ABSTRACT
BACKGROUND: It is well known that central noradrenergic system takes part in learning and memory, but there are a few researches focused on the effects of impairing the central noradrenergic system on rat' s P3-like cognitive potential.OBJECTIVE: To study the effects of impairing the central noradrenergic system on rat's P3-like cognitive potential.DESIGN: Randomized controlled study based on the experimental animals.SETTING: Department of physiology in a medical college of a university.MATERIALS: Totally 30 male SD rats, clean degree, weighing from 500 to 600 g, were selected from the Experimental Animal Center of Sun Yat-sen Medical University(certificate: 26-99A018), drank freely and fed timely under the normal condition. After Y-maze test of all the rats, 24 rats with normal learning and memory function, which met the criteria specified in the description of Y-maze test, were randomly divided into three groups(8 rats in each group): control group, 6-oxidopamine (6-OHDA) injection group and saline control group.INTERVENTIONS: The models of central norndrenergic system impairment were made by injecting 6-hydroxysopamine(6-OHDA) into the bilateral dorsal noradrenergic bundle in dentate granule(DG). Then Y-type maze test and elicitation of P3-likewere carried out respectively before and after the models were built.MAIN OUTCOME MEASURES: Main outcome: P3-like latency, total reaction time(TRT) and error number(EN). Secondary outcome: Results of P3-like test recorded in the 12 days after the models were built.RESULTS: As compared with the controls, the model rats' P3-like latency and total reaction time(TRT) prolonged and error number(EN) increased statistically ( P ＜ 0.05 ).CONCLUSION: Central NE takes part in the activities of learning and memory and plays a certain role in the production and integration of P3 -like.
ABSTRACT
AIM: To study the change in cognitive function in derogative state of different neurotransmitter by mensurating P300 amplitude and latency. METHODS: Acetylcholine (ACh) system was disfunctioned by severing fimbrial-fornix(FF) transaction and Norepinephrine (NE) system impaired by injection of 6-hydroxysopamine into the bilateral dorsal noradrenergic bundle in DG. Then Y-type maze test and elicitation of P3-like latency were carried out separately before and after the all models were built. RESULTS: In both experimental groups, P3-like latency was prolonged significantly compared with the control and had positive correlation with indices of Y-maze test(EN,TRT). CONCLUSION: ACh and NE are important in the production and conformity of P300.
ABSTRACT
AIM: To separate and identify the mesenchymal stem cells (MSCs) from human fetal bone and to study their differentiation to hepatocyte like cells under the action of chemical induction.METHODS: The MSCs from human fetal bone were isolated and purified according to the different growth characteristic of attaching to the wall of cell culture flask. The cell cycle and surface markers of MSCs were identified using flow cytometry. The MSCs were pre-induced by adding DMSO, ?-Me and 5-aza for 24 h, then adding the inductive medium of H-DMEM and rh-HGF to induce their differentiation to hepatocyte like cells (HLCs). HLCs were identified by the typical morphological change and the expression of special protein with the method of immunocytochemistry. RESULTS: The MSCs derived from human fetal bone expressed adhesion molecules CD29+, CD44+, but not antigens of hematopoietic CD34, CD45, and not antigens related to GVHD, such as HLA-DR, CD80 and CD86. Exposure of these cells to above-mentioned inductive agents resulted in obvious morphological change and an increase in expression of AFP and ALB. CONCLUSION: The results suggest the existence of plentiful MSCs in human fetal bone. MSCs derived from human fetal bone can easily differentiate to HLCs, and they have a lower immunogenic nature, which may provide the ideal source for tissue engineering (bioartificial liver) for cellular therapeutics.
ABSTRACT
AIM: To observe the relationship between noradrenaline and the synaptic configuration in rat hippocampus CA3 area. METHODS: Noradrenergic system injured models were produced by injecting 6-hydroxydopamine into rats' bilateral dorsal noradrenergic bundle. Then Y-type maze tests and elicitation of P3-like were carried out respectively before and after the model was established. The parameters of synaptic configuration in the hippocampus CA3 areas were also analyzed quantitatively. RESULTS: The decreases in the thickness of postsynaptic density material, the curvature of synaptic interface and the occurrence of perforated synapses, and the increase in the width of synaptic cleft were observed. CONCLUSION: The normal noradrenalin level in hippocampus is necessary to maintain the normal synaptic interface ultrastructure in hippocampus CA3 area.