神经原性因素对小鼠比目鱼肌胞吞作用的影响

本文报道用辣根过氧化物酶 ( HRP)酶标生化方法探讨神经原性因素对小鼠比目鱼肌胞吞作用的影响及其与肌萎缩的关系。坐骨神经鞘内注射秋水仙素诱发比目鱼肌去神经样改变 ,再用脑提取液处理秋水仙素小鼠比目鱼肌 ;用河豚毒素 ( TTX)毛细管埋藏坐骨神经鞘内 ;另将变性神经提取液注入正常及人工冬眠小鼠的比目鱼肌间隙。测定比目鱼肌 HRP摄取的相对含量及肌肉湿重和总蛋白量。结果表明 ,脑提取液可完全消除秋水仙素引起的胞吞摄取增加和肌肉湿重及总蛋白量的减少。河豚毒素比秋水仙素对肌肉的去神经样影响要小 ,变性神经提取液对正常及人工冬眠小鼠的肌肉胞吞摄取明显增强 ,但肌肉湿重及总蛋白量无显著改变 ,提示在生理情况下 ,脑源性神经营养性生物大分子是维持肌肉胞吞稳态的首要因素 ,正常神经支配的肌肉 ,变性神经产物显著诱导胞吞增强 。

视神经再生机制研究与进展

背景:视神经是广泛用于研究促进或抑制中枢神经系统中轴突再生因素的主要载体之一。目的:对视神经再生机制研究进展予以综述。方法:以“Optic nerve,Axon regeneration,Retinal ganglion cell”为英文检索词,以“视神经,轴突再生,视网膜节细胞”为中文检索词,检索发表在PubMed、CNKI、万方数据库的相关文献。结果与结论:在成年个体中视网膜神经节细胞并不具有再生能力,但是在过去几十年的研究中发现,在适当条件的刺激下,其轴突仍具有部分再生的潜能。通过外周神经片段移植、神经营养性因子治疗、增强眼内炎症反应、阻断轴突生长抑制因子和增强或阻断特定的信号通路等方式,或者将上述方法组合应用,视网膜节细胞轴突可再生通过损伤区域,并延伸视神经全长,通过视交叉准确投射到视觉中枢,建立突触后反应。视神经再生的研究不仅可能帮助患者恢复视觉,而且也有助于其他中枢神经系统损伤治疗的研究。

Overexpression of lentivirus-mediated glial cell line-derived neurotrophic factor in bone marrow stromal cells and its neuroprotection for the PC12 cells damaged by lactacystin

Objective To construct recombinant lentiviral vectors for gene delivery of the glial cell line-derived neurotropnic factor （GDNF）, and evaluate the neuroprotective effect of GDNF on lactacystin-damaged PC12 cells by transfecting it into bone marrow stromal cells （BMSCs）. Methods pLenti6/V5-GDNF plasmid was set up by double restriction enzyme digestion and ligation, and then the plasmid was transformed into Top10 cells. Purified pLenti6/V5-GDNF plasmids from the positive clones and the packaging mixture were cotransfected to the 293FT packaging cell line by Lipofectamine2000 to produce lentivirus, then the concentrated virus was transduced to BMSCs. Overexpression of GDNF in BMSCs was tested by RT-PCR, ELISA and immunocytochemistry, and its neuroprotection for lactacystin-damaged PC12 cells was evaluated by MTT assay. Results Virus stock of GDNF was harvested with the titer of 5.6×10^5 TU/mL. After tmnsduction, GDNF-BMSCs successfully secreted GDNF to supematant with nigher concentration （800 pg/mL） than BMSCs did （less than 100 pg/mL）. The supematant of GDNF-BMSCs could significantly alleviate the damage of PC12 cells induced by lactacystin （10 μmol/L）. Conclusion Overexpression of lentivirus-mediated GDNF in the BMSCs cells can effectively protect PC12 cells from the injury by the proteasome inhibitor.

