High vs low anxiety-related behavior rats: an animal model of extremes in trait anxiety

In addition to their robust difference in trait anxiety, as illustrated by a variety of behavioral tests, HAB and LAB rats differ in their stress coping strategies, the former being more susceptible and vulnerable to stressor exposure and preferring more passive strategies. HAB rats of either gender show signs of a hyper-reactive hypothalamic-pituitary-adrenocortical (HPA) axis, thus resembling psychiatric patients. As shown by in situ hybridization and microdialysis in freely behaving animals, both the expression and release of vasopressin in the hypothalamic paraventricular nucleus are higher in HAB than in LAB rats, thus contributing to the HPA axis hyperdrive. Accordingly, in HAB animals, administration of a V1 receptor antagonist normalized the pathological outcome of the dexamethasone/corticotropin-releasing hormone test and triggered behavioral changes toward reduced anxiety and active stress coping. Pharmacological validation has revealed signs of depressive-like behavior, as HAB but not LAB rats have shown more active stress coping behavior and a normalized HPA axis after treatment with paroxetine. Of interest, this antidepressant reduced the hypothalamic overexpression of vasopressin; this novel mechanism of action is likely to contribute to paroxetine effects on both behavioral and neuroendocrine parameters. Cross-mating and cross-fostering paradigms showed that the divergent emotionality in HAB vs. LAB rats is determined genetically, rather than postnatally through maternal behavior. As the behavioral and neuroendocrine phenotyping pointed to the vasopressin gene as a candidate gene critically involved in anxiety, preliminary genetic approaches have been focused on this gene, revealing single nucleotide polymorphisms (SNPs) in the promotor area of the vasopressin gene in HAB, but not LAB rats. HAB/LAB rats are thus proving to be a unique animal model to identify and characterize neurobiological, neuroendocrine, and genetic correlates of trait anxiety, and perhaps depression, in humans.     

An enriched environment restores normal behavior while providing cytoskeletal restoration and synaptic changes in the hippocampus of rats exposed to an experimental model of depression

The exposure of rats to an enriched environment (EE) has several effects in common with the administration of antidepressants. However, there is still little information about the molecular underpinnings of these effects on rats subjected to experimental models of depression. The aim of this research was to evaluate the effects of EE on rats exposed to the learned helplessness paradigm (LH), a well-known model of the disease. We found that a 21 day exposure to EE reverts helplessness behavior to normal in LH animals. Inmunohistochemical labeling showed that this effect was accompanied by normalization of two structural proteins of hippocampal neurons to control values: the light neurofilament subunit (NFL) and the postsynaptic density 95 (PSD-95) protein, which were decreased in LH animals housed in standard cages. The decrease in the presynaptic protein synaptophysin (SYN) observed in LH animals remained unchanged after exposure to EE. There was no increase in neurogenesis as measured by quantification of double-labeled cells with 5-bromo-2′-deoxyuridine (BrdU) and the neuronal marker β-tubulin class III. These results show that EE may have behavioral and synaptic effects on animals exposed to an experimental model of depression, and that such actions seem to be independent from neurogenesis.     

Dysfunctional nurturing behavior in rat dams with limited access to nesting material: a clinically relevant model for early-life stress

BACKGROUND: Early-life emotional stress may be associated with affective and cognitive disorders later in life, yet satisfactory animal models for studying the underlying mechanisms are limited. Because maternal presence and behavior critically influence molecular and behavioral stress responses in offspring, we sought to create a model of dysfunctional, fragmented maternal nurturing behavior that would, in turn, provoke chronic early-life stress in the offspring. METHODS: Sprague-Dawley rat dams' nursing and nurturing behaviors were altered by limiting their ability to create satisfactory nests during postpartum days 2-9. Maternal behavior was observed throughout the diurnal cycle, and the frequency and duration of nurturing behaviors were scored. In addition, potential stress and anxiety of the dams were assessed using behavioral, molecular and hormonal measures. RESULTS: Both the quantity and the quality of dams' care of their pups were profoundly influenced by restriction of nesting materials in their cages: licking/grooming activities decreased and the frequency of leaving the pups increased, resulting in fragmented interactions between the dams and pups. The abnormal activity patterns of the dams were accompanied by increased anxiety-like behavior in the open field, but not in the elevated plus maze tests. Additionally, dams' plasma corticosterone levels and adrenal weights were augmented, suggesting chronic stress of these dams. By the end of the limited-nesting, stress-inducing period, hypothalamic corticotropin releasing hormone (CRH) mRNA expression was reduced in the limited-nesting dams, while arginine-vasopressin (AVP) mRNA levels were not significantly affected. CONCLUSION: Limiting dams' ability to construct a nest for their pups leads to an abnormal repertoire of nurturing behaviors, possibly as a result of chronic stress and mild anxiety of the dams. Because the fragmented and aberrant maternal behavior provoked chronic stress in the pups, the limited-nesting paradigm provides a useful tool for studying the mechanisms and consequences of such early-life stress experience in the offspring.     

