AIM: To investigate the mechanism that antioxidants TA9901, inhibit the formation of amyloid-?-protein(A?) fibril. METHODS: Fourier-transform infrared spectroscopy was used to study the secondary structure changes on aging A? in vitro. RESULTS: A? aged alone for 30 min, the content of ?-pleated sheet and ?-turn were 43.17% and 32.9% respectively. A? aged alone for 7 days, the content of ?-pleated sheet increased abuot 10% and produced a shift of random coil toward ?-pleated sheet. TA9901 induced a significant decrease of the content of ?-turn (23.5%) and ?-pleated sheet (26.4%). VE mainly decreased the ?-pleated sheet content (30.8%). The combination of TA9901 and VE promoted transition of ?-turn (16.7%) toward ?-helix and random coil. CONCLUSIONS: Both of TA9901 and VE can effectively diminish the ?-structural content. TA9901 showed more intensitive inhibition than VE. The effect of TA9901 on the secondary structure of aged A? was associated with the mechanism that TA9901 inhibited A? aggregation and fibril formation.

Objective To investigate the distribution and chemical character of nestin immunoreactive cells in the human basal forebrain. Methods We explored systematically the distribution of nestin immunoreactive cells throughout the human basal forebrain by nestin 331B, 10C2, Rat401 antibody.Furthermore, we investigated the chemical identity of these nestin immunoreactive cells by using double\|labeling immunocytochemistry with NSE, ChAT, p75NGFR, GFAP antibody or using NADPH\|d histochemistry. Results The nestin immunoreactive cells were found in the septum, diagonal band of Broca, innominate substance,amygdala,basal nucleus of Meynert of adult human brain.These nestin immunoreactive cells haven big cell body,2\|3 processes.The nestin immunoreactive cells were labeled by NSE antibody.The large majority of those were single stained,and 28% were double labeled with ChAT positive neurons,15% with NGFR positive neurons,6% with NOS positive neurons.A few nestin immunoreactive cells shared similar morphology with that of astrocyte glia which existed in the spaces between the thin septa pellucida or the midline along the septum.It could not be labeled by GFAP antibody.Conclusion\ A new cluster of nestin immunoreactive neurons that were different from the ChAT,NGFR,NOS positive neurons existed in adult human basal forebrain.\;[

AIM: To investigate the mechanism by which TA9902 inhibits the formation of amyloid ?-peptide (A?) fibrils. METHODS: Fourier-transform infrared spectroscopy was used to study the secondary structure changes on aging A? in vitro. RESULTS: The content of ?-pleated sheet were 46.53% in the condition of A? aged alone for 30 min. When A? aged alone for 72 h, the content of ?-pleated sheet increased about 19.4% and produced a shift of random coil toward ?-pleated sheet. TA9902 induced a significant decrease in the content of ?-pleated sheet (36.09%). CONCLUSION: TA9902 effectively diminishes the ?-pleated structural content. The effect of TA9902 on the secondary structure of aged A? is associated with inhibition of A? aggregation and fibril formation.

Through genetic recombination technique, the rat glial cell line-derived neurotrophic factor (rGDNF) cDNA was in-serted into polylinker site of retroviral vector pLXSN, to generate a recombinant plasmid pLXSN-GDNF as transfer vector. Therecombinant plasmid was verified with restriction analysis, PCR, dot blot hybridization and Southern blot hybridization. The re-sults showed that GDNF cDNA was cloned correctly into retroviral vector pLXSN, recombinant retroviral vector was construct-ed. It is concluded that the eukaryotic cell expression vector was constructed successfully for gene therapy of Parkinson's,Alzheimer's and other central nervous system diseases.