Beneficial effects of moderate voluntary physical exercise and its biological mechanisms on brain health

This article reviewed the beneficial effects of moderate voluntary physical exercise on brain health according to the studies on humans and animals, which includes improving psychological status and cognitive function, enhancing psychological well-being, decreasing the risks of Alzheimer＇s disease （AD） and dementia, and promoting the effects of antidepressant and anxiolytic. The possible underlying neurobiological mechanisms are involved up-active and down-active pathways. The up-active pathway is associated with enhancements of several neurotransmitters systems afferent to hippocampus, including norepinephrine （NE）, serotonin （5-Hydroxytryptamine, 5-HT）, acetylcholine （ACh） and γ-aminobutyric acid （GABA）. The down-active pathway is mainly concerned with up-regulation of the brain-derived neurotrophic factor （BDNF） and neurogenesis. It is suggested that NE activation via β-adrenergic receptors may be essential for exercise-induced BDNF up-regulation. The possible intracellular signaling pathways of NE-mediated BDNF up-expression may be involved in GPCR-MAPK-PI-3K crosstalk and positive feedback.

Effect of resuscitation after selective cerebral ultraprofound hypothermia on expressions of nerve growth factor and glial cell line-derived neurotrophic factor in the brain of monkey

Objective To investigate the expression of nerve growth factor （NGF） and glial cell line-derived neurotrophic factor （GDNF） in monkeys of resuscitation after selective cerebral ultraprofound hypothermia and blood flow occlusion. Methods The monkeys were immediately removed brain after death in operation of group A （identical temperature perfusion group） and group B （ultraprofound hypothermia perfusion group）. Immunohistochemical technique was used to determine frontal cellular expression of NGF and GDNF. Statistics were analyzed by ANOVA analyses with significance level at P 〈 0.05. Results The expressions of NGF and GDNF in the group B were significantly higher than those in the group A （P 〈 0.05）. Conclusion NGF and GDNF increased significantly in the monkeys of resuscitation after selective cerebral ultraprofound hypothermia and blood flow occlusion. It may be a protective mechanism for neuron survival and neural function recovery.

激素和活性多肽

利用位点定向诱变产生3个突变，即分裂了一个离子对，在Arg-30和Glu-350(P4’)

Effects of P2Y_1 receptor on glial fibrillary acidic protein and glial cell line-derived neurotrophic factor production of astrocytes under ischemic condition and the related signaling pathways

Objective The present study aimed to explore the role of P2Y1 receptor in glial fibrillary acidic protein （GFAP） production and glial cell line-derived neurotrophic factor （GDNF） secretion of astrocytes under ischemic insult and the related signaling pathways. Methods Using transient right middle cerebral artery occlusion （tMCAO） and oxygen-glucose-serum deprivation for 2 h as the model of ischemic injury in vivo and in vitro, immunofluorescence, quantitative real-time reverse transcription-polymerase chain reaction （RT-PCR）, Western blotting, enzyme linked immunosorbent assay （ELISA） were used to investigate location of P2Y1 receptor and GDNF, the expression of GFAP and GDNF, and the changes of signaling molecules. Results Blockage of P2Y1 receptor with the selective antagonist N^6-methyl-2′-deoxyadenosine 3′,5′-bisphosphate diammonium （MRS2179） reduced GFAP production and increased GDNF production in the antagonist group as compared with simple ischemic group both in vivo and in vitro. Oxygen-glucose-serum deprivation and blockage of P2Y1 receptor caused elevation of phosphorylated Akt and cAMP response element binding protein （CREB）, and reduction of phosphorylated Janus kinase2 （JAK2） and signal transducer and activator of transcription3 （STAT3, Ser727）. After blockage of P2Y1 receptor and deprivation of oxygen-glucose-serum, AG490 （inhibitor of JAK2） reduced phosphorylation of STAT3 （Ser727） as well as expression of GFAP; LY294002, an inhibitor of phosphatidylinositol 3-kinase （PI3-K）, decreased phosphorylation of Akt and CREB; the inhibitor of mitogen-activated protein kinase kinase 1/2 （MEK 1/2） U0126, an important molecule of Ras/extracellular signal- regulated kinase （ERK） signaling pathway, decreased the phosphorylation of JAK2, STAT3 （Ser727）, Akt and CREB. Conclusion These results suggest that P2Y1 receptor plays a role in the production of GFAP and GDNF in astrocytes under transient ischemic condition and the related signaling pathways may be JAK2/STAT3 and PI3-K/Akt/CREB, respectively, and that crosstalk probably exists between them.