Timing of fetal exposure to stress hormones: effects on newborn physical and neuromuscular maturation

The purpose of the study was to determine the specific periods during pregnancy in which human fetal exposure to stress hormones affects newborn physical and neuromuscular maturation. Blood was collected from 158 women at 15, 19, 25, and 31 weeks' gestation. Levels of placental corticotropin-releasing hormone (CRH) and maternal cortisol were determined from plasma. Newborns were evaluated with the New Ballard Maturation Score. Results indicated that increases in maternal cortisol at 15, 19, and 25 weeks and increases in placental CRH at 31 weeks were significantly associated with decreases in infant maturation among males (even after controlling for length of gestation). Results also suggested that increases in maternal cortisol at 31 weeks were associated with increases in infant maturation among females, although these results were not significant after controlling for length of gestation. Findings suggest that stress hormones have effects on human fetal neurodevelopment that are independent of birth outcome.     

外源性硫化氢在改善慢性应激引起大鼠抑郁作用的研究

目的:探讨外源性硫化氢供体NaH S对慢性应激致大鼠抑郁模型的影响,为抑郁症的防治提供新思路。方法:SD大鼠按随机数字表法分为4组:正常对照组、模型组、模型+NaH S组、模型+NS组,每组6只。模型+NaH S组和模型+NS组大鼠在建模前分别给予NaH S 10 mg/kg或等量生理盐水腹腔注射。记录各组大鼠的体重、食量、饮水量、糖水偏好率、肾上腺指数及行为学指标,并收集大鼠海马组织,采用Real-Time PCR和Western Blot分别检测海马组织糖皮质激素受体和盐皮质激素受体基因mRNA及蛋白表达量。结果:模型组大鼠的体重、食量、饮水量、糖水偏好率、水平运动格数及垂直竖立次数较正常对照组均明显降低(P0.05),而肾上腺指数在模型组显著高于正常对照组(P0.05);NaH S处理的模型组大鼠体重、食量、饮水量、糖水偏好率、水平运动格数及垂直竖立次数均明显增加,且肾上腺指数显著降低,与模型组相比差异有统计学意义(均P0.05)。Real-Time PCR和Western Blot结果显示:海马组织中糖皮质激素受体和盐皮质激素受体基因mRNA及蛋白表达量在模型组均明显低于正常对照组,模型+NaH S组均显著高于模型组,两组相比差异有统计学意义(均P0.05)。结论:慢性应激可引起大鼠抑郁表现,而外源性硫化氢供体NaH S能够显著上调糖皮质激素受体和盐皮质激素受体表达水平,从而改善慢性应激所致的大鼠抑郁。     

Acupuncture inhibits NLRP3 inflammasome activation in the prefrontal cortex of a chronic stress rat model of depression

The Nod-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome-driven inflammatory response plays a key role in the pathophysiology of depression. Mounting evidence suggests that acupuncture is an effective treatment for depression. In this study, we investigated the effects of acupuncture treatment at the acupoints Baihui (GV20) and Yintang (GV29) on NLRP3 inflammasome in the prefrontal cortex (PFC) of an animal model of depression. Rats that underwent chronic unpredictable mild stress (CUMS) for 6 weeks showed depressive-like behaviors, which were confirmed by sucrose preference and locomotor activity in the open field test. The protein levels of NLRP3, apoptotic speck-containing protein with a card (ASC), and cysteinyl aspartate specific proteinase-1 (Caspase-1) in the PFC were detected by Western blot analysis. The mRNA and protein expressions of interleukin-1β (IL-1β) and interleukin-18 (IL-18) in the PFC were measured by the real-time polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA), respectively. Our results showed that the depressive-like behaviors in stressed rats were reversed by acupuncture treatment. Compared with control rats, the protein expression of NLRP3, ASC, and Caspase-1 and the mRNA and protein expressions of IL-1β and IL-18 in the PFC were markedly increased in CUMS rats. Acupuncture treatment significantly decreased the levels of NLRP3 inflammasome components and inflammatory cytokines in the PFC. Acupuncture treatment also reduced the number of TUNEL-positive cells in the PFC. These results suggested that acupuncture has antidepressant-like effects, and its mechanism appears to be involved in the inhibition of NLRP3 inflammasome activation and apoptosis in the PFC.     

