Effect of chronic olanzapine treatment on nerve growth factor and brain-derived neurotrophic factor in the rat brain.

Nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) are proteins involved in neuronal survival, neurite outgrowth and synapse formation. Recent observations suggest that treatment with typical and atypical antipsychotic drugs affect NGF and BDNF levels in the rat brain. The atypical antipsychotic olanzapine has a low incidence of side effects, such as extrapyramidal and anticholinergic symptoms. Since NGF and BDNF are involved in the regulation of cholinergic, dopaminergic and serotonergic neurons in the central nervous system (CNS) we hypothesized that chronic olanzapine treatment will influence the distribution of NGF and BDNF in the rat brain. To test this hypothesis we administered olanzapine for 29 days in the drinking water at the doses of 3 and 15 mg/kg body weight and measured the levels of NGF and BDNF in the brain of Wistar rats. Olanzapine increased NGF in the hippocampus, occipital cortex and hypothalamus. In contrast, olanzapine decreased BDNF in the hippocampus and frontal cortex. Although the significance of these findings is not clear, a heuristic hypothesis is that olanzapine's clinical effects and a favorable side effect profile are in part mediated by neurotrophins.     

The Signaling Pathway of Neurotrophic Factor Biosynthesis

There are various neurotrophic factors, such as nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF) and interleukin-6 (IL-6), which are essential for the promotion of neuronal survival (prevention of apoptosis), differentiation and regeneration in the central nervous system. Neurotrophic factors, neurotrophic factor-like substances and inducers of neurotrophic factor biosynthesis have enormous therapeutic potential for serious neuronal diseases such as Alzheimer's disease or traumatic, chemical and ischemic lesions in the brain. The clarification of the mechanism in neurotrophic factor biosynthesis is important in understanding the development of the drugs that stimulate neurotrophic factor production. In this review, we describe these mechanisms in the biosynthesis of NGF, BDNF, GDNF and IL-6, and also discuss the drugs that could possibly promote neurotrophic factor biosynthesis. (c) 2002 Prous Science. All rights reserved.     

Glia as targets for antidepressants: an involvement in glial cell line-derived neurotrophic factor]

Recently, clinical and animal studies have shown that neuronal and glial plasticity are important for the therapeutic action of antidepressants. Thus, it has been suggested that neurotrophic factors or growth factors, which are potent regulators for neuronal and glial plasticity, might be involved in the effect of antidepressants. Post-mortem studies provide evidence for glial reduction in different brain areas in mood disorders. Therefore, we focused on glial cell line-derived neurotrophic factor (GDNF) in mood disorders, because GDNF plays an important role in neurogenesis and high-ordered brain function, such as learning and memory. GDNF family ligands have shown promise of efficacy for neurodegenerative disorders such as Parkinson's disease, suggesting that GDNF family ligands exist in the closest position to clinical development for treatment of diseases of the central nervous system. We reported that total GDNF levels in whole blood in patients with mood disorders were significantly lower than those in healthy control subjects (Takebayashi et al, 2006), and antidepressants increased GDNF production through monoamine-independent activation of protein tyrosine kinase (PTK) and extracellular signal-regulated kinase (ERK) in glial cells (Hisaoka et al, 2007). Clarifying the monoamine-independent novel target of antidepressants in glia might contribute to the development of more efficient therapeutics for depression.     

阻塞性睡眠呼吸暂停低通气综合征老年患者神经营养因子水平与认知功能的相关性

目的 探讨阻塞性睡眠呼吸暂停低通气综合征(OSAHS)患者血清神经营养因子水平的变化及其与认知功能间的相关性。方法 按顺序纳入该院2013年5月至2014年9月收治的患者77例,参照呼吸暂停低通气指数(AHI)标准分为轻度OSAHS组25例、中度OSAHS组25例和重度OSAHS组27例;同时选择25例体检者作为健康对照组;分别进行多导睡眠图(PSG)监测;采用蒙特利尔认知评估量表(MoCA)和简易智能状态量表(MMSE)对各组的认知功能进行评价;并检测血清神经生长因子(NGF),脑源性神经营养因子(BDNF),胶质细胞源性神经营养因子(GDNF)和睫状神经营养因子(CNTF)水平。分析以上参数间的相关性。结果与对照组比较,轻、中和重度OSAHS组患者的AHI、氧减指数(ODI)、呼吸相关微觉醒指数(RI)和脉氧饱和度低于90％的时间占总睡眠时间的百分比(TS90％)均明显升高(P＜0.01),且重度组较轻和中度组升高更明显(P＜0.01);而重度组患者的最低脉氧饱和度(LSaO₂)和平均脉氧饱和度(MSaO₂)较对照组明显降低(P＜0.01);与对照组比较,重度OSAHS组患者的MoCA、MMSE评分显著降低(P＜0.01);与轻、中度OSAHS组相比,重度OSAHS组MoCA评分显著降低(P＜0.01)。与对照组比较,轻、中和重度OSAHS组患者血清神经营养因子水平均减少;而重度OSAHS组患者血清营养因子较对照组、轻和中度OSAHS组患者明显减少,比较差异有统计学意义(P＜0.01)。血清营养因子水平与睡眠呼吸记录指标AHI、ODI、RI 和TS90％呈负相关,而与最低SaO₂和平均SaO₂呈正相关。血清营养因子水平与认知功能指标MoCA 和MMSE均呈正相关。结论 血清神经营养因子水平是反映OSAHS患者的重要指标,且与其认知功能障碍密切相关。     