In order to investigate effect of basic fibroblast growth factor(bFGF) on the prolifiration and differentiation of theneural progenitor of embryonic hippocampus of rats in vitro, 25 ng/ml bFGF was employed into the serum-free medium of cultureof hippocampal neural cells of embryonic day 18 rats in the present study. The effect of bFGF on the viability of cells culturedwas detected by MTT colorimetric method and the effects of bFGF on proliferation and differentiation of hippocampal neural pro-genitors were analyzed qualitatively and quantitatively by means of immunochemistry, for the nestin, neurofilament, galactocere-broside and glial acidic fibrillary protein. The results showed that the OD value of experimental group was higher than that ofcontrol group by 1.5 and 1.8 times at 4 d and 8 d respectively. The quantitative analysis of each kinds of cells indicated that thenumber of neural progenitors, neurons and oligodendrocytes in experimental group were increased about 2 times as many as thatin control group, but no differences of astrocytes between the two groups at 4 d. However, the number of four kinds of cells aug-mented about 1.7 times at 8 d. The results of this study suggest that bFGF can not only promote the survival, proliferation, butalso facilitate the differentiation of neural progenitor of hippocampus to neurons and glial cells. To obtain more many purifiedneural progenitors in vitro, the embryonic day 18 is not an appropriate age. It is better to get younger embryo brain to culture and to add enough bFGF.

AIM　To study the effects of Aβ25～35 and Apo E4 on neuronal intracellular free Ca2+(［Ca2+］i). METHODS　Hippocampal and cortical neurons suspension of newborn(0～3 days) SD rats was produced. After incubated with fura-2/AM,the neurons suspension was divided into four groups: control, Aβ25～35, Apo E4, Aβ25～35+Apo E4. Each groups ［Ca2+］i was measured using a RF-5000 dual wavelength spectrofluorometer after incubated with double distilled water, Aβ25～35, Apo E4, Aβ25～35+Apo E4 for 3 min, respectively. The neurons outocorrelation function(ACF) of the scattering light intersity was analyzed by the microscope quasi-elastic light scattering(MQLS) technique The frequency shift line width by ACF. The Γ can sympolize the cell menbrane flilidity. RESULTS　Both Aβ25～35 and Apo E4 could significantly enhance hippocampal and cortical neurons rest ［Ca2+］i, furthermore, the effect of 5 μmol*L-1 Aβ25～35 was higher than the effect of 1 μmol*L-1 Aβ25～35 (P<0.05), and they also amplified KCl-induced rise in ［Ca2+］i in hippocampal and cortical neurons(P<0.05). The interaction of Aβ25～35 and Apo E4 could also significantly enhance hippocampal and cortical neurons rest ［Ca2+］i andamplified KCl-induced rise in ［Ca2+］i in hippocampal and cortical neurons(P<0.05), but they had no synergic or additive effect.The frequency shift line widith Γ of both hippocampal and cortical neurons were decreased by both Aβ25-35 and ApoE4. CONCLUSION　Aβ25～35 and Apo E4 could enhance neuronal intracellular free Ca2+, amd decrease meirpma; ,e,brame f;iodotu. But their interaction had no synergic or additive effect. It suggested that the amplified effect of Aβ25～35 and Apo E4 on neuronal ［Ca2+］i and membane fluidity may be relative to their neurotoxity.

AIM To study the effects of A? 25～35 and Apo E4 on neuronal intracellular free Ca 2+ ([Ca 2+ ] i). METHODS Hippocampal and cortical neurons suspension of newborn(0～3 days) SD rats was produced. After incubated with fura 2/AM,the neurons suspension was divided into four groups: control, A? 25～35 , Apo E4, A? 25～35 +Apo E4. Each groups [Ca 2+ ] i was measured using a RF 5000 dual wavelength spectrofluorometer after incubated with double distilled water, A? 25～35 , Apo E4, A? 25～35 +Apo E4 for 3 min, respectively. The neurons outocorrelation function(ACF) of the scattering light intersity was analyzed by the microscope quasi elastic light scattering(MQLS) technique The frequency shift line width by ACF. The ? can sympolize the cell menbrane flilidity. RESULTS Both A? 25～35 and Apo E4 could significantly enhance hippocampal and cortical neurons rest [Ca 2+ ] i, furthermore, the effect of 5 ?mol?L -1 A? 25～35 was higher than the effect of 1 ?mol?L -1 A? 25～35 ( P