Obesity promotes oxidative stress and exacerbates blood-brain barrier disruption after high-intensity exercise

Purpose: The purpose of this study was to investigate the effects of obesity and high-intensity acute exercise on oxidant-antioxidant status,neurotrophic factor expression, and blood-brain barrier(BBB) disruption.Methods: Twenty-four healthy, untrained men(12 non-obese(mean 14.9% body fat) and 12 obese subjects(mean 29.8% body fat)) performed20 min of continuous submaximal aerobic exercise at 85% maximal oxygen consumption. Blood sampling was performed to examine the oxidant-antioxidant status(reactive oxygen species(ROS) and superoxide dismutase(SOD)), neurotrophic factors(brain-derived neurotrophic factor(BDNF) and nerve growth factor(NGF)), and BBB disruption(S100β and neuron-specific enolase) before and after acute exercise.Results: The obese group showed significantly higher pre-exercise serum ROS levels and significantly lower pre-exercise serum SOD levels than the non-obese group(p < 0.05). Serum ROS, SOD, BDNF, NGF, and S100β levels were significantly increased post-exercise compared with pre-exercise levels in both the non-obese and the obese groups(p < 0.05). The obese group showed significantly higher serum ROS, BDNF, NGF,and S100β levels post-exercise compared to the non-obese group(p < 0.05).Conclusion: Our study suggests that episodic vigorous exercise can increase oxidative stress and blood neurotrophic factor levels and induce disruption of the BBB. Moreover, high levels of neurotrophic factor in the blood after exercise in the obese group may be due to BBB disruption,and it is assumed that oxidative stress was the main cause of this BBB disruption.

Brain-derived neurotrophic factor(BDNF) as a potential mechanism of the effects of acute exercise on cognitive performance

The literature shows that improvements in cognitive performance may be observed following an acute bout of exercise. However, evidence in support of the biological mechanisms of this effect is still limited. Findings from both rodent and human studies suggest brain-derived neu- rotrophic factor （BDNF） as a potential mechanism of the effect of acute exercise on memory. The molecular properties of BDNF allow this protein to be assessed in the periphery （pBDNF） （i.e., blood serum, blood plasma）, making measurements of acute exercise-induced changes in BDNF concentration relatively accessible. Studies exploring the acute exercise--pBDNF--cognitive performance relationship have had mixed findings, but this may be more reflective of methodological differences between studies than it is a statement about the role of BDNE For example, significant associations have been observed between acute exercise-induced changes in pBDNF concentration and cognitive performance in studies assessing memory, and non-significant associations have been found in studies assessing non-memory cognitive domains. Three suggestions are made for future research aimed at understanding the role of BDNF as a biological mechanism of this relationship： 1） Assessments of cognitive performance may benefit from a focus on various types of memory （e.g., relational, spatial, long-term）; 2） More finegrained measurements of pBDNF will allow for the assessment of concentrations of specific isoforms of the BDNF protein （i.e., immature, mature）; 3） Statistical techniques designed to test the mediating role of pBDNF in the acute exercise-cognitive performance relationship should be utilized in order to make causal inferences.