骨髓基质细胞对脑创伤大鼠神经营养因子表达水平的影响

目的:研究骨髓基质细胞(BMSCs)治疗脑创伤大鼠后内源性的神经生长因子(NGF)和脑源性神经营养因子(BDNF)的影响。方法:采用大鼠骨髓中提取出来的骨髓基质细胞,进行体外扩增后,静脉移植于大鼠脑创伤模型中,在治疗后1、3、5、7、14d,ELISA法检测损伤半球NGF和BDNF的浓度,并与对照组对比,进行统计学分析。免疫组化法检测骨髓基质细胞在损伤脑组织中的表达。结果:骨髓基质细胞经股静脉移植后可在损伤的脑组织中表达。治疗组NGF和BDNF的表达于伤后1d至7d逐渐增加,于第7天达到高峰,至第14天降至较低水平。结论:骨髓基质细胞经股静脉移植后可在损伤的脑组织中表达。移植后的骨髓基质细胞可增加损伤脑组织中的NGF和BDNF的表达,与时间有相关性。体外扩增的骨髓基质细胞对于创伤性脑损伤具有治疗作用。     

Brain-derived neurotrophic factor and antidepressant activity

Brain-derived neurotrophic factor (BDNF) is a member of the structurally and functionally homologous neurotrophin family. It is the most widely distributed trophic factor in the brain, and participates in neuronal growth, maintenance, and use-dependent plasticity mechanisms such as long-term potentiation and learning. There are several lines of evidence supporting a role for BDNF in the treatment of depression. This paper reviews the neurotrophin hypothesis of antidepressant action, and examines our current understanding of activity-dependent mechanisms of BDNF expression and function in limbic regions of the brain. Our discussion starts with the original observations of monoaminergic neurotransmitter dysfunction that served as the basis for early antidepressant drug development, and outlines evidence for neurodegeneration and functional deficits existing with chronic stress and depression. We continue with evidence that enhancement in neurotrophic support and associated augmentation in synaptic plasticity and function may form the basis for antidepressant efficacy, and serve as a current and future focus in the quest for more rapid-acting and effective medication treatments. Finally, we follow the current search for the intracellular mechanisms of antidepressant interventions that may bring the monoaminergic and neurotrophic hypotheses together, and help us to more fully understand the roles of both neurotransmitter and growth factor. Principal challenges to the neurotrophin hypothesis, and inconsistencies between clinical and preclinical research results, are also pointed out, as these also guide future experiments that will refine our understanding of treatment mechanisms.     

临床孤立综合征患者血清和脑脊液中脑源性与胶质细胞源性神经营养因子水平及其神经保护作用研究

目的 探讨多发性硬化（MS）的早期表现--临床孤立综合征（CIS）患者血清及脑脊液中脑源性神经营养因子（BDNF）、胶质细胞源性神经营养因子（GDNF）水平及其神经保护作用.方法 对27例CIS患者及21例对照者进行研究,CIS患者发作期进行扩展残疾状态量表（EDSS）评分、寡克隆带测定及MRI检查,液相芯片分析技术检测血清及脑脊液BDNF、GDNF浓度.结果 CIS患者发作期血清及脑脊液BDNF[分别为（5.981±0.995）和（0.178±0.008）μg/L]、GDNF浓度[分别为（0.039±0.007）和（0.082±0.011）μg/L]与对照组[血清：（4.374±0.501）、（0.042±0.007）μg/L;脑脊液：（0.152±0.011）、（0.065±0.013）μg/L]比较差异均无统计学意义（均P＞0.05）;脑脊液BDNF与GDNF浓度呈正相关（r=0.777,P=0.000）,血清BDNF与GDNF浓度无相关性（r=-0.375,P=0.126）.血清及脑脊液BDNF、GDNF浓度与EDSS评分、血脑屏障指数、Delpech指数、Tourtellotte合成率及脑萎缩无明显相关性（P＞0.05）.结论 CIS患者体内BDNF与GDNF水平相关,二者可能具有协同的神经保护作用.BDNF及GDNF与CIS患者血脑屏障破坏及中枢神经系统内IgG合成无关,与神经功能残疾及脑萎缩的关系仍需研究.     