BACKGROUND: The neurons in the medial septum (MS), vertical and horizontal limbs of diagonal band of Broca (vDB and hDB) in the basal forebrain contain rich androgen receptors (ARs) and estrogen receptors (ERs) by which androgen and estrogen can act dramatically on the neurons in the basal forebrain, subsequently affecting learning and memory processes.OBJECTIVE: To qualitatively and quantitatively investigate the effects of androgen replacement therapy on the nitric oxide synthase (NOS)-positive and nestin-positive neurons in the MS, vDB and hDB of castrated adult male rats.DESIGN: A randomly controlled study on experimental animals.SETTING: Department of Anatomy and Brain Research Laboratory of Zhngshan Medical College of Sun Yat-sen University.MATERIALS: The experiment was performed at Department of Anatomy and Brain Research Laboratory of Zhongshan Medical College of Sun Yatsen University from June 2001 to June 2002. Totally twenty-eight adult male Sprague-Dawley rats were randomly divided into four groups with seven rats in each group: androgen replacement therapy for 4 weeks following 24 hours of castration (ART1), androgen replacement therapy for 2 weeks following 2 weeks of castration (ART2), vehicle replacement therapy for 4weeks following 24 hours of castration (VRT), sham-operated group (Sham).INTERVENTIONS: ① ART1 group: The castrated rats received subcutaneous injection of testosterone proprionate (25 mg/kg) dissolved in 100 μL of sterile sesame oil every other day from 10:30 am to 11:00 am for 14 times (4 weeks). ② ART2 group: The castrated rats received subcutaneous injection of testosterone proprionate with the same dosage and method as ART1 group for 7 times (2 weeks). ③ The rats in VRT group received subcutaneous injection of 100μL of sterile sesame oil for 14 times (4 weeks) by the same regime as described above. ④ Rats in Sham group only received sham-operated treatments, and testes were intact and lived for 4 weeks.MAIN OUTCOME MEASURES: Morphology and counts of NOS-positive and nestin-positive neurons were observed in the MS, vDB and hDB with immunohistochemical method at various time points.RESULTS: Data of totally 28 rats were involved in the final analyses. ①Morphological features of both NOS-positive and nestin-positive neurons in the MS, vDB and hDB were not significantly changed among four groups. ② The number of NOS-positive and nestin-positive neurons in the MS and vDB of VRT group were significantly higher than those of Sham group (P＜ 0.05 or 0.01), whereas the numbers of the NOS-positive and nestin-posi-tive neurons in the MS and vDB of ART1 and ART2 groups was significantly lower than those of VRT group (P ＜ 0.05 or 0.01), which nearly reached the levels of sham group (P ＞ 0.05).CONCLUSION: Androgen replacement therapy produces no significant effects on the morphological features of NOS-positive and nestin-positive neurons, but the therapy can selectively decrease the numbers of NOS-positive and nestin-positive neurons in different subregions of the basal forebrain, which may be closely related to androgen downregulation of expressions of NOS and nestin by ARs-mediated mechanisms, thereby producing complex effects on learning and memory processes.

Objective To research the mechanism or pathway through which Substance P(SP) inhibits r-aminobutyric acid(GABA) activated currents in bullfrog dorsal root ganglion(DRG) neurons.Method The experiment was conducted on freshly isolated bullfrog dorsal root ganglion neurons using a whole-cell patch-clamp technique.Results SP could caused a slow inward current when SP was applied to DRG neurons;SP could inhibits GABA-activated currents;The inhibition could be reduced largely when protein kinase C(PKC) inhibiter,1-(5-isoquinolinesulphorry)-2-methylpiperazine(H-7), was dialyzed in cell body.Conclusion The SP ton inhibit GABA-activated currents through protein kinase C.

AIM： To study the pathological relationship of vascular cell adhesion molecule-1 (VCAM-1) expression and monocyte/macrophage infiltration with focal brain ischemia. METHODS: Immunohistochemical technique and focal brain ischemia/reperfusion model were used in the study in order to explore profiles and time-course of VCAM-1 expression and monocyte macrophage (ED2 positive cell) infiltration in ischemic rat brain. RESULTS: VCAM-1 was up-regulated in microvascular endothelial cells in ischemic cortex at 1h postischemia, and continuously expressed during the time of reperfusion. ED2 positive cells infiltrated into ischemic cortex at 1h iscehmia/ 2h reperfusion and then ED2 positive cells increased gradually with the time of reperfusion, ED2 positive cell infiltration showed apparently relationship with VCAM-1 expression, and both of them exhibited the some changes of time-dependence. CONCLUSION: Cerebral ischemia induced VCAM-1 expression and ED2 positive cell infiltration and VCAM-1 may regulate the recruitment of ED2 positive cells in the ischemic brain region. The results suggested that VCAM-1 and ED2 positive cells may be participated in the pathogenesis of cerebral ischemic injury.