Acute exercise is associated with specific executive functions in college students with ADHD:A preliminary study

Purpose： The relationship between acute exercise and executive functions in college students with attention deficit hyperactivity disorder （ADHD） has not been clearly established. The purpose of this preliminary study was to examine the difference in cognitive performance between college students with and without ADHD and to explore the effects of acute exercise on multiple aspects of executive functions and on serum brain derived neurotrophic factor （BDNF）. Methods： College students （normal： n = 10; ADHD： n = 10） performed the Stroop Test, Trail Making Test, and Digit Span Test prior to and after an acute exercise intervention. Blood samples were obtained prior to the pre-test cognitive test performance and then again after exercise and prior to the post-test cognitive test performance. Results： Students with ADHD exhibited impaired executive functions, particularly on inhibition. Additionally, while acute exercise improved all aspects of executive functions in those without ADHD, acute exercise only improved inhibitory performance for those with ADHD. Further, BDNF was not influenced by acute exercise regardless of the subjects＇ ADHD status. Conclusion： These results provide preliminary evidence for exercise as a potential adjunct treatment for benefitting inhibition in college students with ADHD.

P2X4 receptor and brain-derived neurotrophic factor in neuropathic pain

Objective:To investigate whether the activation of p38MAPK is involved in the neuropathic pain induced by P2X4 receptor,and the effects of activated P2X4 receptor and p38MAPK on expression of brain-derived neurotrophic factor (BDNF) in the chronic neuropathic pain.Methods:Lumbar intrathecal catheters were chronically implanted in male Sprague-Dawley rats.The right sciatic nerve was loosely ligated proximal to the sciatica's trifurcation at approximately 1.0 mm intervals with 4-0 silk sutures.The microglia inhibitor minocycline,P2X4 antagonist (TNP-ATP) and p38MAPK inhibitor (SB203580) were intrathecally administered every 12 h,3 d post-chronic constriction injury (CCI).Mechanical nociceptive thresholds were assessed with the paw withdrawal threshold (PWT) to von Frey filaments.The expression of P2X4 and BDNF were assessed by both immunohistochemical analysis and RT-PCR.Results:Intrathecal injection of minocycline or TNP-ATP or SB203580 significantly attenuated CCI-induced mechanical allodynia.The time courses of P2X4 receptor and BDNF expression were increased at all points after CCI and reached a peak level on postoperative d 7.Intrathecal injection of minocycline or TNP-ATP or SB203580 markedly suppressed the increase of CCI-induced P2X4 receptor and BDNF expression in the spinal cord.Conclusion:The activation of P2X4 receptor BDNF pathways contributes to neuropathic pain in CCI rats,and the activation of p38MAPK is involved in the neuropathic pain induced by P2X4 receptor.

The complex role of physical exercise and reactive oxygen species on brain

Reactive oxygen species （ROS） are continuously generated during aerobic metabolism and at moderate level. They play a role in redox signaling, but in significant concentration they cause oxidative damage and neurodegeneration. Because of the enhanced sensitivity of brain to ROS, it is especially important to maintain the normal redox state in different types of neuron cells. In last decade it became clear that regular exercise beneficially affects brain function, and can play an important preventive and therapeutic role in stroke, Alzheimer, and Parkinson diseases. The effects of exercise appear to be very complex and could include neurogenesis via neurotrophic factors, increased capillariszation, decreased oxidative damage, and increased proteolyfic degradation by proteasome and neprilysin. Data from our and other laboratories indicate that exercise-induced modulation of ROS levels plays a role in the protein content and expression of brain-derived neurotrophic factor, tyrosinerelated kinase B （TrkB）, and cAMP response element binding protein, resulting in better function and increased neurogenesis. Therefore, it appears that exercise-induced modulation of the redox state is an important means, by which exercise benefits brain function, increases the resistance against oxidative stress, facilitates recovery from oxidative stress, and attenuates age-associated decline in cognition.