Role of neurotrophic factors in depression

Major depression is associated with reduced volumes in the hippocampus and prefrontal cortex, whereas antidepressant treatments promote several forms of neuronal plasticity, including neurogenesis, synaptogenesis and neuronal maturation, in the hippocampus. Several neurotrophic factors are associated with depression or antidepressant action. Stress suppresses brain-derived neurotrophic factor (BDNF) synthesis in the hippocampus, at least partially through a sustained modification of chromatin structure. Essentially all antidepressant treatments increase BDNF synthesis and signaling in the hippocampus and prefrontal cortex. This signaling is required for the behavioral effects of antidepressant drugs in rodents, and increased BDNF levels in the hippocampus mimic the behavioral effects of antidepressants. However, injection of BDNF into the mesolimbic dopamine pathway produces an opposing depression-like response. One hypothesis emerging from these data proposes that mood disorders reflect failed function of critical neuronal networks, whereas a gradual network recovery through activity-dependent neuronal plasticity induces the antidepressant effect. Neurotrophic factors themselves do not control mood, but they act as necessary tools in the activity-dependent modulation of networks, the physiological function of which determines how a plastic change influences mood.     

Brain-derived neurotrophic factor as a drug target for CNS disorders

Brain-derived neurotrophic factor (BDNF) belongs to the neurotrophin family of trophic factors. BDNF is widely and abundantly expressed in the CNS and is available to some peripheral nervous system neurons that uptake the neurotrophin produced by peripheral tissues. BDNF promotes survival and differentiation of certain neuronal populations during development. In adulthood, BDNF can modulate neuronal synaptic strength and has been implicated in hippocampal mechanisms of learning and memory and spinal mechanisms for pain. Several CNS disorders are associated with a decrease in trophic support. As BDNF and its high affinity receptor are abundant throughout the whole CNS, and BDNF is a potent neuroprotective agent, this trophic factor is a good candidate for therapeutic treatment of some of CNS disorders. This review aims to correlate the features of some CNS disorders (Parkinson's disease, Alzheimer's disease, depression, epilepsy and chronic pain) to changes in BDNF expression in the brain. The cellular and molecular mechanism by which BDNF might be a therapeutic strategy are critically examined.     

Stress-mediated decreases in brain-derived neurotrophic factor as potential confounding factor for acute tryptophan depletion-induced neurochemical effects

Acute tryptophan depletion (ATD) is extensively used to investigate the implication of serotonin (5-hydroxytryptamine; 5-HT) in the onset and treatment of depression and cognitive disorders. Brain-derived neurotrophic factor (BDNF) is strongly linked to the 5-HT system and plays an essential role in mood and memory processes. The present study investigated the effects of ATD upon BDNF in serum, hippocampus and prefrontal cortex in the rat to further explore the underlying mechanism of ATD.ATD significantly decreased peripheral tryptophan (TRP) levels and moderately interrupted 5-HT metabolism 4 h after administration of the nutritional mixture. Although no direct effects of ATD upon serum or brain BDNF concentrations were found, a stress-mediated, decrease in BDNF was observed in the prefrontal cortex. Moreover, brain TRP levels correlated positively with BDNF in both the prefrontal cortex and hippocampus. Thus, BDNF-mediated mechanisms due to ATD and/or its application stress might underlie ATD-induced neurochemical and behavioural alterations.     

Hepatocyte growth factor,vascular endothelial growth factor,glial cell-derived neurotrophic factor and nerve growth factor are differentially affected by early chronic ethanol or red wine intake

Ethanol intake during pregnancy and lactation induces severe changes in brain and liver throughout mechanisms involving growth factors. These are signaling molecules regulating survival, differentiation, maintenance and connectivity of brain and liver cells. Ethanol is an element of red wine which contains also compounds with antioxidant properties. Aim of the study was to investigate differences in hepatocyte growth factor (HGF), vascular endothelial growth factor (VEGF), glial cell-derived neurotrophic factor (GDNF) and nerve growth factor (NGF) in brain areas and liver by ELISA of 1-month-old male mice exposed perinatally to ethanol at 11 vol.% or to red wine at same ethanol concentration. Ethanol was administered before and during pregnancy up to pups’ weaning. Ethanol per se elevated HGF in liver and cortex, potentiatied liver VEGF, reduced GDNF in the liver and decreased NGF content in hippocampus and cortex in the offspring. We did not find changes in HGF or NGF due to red wine exposure. However, we revealed elevation in VEGF levels in liver and reduced GDNF in the cortex of animals exposed to red wine but the VEGF liver increase was more marked in animals exposed to ethanol only compared to the red wine group. In conclusion the present findings in the mouse show differences in ethanol-induced toxicity when ethanol is administered alone or in red wine that may be related to compounds with antioxidant properties present in the red wine.     