慢性应激抑郁状态对大鼠海马神经元再生的影响

目的:探讨慢性应激性刺激引起的抑郁状态对大鼠海马神经元再生的影响。方法:建立大鼠慢性应激性抑郁症模型,通过开场实验和蔗糖饮水实验观察大鼠行为学变化;取大鼠脑冰冻切片行Doublecortin(DCX)免疫荧光检测海马新生神经元。结果:慢性应激抑郁模型大鼠开场实验水平运动得分和垂直运动得分降低,蔗糖偏嗜度降低,且体重明显减轻;免疫荧光结果显示慢性应激抑郁模型大鼠海马齿状回颗粒下层(subgranularzone SGZ)DCX阳性细胞减少。结论:慢性应激性刺激引起的抑郁状态下大鼠海马神经元再生能力减弱,提示海马神经元再生的损害可能参与了抑郁症的病理过程。     

Comparing outcomes in chronic depression following inpatient psychotherapy for patients continuing versus discontinuing antidepressant medication

Research indicates that combination of psychotherapy and antidepressant medication (ADM) provides cumulative effects and thus outperforms monotherapy in treating chronic depression. In this quasi-experimental study, we explored symptom change for patients with chronic depression treated with ADM when presenting for a 12-week psychotherapeutic inpatient treatment programme. We compared outcomes through treatment and follow-up of patients who continued medication with those who discontinued. We also tested possible moderator effects of initial depression severity on change between the groups. Based on prior research, we hypothesized that combination treatment would yield better results (i.e., more reduction in depression). Patients (N = 112) were referred from general practitioners or local secondary health care. Outcome was measured by Beck Depression Inventory-II (BDI-II), and comparisons were carried out using multilevel modelling. Although 35 patients discontinued ADM during treatment, 77 continued. Both continuers and discontinuers had a significant treatment effect that was maintained at 1-year follow-up. There was no difference in outcome between continuers and discontinuers of ADM. Patients with severe depression had significantly more symptom improvement than patients with moderate depression, but depression severity did not affect outcomes across continuers and discontinuers of ADM differently. The results could indicate that patients had developed resistance and/or tolerance to the prophylactic effects of medication and that ADM did not contribute to the reduction of depressive symptoms. The findings may also indicate that psychotherapy alone in some instances can be a viable alternative to continued combined treatment. Clinicians should carefully assess benefits of patients' ongoing use of antidepressant medication when entering psychotherapy.     

GSK650394对慢性应激抑郁症模型大鼠行为及海马神经营养的调节作用

目的探讨血清和糖皮质激素调节蛋白激酶1(SGK1)抑制剂GSK650394对抑郁症模型大鼠抑郁样行为及海马神经营养的调节作用。方法将SD大鼠随机分为对照组、抑郁模型(慢性温和不可预见性应激加孤养)组、GSK650394(2.8 g/L,按1 mL/kg腹腔注射)干预组;采用强迫游泳、糖水消耗、Morris水迷宫实验观察模型动物的情绪行为变化;用ELISA检测大鼠海马血浆和血清中皮质酮(CORT)、5-羟色胺(5-HT)、去甲肾上腺素(NE)含量;用Western blot检测海马中脑源性神经营养因子(BDNF)、神经营养素3(NT-3)、神经生长因子(NGF)的表达。结果与对照组比较,模型组大鼠蔗糖水偏食度显著降低、游泳不动时间增加(P<0.01)、逃避潜伏期(EL)、目标象限的潜伏时间(Lat.T)均显著延长(P<0.05或P<0.01);血浆CORT显著升高(P<0.01)、血清5-HT、NE和海马NT-3、BDNF、NGF表达显著降低(P<0.05或P<0.01)。与模型组比较,GSK650394可显著增加蔗糖水偏食度、降低游泳不动时间(P&l...     