The expressions of brain-derived neurotrophic factor and nerve growth factor in purified rat choroid plexus epithelial cells in vitro

Objective： To detect the expressions of brain-derived neurotrophic factor （BDNF） and nerve growth factor （NGF） in purified rat choroid plexus epithelial cells in vitro. Methods： Primary and passage choroid plexus epithelial cells were obtained from newborn, one-day Spragne-Dawley rats. The expressions of BDNF and NGF were measured by qRT-PCR and Western blottingting. The secretions of BDNF and NGF were detected by ELISA. Cell supematants of primary cells, purified cells and passage 1 cells were harvested. Results： The expression of BDNF in the purified cells was significantly lower than that in the primary cells （P〈0.05）, and it in the primary cells and the purified cells was significantly higher than that in the passage 1 cells （P〈0.05）. The expression of NGF was significantly higher in the purified cells than in the primary cells and the passage 1 cells （P〈0.05）. It in the passage 1 cells was significantly higher than that in the primary cells （P〈0.05）. Conclusion： The time of CPECs transplantation for central nervous system diseases should be selected based on their secretory function and features,which could lead to better and more effective treatment.

The neurotrophic factor Artemin promotes the motility and invasiveness of MIA PaCa-2 pancreatic cancer cells

Objective： The aim of this study was to analyze the capacity of Artemin promoting the motility and invasiveness of MIA PaCa-2 pancreatic cancer （PAC） cells. Methods： The PAC cell line MIA PaCa-2 was cultured in vitro and studied using Transwell chamber analysis. The motility and invasiveness ability affected by different concentrations of Artemin and its receptor GFRa3 were determined. Expression level of matrix metalloproteinase-2 （MMP-2）, epithelial cadherin （E-cadherin） were quantitative analysis using RT-PCR and Western blot in MIA PaCa-2 cells stimulated with Artemin and receptor GFRa3. Results： MIA PaCa-2 PAC cell motility and invasiveness was significantly increased with Artemin and its receptor GFRa3 increasing concentrations than control （P 〈 0.01）. 150 ng/mL was the best of both the role of concentration. MMP-2 was increased significantly （t = 6.35, t = 7.32）, while E-cadherin was significantly lower （t = 4.27, t = 5.61）, after affected by the 150 ng/mL Artemin and GFRα3,respectively. The difference was statistically significant compared with the control group （P 〈 0.01）. Conclusion： Artemin and its receptor GFRa3 can promote PAC cell motility and invasiveness ability and contribute to the aggressive behavior. The mechanism may be related to increased expression of MMP-2 molecule and E-cadherin downregulation expression.

Subchronic Administration of Linalool Decreases Depressive-Like Behaviour in Restrained Rats

Objectives： The aim of this study was to investigate the effect of linalool in chronically stressed rats on their behaviour as related to depressive disorders and BDNF （brain-derived neurotropic factor） protein in the hippocampus. Methods： Either Tween 80 or linalool （50, 160, 500 mg/kg） was intraperitonealty administered to rats, daily, for two weeks. Some rats were housed in home cages but the others were induced with chronic restrained stress （15 min daily）. At the end of the treatment, the rats were assessed for depressive-like behaviour using the forced swimming test. At the end of the behaviour test, the animals were immediately decapitated and the hippocampus of each animal was removed for the measurement of the BDNF protein by ELISA. Result： The immobility time was significantly increased （p 〈 0.05） but time of climbing was significantly decreased （p 〈 0.05）. The restrained rats treated with linalool, 500 mg/kg, displayed immobility times less than those of their controls （p 〈 0.05） while these rats showed significantly more climbing than in the control rats （p 〈 0.05）. Linalool showed no effect on the BDNF protein in the hippocampus. Conclusions： linalool decreases behaviour related to depressive disorders but it has no effect on the BDNF protein in chronic restrained stress.