Dissociation of antidepressant-like activity of escitalopram and nortriptyline on behaviour and hippocampal BDNF expression in female rats

A major hypothesis of depression postulates that a dysregulation of the neurotrophin systems is directly involved in the pathophysiology of depression, and that restoration of such deficits may underlie the therapeutic efficacy of antidepressant treatment. One key finding supporting this hypothesis is upregulation of brain derived neurotrophic factor (BDNF) in the hippocampus after antidepressant treatment. Here, we further test the hypothesis of BDNF involvement in antidepressant action in a genetic rat model of depression after chronic oral treatment with escitalopram, nortriptyline or placebo. Active treatments had significant behavioural antidepressant-like actions in female rats of the Flinders Sensitive Line (FSL) and non-selected Sprague Dawley (SD) rats, while Flinders Resistant Line (FRL) rats were unaffected. Escitalopram, but not nortriptyline, markedly reduced BDNF mRNA levels in the dentate gyrus of FSL rats. The BDNF downregulation was common to the four major promoters of the gene. Treatments did not affect BDNF expression in FRL or SD strains. We conclude that the antidepressant effects of escitalopram and nortriptyline, two common drugs with different pharmacological profiles, appear to be unrelated to the regulation of hippocampal BDNF expression in female rats. These results indicate that the tropic hypothesis of depression has limitations and emphasize the need for validated disease models of depression to assess potential treatment targets.     

Brain-derived neurotrophic factor as a drug target for CNS disorders

Brain-derived neurotrophic factor (BDNF) belongs to the neurotrophin family of trophic factors. BDNF is widely and abundantly expressed in the CNS and is available to some peripheral nervous system neurons that uptake the neurotrophin produced by peripheral tissues. BDNF promotes survival and differentiation of certain neuronal populations during development. In adulthood, BDNF can modulate neuronal synaptic strength and has been implicated in hippocampal mechanisms of learning and memory and spinal mechanisms for pain. Several CNS disorders are associated with a decrease in trophic support. As BDNF and its high affinity receptor are abundant throughout the whole CNS, and BDNF is a potent neuroprotective agent, this trophic factor is a good candidate for therapeutic treatment of some of CNS disorders. This review aims to correlate the features of some CNS disorders (Parkinson’s disease, Alzheimer’s disease, depression, epilepsy and chronic pain) to changes in BDNF expression in the brain. The cellular and molecular mechanism by which BDNF might be a therapeutic strategy are critically examined.     

脑源性神经营养因子与脑卒中后疼痛和抑郁的关系

脑源性神经营养因子（BDNF）是成人脑内含量最丰富的神经营养因子,具有显著的脑损伤修复能力。最近的多项研究表明,BNDF在脑卒中后的多种并发症的发生发展中起到了重要的作用,有希望成为新的卒中治疗方法的晚期靶点,但它的作用机制尚不明确。本文就BDNF的生物学特性、在卒中后并发症的作用机制以及最新的研究进展进行综述,从而为...     

Reduced serum concentrations of nerve growth factor, but not brain-derived neurotrophic factor, in chronic cannabis abusers

Chronic cannabis use produces effects within the central nervous system (CNS) which include deficits in learning and attention tasks and decreased brain volume. Neurotrophins, in particular nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF), are proteins that serve as survival factors for CNS neurons. Deficits in the production and utilization of these proteins can lead to CNS dysfunctions including those associated with cannabis abuse.In this study we measured by enzyme-linked immunosorbent assay (ELISA) the NGF and BDNF serum levels in two groups of subjects: cannabis-dependent patients and healthy subjects. We found that NGF serum levels were significantly reduced in cannabis abusers as compared to healthy subjects.These findings indicate that NGF may have a role in the central action of cannabis and potentially in the neurotoxicity induced by this drug. These data also suggest that chronic cannabis consumption may be a risk factor for developing psychosis among drug users.     

Changed concentrations of tachykinins and neuropeptide Y in brain of a rat model of depression: lithium treatment normalizes tachykinins.

