The purpose of this study was to investigate the effects of Rhodiola rosea extract and depression on the serotonin (5-HT) level, cell proliferation and quantity of neurons at cerebral hippocampus ofdepressive rats induced by Chronic Mild Stress (CMS). Seventy male Sprague-Dawley rats were divided into seven groups (10 per group): normal control group, untreated depressive rat model group, negative control group, positive control group, low dosage Rhodiola rosea extract (1.5g/kg) group, medium dosage Rhodiola rosea extract (3g/kg) group and high dosage Rhodiola rosea extract (6g/kg) group. After the depressive rats induced by CMS had received Rhodiola rosea extract for 3 weeks, the 5-HT levels at cerebral hippocampus were detected by high performance liquid chromatography. Bromodeoxyuridine (BrdU) was injected in vivo to label the proliferating cells at hippocampus, and morphometry was used to count the hippocampal neurons. The results showed that the 5-HT level of the three experimental groups had recovered to normal status. The immunohistochemistry of hippocampus BrdU positive cells had returned to the normal level in the group of depressive rats with low dosage Rhodiola rosea extract. In conclusion the results demonstrated that Rhodiola rosea extract could improve 5-HT level in hippocampus in depressive rats, and low dosage Rhodiola rosea could induce neural stem cell proliferation at hippocampus to return to normal level, repairing the injured neurons at hippocampus.

To investigate the synergistic effect of Schwann cells (SCs) and retinoic acid (RA) on differentiation andsynaptogenesis of neural stem cells (NSCs) derived from hippocampus of neonatal rats. Methods The classical methodfor 2

To explore therapeutic potential of engineered neural tissue, we combined genetically modified neural stem cells (NSCs) and poly(lactic acid-co-glycolic acid) (PLGA) polymers to generate an artificial neural network in vitro. NSCs transfected with either NT-3 or its receptor TrkC gene were seeded into PLGA scaffold. The NSCs were widely distributed and viable in the scaffold after culturing for 14 days. Immunoreactivity against Map2 was detected in >70% of these grafted cells, suggesting a high rate of differentiation toward neurons. Immunostaining of synapsin-I and PSD95 revealed formation of synaptic structures, which was also observed under electron microscope. Furthermore, using FM1-43 dynamic imaging, synapses in these differentiated neurons were found to be excitable and capable of releasing synaptic vesicles. Taken together, our artificial PLGA construct permits NSCs to differentiate toward neurons, establish connections and exhibit synaptic activities. These findings provide a biological basis for future application or transplantation of this artificial construct in neural repair

AbstractWe have constructed a recombinant adenovirus expression vector carrying the human neurotrophin-3 (NT-3) receptor TrkC (tyrosine proteinkinase C) gene (rAd-TrkC; 2478 bp) and confirmed the expression of the encoded TrkC in green fluorescent protein (GFP)-murine neural stem cells (NSCs) by reverse transcription polymerase chain reaction (RT-PCR),Western blot analysis, andimmunocytochemistry. The activity of the expressedrAd-TrkC was verified in vitro by evaluating dose-related responses of NSCs to NT-3, a TrkC specific ligand. TrkC-GFP-NSCs had a significantly higher percentage of neuronal differentiation when treated with NT-3 relative to the rAd-LacZ control cells (55.2% vs. 29.8%; P<0.05, χ2 test).Thus, our rAd-TrkC vector can transfect NSCs and produce functional TrkC receptors to promote neuronal differentiation of NSCs.

An animal model oftransected spinal cord injury (SCI) was used to test thehypothesis that cografted neural stem cells (NSCs) and NT-3-SCs promote morphologic andfunctional recoveries of injured spinal cord.Objective: To explore whether cotransplant ofNSC s and NT-3-SCs could promote the injured spinal cord repair. Setting: Zhongshan Medical College, Sun Yat-sen University, PR China. Methods: Female Sprague-Dawley (SD) rats weighing on 200-220g were used to prepare SCI models. The spinal cord was transected between T9 and T10, then NSCs, SCs