Clinical observation of acupuncture combined with medication for mild-to-moderate depression

Objective:To discuss the clinical efficacy and plausible mechanism of Tiao Yang Qu Xie(regulating Yang to eliminate pathogenic factors)needling method plus paroxetine in treating mild-to-moderate depression.Methods:Sixty-six patients with mild-to-moderate depression were divided into an observation group and a control group using the random number table method,each consisting of 33 cases.Another 25 healthy subjects were recruited as a healthy group.The control group took oral paroxetine tablets for treatment,and the observation group received additional acupuncture treatment 3 times weekly.Both groups underwent 4-week treatment.Before treatment,after 2-week and 4-week treatment,and 2 weeks after treatment(follow-up),the patients were assessed using the Hamilton depression scale-17-item(HAMD-17),self-rating depression scale(SDS),self-rating anxiety scale(SAS),and traditional Chinese medicine(TCM)pattern element identification scale for depression.The two groups each randomly contributed 25 cases to detect the protein content of brain-derived neurotrophic factor(BDNF)before treatment and after 4-week treatment,and compared with the healthy group.Results:After 2-week treatment,the markedly effective and total effective rates were significantly higher in the observation group than in the control group(P<0.05);after 4-week treatment,the observation group significantly surpassed the control group in comparing the markedly effective rate(P<0.05).After 2 and 4 weeks of treatment and at the follow-up,the HAMD-17 total score and sleep disorder factor score were lower in the observation group than in the control group(P<0.05);the anxiety-somatic score was lower in the observation group than in the control group after 2-week treatment(P<0.05).After 2 and 4 weeks of treatment and at the follow-up,the observation group was lower than the control group in comparing the scores of SDS,SAS,and TCM pattern element identification scale for depression(P<0.05).After 4-week treatment,the observation group had an increased serum BDNF protein content,higher than that in the control group(P<0.05)and had no significant difference compared to the healthy group(P>0.05).Conclusion:Compared to the use of oral paroxetine alone,acupuncture plus paroxetine can produce more significant efficacy in treating mild-to-moderate depression and act faster in improving sleep disorder and anxiety-somatic symptoms;increasing the serum BDNF protein content may be a part of the mechanism underlying its antidepressant actions.

Effect of eye acupuncture on the expression of brainderived neurotrophic factor in hippocampus in rats with cerebral ischemia-reperfusion injury

Objective To observe the effects of eye acupuncture on expression of brain-derived neurotrophic factor （BDNF） in the hippocampus of rats after ischemia- reperfusion injury in order to study the mechanisms of eye acupuncture in improving ischemia-reperfusion injury. Methods SD rats were randomly divided into a normal group, a sham-operation group, a model group and an eye acupuncture group, with 8 rats in each. The cerebral ischemia-reperfusion injury model was established by thread occlusion method. Acupuncture at ＂liver＂, ＂upper-jiao＂, ＂lower-jiao＂, and ＂kidney＂ was performed for 20 min in the eye acupuncture group immediateness, 12 h and 23.5 h after the reperfusion. After 24 h of the reperfusion, the neurophysical behaviors were evaluated by Zea Longa neurophysical impairment score; the expression of ischemic hippocampus BDNF mRNA was measured by RT-PCR; the expression of ischemic hippocampus BDNF protein was detected by Western blot technique. Results After reperfusion 24 h, compared with the model group, the neurologic impairment score of the eye acupuncture group decreased significantly （P〈0.01）; the expressions of BDNF mRNA and protein in rat hippocampi after the eye acupuncture therapy were both obviously increased （P〈0.01）. Conclusion The eye acupuncture therapy is beneficial for neurofunctional rehabilitation by promoting the repair of the nerve cell which is induced by increasing hippocampus BDNF expression.

Effects of eye-acupuncture on the expression of brainderived neurotrophic factor in the brain of rats with cerebral ischemia reperfusion