Lithium's therapeutic mechanism of action is unknown. In lithium-treated normal rats, increased striatal concentrations of neurokinin A (NKA)-like immunoreactivity (LI), substance P (SP-LI) and neuropeptide Y (NPY-LI) have been reported. To investigate whether these effects might be of therapeutic relevance, Flinders Sensitive Line rats (FSL), an animal model of depression, and control Flinders Resistant Line (FRL) rats were during a 6-week period fed chow to which either lithium or vehicle was admixed. Following sacrifice, the peptides were extracted from dissected brain regions and measured by radioimmunoassay. NKA-LI and SP-LI were markedly decreased in striatum and increased in frontal cortex in FSL compared to control FRL animals. Lithium treatment abolished these differences. Basal concentrations of NPY-LI were decreased in hippocampus of FSL rats, but unaffected by lithium. The present study suggests that changed tachykinins and NPY may underlie the characterized depressive-like phenotype of the FSL rats. It is hypothesized that altering tachykinin peptidergic neurotransmission in striatum and frontal cortex constitutes a mechanism of action of lithium and that such a mechanism might be of therapeutic relevance.     

Studies in animal models and humans suggesting a role of nerve growth factor in schizophrenia-like disorders

Neurotrophic factors, such as nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF), are known to play a crucial role in growth, differentiation and function in a variety of brain neurons during development and in adult life. We have recently shown that environmental changes, aggressive behavior and anxiety-like responses alter both circulating and brain basal NGF levels. In the present review, we present data obtained using animal models which suggest that neurotrophic factors, particularly NGF and BDNF, might be implicated in mechanism(s) leading to a condition associated with schizophrenic-like behaviors. The hypothesis that neurotrophins of the NGF family can be implicated in some maldevelopmental aspects of schizophrenia is supported by findings indicating that the constitutive levels of NGF and BDNF are affected in schizophrenic patients.     

The influence of orally administered docosahexaenoic acid on monoamine neurotransmitter,nerve growth factor,and brain-derived neurotrophic factor in aged mice

In this study we attempt to investigate the new role of docosahexaenoic acid (DHA) supplementation on cognitive ability in aged mice. Kunming-line mice were treated with DHA (200, 400?mg/kg body weight/day) for 30 successive days. The cognitive ability of mice was assessed by learning and memory behavioral test; the levels of DHA were assessed by capillary gas chromatography; the levels of dopamine (DA), norepinephrine (NE), and 5-hydroxytryptamine (5-HT) were assessed by high-performance liquid chromatography; the levels of brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) proteins were assessed by the enzyme-linked immunosorbent assay method. The results showed the cognitive ability of mice were significantly different between the DHA-treated groups and the aged group, and orally administered DHA can increase the levels of DA, NE and 5-HT, the content of BDNF and NGF proteins in hippocampus, frontal cortex and striatum tissues. In addition, aged-related changes in phospholipid DHA content were seen. Decreases in DHA were mostly corrected by DHA supplementation. These novel data suggest that DHA supplementation can improve the cognitive dysfunction due to aging by increasing the levels of BDNF and NGF protein and the levels of DA, NE, 5-HT to some extent. We speculate that the mechanism of DHA on cognitive ability may have a beneficial effect on signaling networks through modulation of monoamine neurotransmitters and neurotrophic factors in brain aging.     

Chronic heroin and cocaine abuse is associated with decreased serum concentrations of the nerve growth factor and brain-derived neurotrophic factor

Chronic cocaine and heroin users display a variety of central nervous system (CNS) dysfunctions including impaired attention, learning, memory, reaction time, cognitive flexibility, impulse control and selective processing. These findings suggest that these drugs may alter normal brain functions and possibly cause neurotoxicity. Neurotrophins are a class of proteins that serve as survival factors for CNS neurons. In particular, nerve growth factor (NGF) plays an important role in the survival and function of cholinergic neurons while brain-derived neurotrophic factor (BDNF) is involved in synaptic plasticity and in the maintenance of midbrain dopaminergic and cholinergic neurons. In the present study, we measured by enzyme-linked immunosorbent assay (ELISA) the NGF and BDNF levels in serum of three groups of subjects: heroin-dependent patients, cocaine-dependent patients and healthy volunteers. Our goal was to identify possible change in serum neurotrophins in heroin and cocaine users. BDNF was decreased in heroin users whereas NGF was decreased in both heroin and cocaine users. These findings indicate that NGF and BDNF may play a role in the neurotoxicity and addiction induced by these drugs. In view of the neurotrophin hypothesis of schizophrenia the data also suggest that reduced level of neurotrophins may increase the risk of developing psychosis in drug users.