUNEL), and apoptosis images in the hippocampal CA1 zone and cortical area were analyzed. Results: In the model group, apoptotic cells were detected one day after treatment and some cellular fibers were disarrayed. By day 7 post-treatment, there was an increase in the number of apoptotic cells in the hippocampal CA1 region. In addition, there were apoptotic cells in the cortical area, the cortical layers were thinner with localized neuronal loss and sieve-like lymphocyte infiltration, as well as glial cell proliferation and visible infarct lesions. However, in the Hydergine and electroacupuncture groups, there was a small number of apoptotic cells. At 7 days post-treatment in the model group, field number, numerical density on area, and surface density were increased. However, in the Hydergine and electroacupuncture groups these parameters were decreased (P<0.01), with a significant difference between the two treatment groups (P<0.01). Conclusion: Electroacupuncture treatment inhibited apoptosis and provided neuroprotection.