Objective To observe the effects of eye-acupuncture therapy and bodyacupuncture therapy on the expression of brain-deprived neurotrophic factor （BDNF） in rats with cerebral ischemia reperfusion injury （CIRI）. Methods According to random number table, 48 SD rats were randomly divided into 6 groups, including normal control group （group A）, sham operation group （group B）, model group （group C）, eye-acupuncture group （group D）, non-acupoint of eye-acupuncture group （group E） and body-acupuncture group （group F）, eight rats in each group. Artery infarction reperfusion model were prepared by using suture-occluded method. Liver region, upper energizer area, lower energizer area and kidney region were selected in the group D. Acupuncture was carried out at the point located at 3 mm from the acupoint areas in the group E. Qūchí （曲池 LI 11）, Zúsānl （足三里 ST 36） and other acupoints were selected in the group F. Zea Longa scoring method was utilized for scoring the neural functions of rats; real-time PCR was carried out to examine the expression level of BDNF mRNA in the brain 72 h after ischemia reperfusion; western blot was carried out to examine the expression level of BDNF protein in the brain 72 h after ischemia reperfusion. Results The symptoms of neurologic impairments in the rats of the group D were alleviated in comparison to those in the group C （P0.01）, and the difference between the group D and the group F was not statistically significant （P0.05）; Compared with the group C, the mRNA and protein expression levels of BDNF in the brain of rats in the group D and the group F both increased （P0.01）, but the difference between the group D and the group F was not statistically significant （P0.05）. Conclusion The functions of eye-acupuncture and body-acupuncture in improving cerebral ischemia reperfusion injury are similar, and the functional mechanisms for the two different therapies may be related to the up-regulation of BDNF expression in brain and thus promote the repairing of brain tissues.

Function of Ca^(2+)-/calmodulin-dependent protein kinase Ⅳ in Ca^(2+)-stimulated neuronal signaling and behavior

The activity of Ca2+/calmodulin-dependent protein kinase IV(Ca MKIV) is sensitive to activity-dependent changes in the level of intracellular Ca2+.Following neuronal stimulation,the activation of Ca MKIV may trigger synaptic modifications and transcriptional responses,both of which are involved in regulating cognitive and emotional behavior.Here,we used Ca MKIV knockout(KO) neurons and mice to examine the function of Ca MKIV in Ca2+-stimulated intracellular signaling and animal behavior,respectively.Following NMDA receptor activation or membrane depolarization,the up-regulation of CREB(c AMP responsive element binding protein) and its target gene Bdnf(brain-derived neurotrophic factor) was intact in cortical neurons obtained from Ca MKIV KO mice.Ca MKIV KO mice displayed severe impairment in contextual fear memory but normal locomotor activity and anxiety level in the contextual training chamber.Although Ca MKIV KO mice showed normal memory in the standard passive avoidance task,they were defective in learning the temporal dissociative passive avoidance task.As indicated by the light/dark test and marble-burying test data,Ca MKIV KO mice showed less anxiety and normal perseveration.In the voluntary wheel-running test,Ca MKIV KO mice showed normal running time and distance but higher maximal running speed.Our results demonstrate the function of Ca MKIV in regulating different forms of fear memory,anxiety,and certain aspect of motor function.

Inducible regulation of GDNF expression in human neural stem cells

Glial cell derived neurotrophic factor （GDNF） holds promises for treating neurodegenerative diseases such as Parkinson＇s dis- ease. Human neural stem cells （hNSCs） have proved to be a suitable cell delivery vehicle for the safe and efficient introduction of GDNF into the brain. In this study, we used hNSCs-infected with a lentivirus encoding GDNF and the hygromycin re- sistance gene as such vehicles. A modified tetracycline operator 7 （tetO7） was inserted into a region upstream of the EFI-α promoter to drive GDNF expression. After hygromycin selection, hNSCs were infected with a lentivirus encoding a KRAB-tetracycline repressor fusion protein （TTS）. TTS bound to tetO7 and suppressed the expression of GDNF in hNSCs. Upon administration of doxycycline （Dox） the TTS-tetO7 complex separated and the expression of GDNF resumed. The hNSCs infected with GDNF expressed the neural stem cell specific markers, nestin and sox2, and exhibited no significant change in proliferation rate. However, the rate of apoptosis in hNSCs expressing GDNF was lower compared with normal NSCs in response to actinomycin treatment. Furthermore, a higher percentage of Tuj-I positive cells were obtained from GDNF-producing NSCs under conditions that induced differentiation compared to control NSCs. The inducible expression of GDNF in hNSCs may provide a system for the controllable delivery of GDNF in patients with neurodegenerative diseases.