Role of the peripheral adrenergic component in effect of antidepressant on experimental behavioral depression in cats

Institute of Pharmacology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. V. Val'dman,) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 110, No. 12, pp. 620–623, December, 1990.     

Enhanced fear recall and emotional arousal in rats recovering from chronic variable stress

Emergence of posttraumatic-like behaviors following chronic trauma is of interest given the rising prevalence of combat-related posttraumatic stress disorder (PTSD). Stress associated with combat usually involves chronic traumatization, composed of multiple, single episode events occurring in an unpredictable fashion. In this study, we investigated whether rats recovering from repeated trauma in the form of chronic variable stress (CVS) express posttraumatic stress-like behaviors and dysregulated neuroendocrine responses. Cohorts of Long-Evans rats underwent a 7 day CVS paradigm followed by behavioral and neuroendocrine testing during early (16 h post CVS) and delayed (7 day) recovery time points. A fear conditioning-extinction-reminder shock paradigm revealed that CVS induces exaggerated fear recall to reminder shock, suggestive of potentiated fear memory. Rats with CVS experience also expressed a delayed expression of fearful arousal under aversive context, however, social anxiety was not affected during post-CVS recovery. Persistent sensitization of the hypothalamic-pituitary-adrenocorticotropic response to a novel acute stressor was observed in CVS exposed rats. Collectively, our data are consistent with the constellation of symptoms associated with posttraumatic stress syndrome, such as re-experiencing, and arousal to fearful contexts. The CVS-recovery paradigm may be useful to simulate trauma outcomes following chronic traumatization that is often associated with repeated combat stress.     

慢性社交挫败小鼠抑郁模型的代谢组分析

目的:通过代谢组学检测和分析,比较抑郁小鼠和对照小鼠前额叶皮质代谢物质的差异,探索脑代谢物与抑郁症之间的相互关系。方法:建立小鼠慢性社交挫败应激(CSDS)模型,并通过一系列行为学实验验证该动物模型。采用超高效液相四级杆飞行时间串联质谱非靶向代谢组学的分析技术检测具有抑郁表型的小鼠与对照组小鼠前额叶皮质脑区的代谢物质。并通过主成分分析(PCA)、偏最小二乘法判别分析(PLS-DA)及正交偏最小二乘法判别分析(OPLS-DA)等统计学方法来筛选并鉴定具有明显差异的代谢物质。结果:与正常组相比,模型组小鼠出现明显的抑郁样症状。在脑代谢物方面,与正常组相比,模型组前额叶皮质中有26种代谢物的含量发生了显著改变,其中11种代谢产物含量增高,15种代谢产物降低。通路分析结果中特别值得注意的有两个代谢物。其一是3-磷酸甘油乙醇胺,它是抑郁症相关的内源性大麻素系统中的成分之一,其含量增高。其二是色氨酸,它是抑郁症相关的5-HT合成相关代谢通路上的成分之一,其含量降低。结论:慢性抑郁症小鼠模型前额叶皮质的脑代谢产物发生了改变,这些改变有望作为一种代谢指标,以帮助诊断抑郁症和研发针对性的治疗方法。     

Sympatho-adrenal hyperreactivity to footshock stress but not to cold exposure in spontaneously hypertensive rats

No significant differences in plasma levels of catecholamines were found in blood obtained via an indwelling tail artery catheter from awake, undisturbed spontaneously hypertensive (SHR) and normotensive Wistar-Kyoto (WKY) or NIH Sprague-Dawley rats. Although the blood pressures of SHR rats increased between 4 and 10 months of age, there were no changes in basal plasma catecholamine levels. Exposure to cold for 20 or 240 min resulted in significant increments in plasma catecholamine levels which were similar in SHR and WKY rats. In contrast, exposure to 5 min of inescapable footshock (2.5 mA, 0.4 sec duration, every 5 sec) produced striking increments in plasma catecholamines that were greater in SHR rats than in normotensive WKY or NIH Sprague-Dawley rats. SHR rats also exhibited greater levels of plasma corticosterone than WKY rats at 15 min after termination of footshock. Our results demonstrate that SHR rats are hyperadrenergic in their responses to some but not all forms of stressful stimulation.     

慢性强迫游泳应激抑郁模型大鼠海马钙离子浓度和c-fos表达的改变

目的:观察慢性强迫游泳应激模型大鼠海马区[Ca2+]i和c-fos/Fos的变化,探讨慢性应激抑郁症与海马相关的发病机制。方法:选用雄性成年Wistar大鼠80只,将大鼠随机分为正常对照组(n=19)、急性对照组(n=12)和模型组(n=49),建立慢性强迫游泳应激抑郁模型,通过糖水偏好实验和开场实验对大鼠进行行为学测试。采用荧光分光光度法测定海马内[Ca2+]i浓度,免疫印迹技术和逆转录-聚合酶链式反应检测Fos和c-fos的表达变化。结果:与正常对照组大鼠相比较:(1)模型组大鼠相对糖水消耗量、糖水偏好百分比、直立次数和体重增长率均降低(P0.01,P0.05);(2)模型组大鼠各个时间点海马神经元[Ca2+]i增高(P0.01);(3)模型组大鼠海马Fos在应激后(0.5,1,2,4h)表达增强(P0.01),c-fosmRNA在应激后(0.5,1,2,4h)转录增强(P0.01)。与急性对照组相比较,模型组Fos蛋白表达高峰提前,表达量降低(P0.05)。结论:海马[Ca2']i及c-fos/Fos的表达变化,可能参与了抑郁症的发病过程。     

慢性轻度不可预见性应激对大鼠海马内甘丙肽表达的影响

目的:观察慢性轻度不可预见性应激(chronic unpredictable mild stress,CUMS)对大鼠海马甘丙肽(ga-lanin,Gal)蛋白及mRNA表达的影响,探讨Gal在大鼠实验性抑郁症发病过程中的作用机制。方法:将20只健康雄性SD大鼠,随机分为正常组和模型组,每组10只。孤养结合CUMS 21 d建造抑郁症模型,应用旷场试验和糖水偏好试验检测大鼠行为学变化,使用免疫荧光组织化学方法和逆转录多聚酶链反应(RT-PCR)法测定Gal及Gal mRNA的表达。结果:造模后模型组大鼠运动总路程、中央路程、周边路程及糖水摄入量均较正常组偏低(P<0.05);模型组与正常组相比,海马内Gal及Gal mRNA的表达同样降低(P<0.05)。结论:慢性轻度不可预见性应激可使大鼠海马内Gal及Gal mRNA的表达量下降,推测Gal在抑郁发病过程中可能起到神经保护作用。     

Imbalance of immunohistochemically characterized interneuron populations in the adolescent and adult rodent medial prefrontal cortex after repeated exposure to neonatal separation stress

Experimental studies in various animal models have revealed convincing evidence that stressful experience during early developmental periods produces a variety of behavioral, neuroanatomical and endocrine alterations, which are reminiscent of human mental disorders such as depression and various types of anxiety disorders. Since these mental disorders are assumed to be associated with altered GABAergic inhibition in cortical and subcortical brain regions, the current study tested the hypothesis that early postnatal adverse emotional experience (separation stress) interferes with the establishment and functional maturation of distinct inhibitory interneuron populations in different subregions of the medial prefrontal cortex (mPFC) of the precocious rodent degu (Octodon degus). At the age around puberty early stressed animals displayed significantly lower densities of calbindin-D28k-immunoreactive interneurons in the anterior cingulate (down to 79%) and in the precentral medial (down to 64%) subregions of the mPFC compared with age-matched unstressed controls. At this age the densities of two other interneuron types characterized by their expression of the calcium-binding proteins parvalbumin or calretinin remained at control levels. In adulthood, i.e. after an extended period without stress exposure, the density of calbindin-D28k-immunoreactive interneurons in the stressed animals was back to control numbers, whereas parvalbumin-immunoreactive interneurons displayed significantly elevated density in the anterior cingulate (up to 138%) and in the precentral medial cortex (up to 137%) of the stressed animals. In both age groups the density of calretinin- and corticotropin releasing hormone-immunoreactive interneurons did not differ between stressed and control animals, and the prelimbic and infralimbic subregions of the medial prefrontal cortex remained unaffected by stress experience. These results confirm that early adverse emotional experience induces long lasting age-, region- and neuron-specific imbalance of inhibitory systems in some, but not all subregions of the medial prefrontal cortex of the degu.     

Changes in the adaptive behavior of active and passive wistar rats in a water immersion model of depression

Animals with active and passive strategies of adaptive behavior were selected from a population of Wistar rats by testing in a T maze to measure the indexes of behavioral passivity and behavioral activity. After single (stress) or two (stress-restress) water immersions, individual changes in adaptive behavior were used to study the development of post-stress psychopathology and its interaction with the initial behavioral strategy. In the unavoidable aversive environment, active and passive rats developed different types of post-stress depression, only passive individuals fulfilling the criteria of post-traumatic stress disorder. __________ Translated from Zhurnal Vysshei Nervnoi Deyatel’nosti imeni I. P. Pavlova, Vol. 56, No. 4, pp. 543–547, July–August, 2006.     

Comparison of anxiety, depression, and post-traumatic stress symptoms in relatives of ICU patients in an American and an Indian public hospital

Context:

An intensive care unit (ICU) admission of a patient causes considerable stress among relatives. Whether this impact differs among populations with differing sociocultural factors is unknown.

Aims:

The aim was to compare the psychological impact of an ICU admission on relatives of patients in an American and Indian public hospital.

Settings and Design:

A cross-sectional study was carried out in ICUs of two tertiary care hospitals, one each in major metropolitan cities in the USA and India.

Materials and Methods:

A total of 90 relatives visiting patients were verbally administered a questionnaire between 48 hours and 72 hours of ICU admission that included the Hospital Anxiety and Depression Scale (HADS), Beck Depression Inventory-II (BDI-II) and Impact of Events Scale-Revised (IES-R) for post-traumatic stress response.

Statistical Analysis:

Statistical analysis was done using the Mann-Whitney and chi-square tests.

Results:

Relatives in the Indian ICU had more anxiety symptoms (median HADS-A score 11 [inter-quartile range 9-13] vs. 4 [1.5-6] in the American cohort; P<0.0001), more depression symptoms (BDI-II score 14 [8.5-19] vs. 6 [1.5-10.5], P<0.0001) but a comparable post-traumatic stress response (IES-R score>30). 55% of all relatives had an incongruous perception regarding “change in the patient''s condition” compared to the objective change in severity of illness. “Change in worry” was incongruous compared to the perception of improvement of the patient''s condition in 78% of relatives.

Conclusions:

Relatives of patients in the Indian ICU had greater anxiety and depression symptoms compared to those in the American cohort, and had significant differences in factors that may be associated with this psychological impact. Both groups showed substantial discordance between the perceived and objective change in severity of illness.     

Posttraumatic stress disorder in outpatients with depression: Still a missed diagnosis

Comorbidity between major depressive disorder (MDD) and posttraumatic stress disorder (PTSD) is a well-established fact but has been studied little among MDD patients and even less among outpatients. We assessed the prevalence and characteristics of comorbid MDD–PTSD patients in a sample of MDD outpatients in an effort to elucidate possible causes of MDD–PTSD comorbidity. A semistructured clinical interview was applied to 101 outpatients with MDD. Sociodemographic factors, psychiatric history, the presence of PTSD, and MDD–PTSD comorbidity were recorded. The prevalence of MDD–PTSD comorbidity was 38.6%, with 26.7% suffering currently from PTSD. The average duration of PTSD was 16 years, and in most cases (79.5%) PTSD started earlier than or simultaneously with MDD. Only 28.8% of patients with PTSD had a documented diagnosis in their medical record. The most significant factors predicting MDD–PTSD comorbidity were found to be chronic depression, a history of prolonged or repeated trauma, male gender, a younger age at onset of psychological symptoms, lower education, and a lower level of functioning. Our findings indicate that MDD–PTSD comorbidity still remains an overlooked fact. Prolonged trauma seems to be a major risk factor for MDD–PTSD comorbidity, predisposing subjects to PTSD and later on or simultaneously to comorbidity with MDD.     

白桦脂醇对慢性应激抑郁模型大鼠行为及神经营养因子表达的影响*

目的：探讨白桦脂醇对慢性不可预知温和应激抑郁（ CUMS）模型大鼠的抗抑郁作用，为治疗抑郁症提供 基础理论依据。方法：大鼠随机分为正常组、模型组、氟西汀组和白桦脂醇组，采用氟西汀和白桦脂醇干预改进 CUMS模型大鼠，通过行为学观察抑郁行为，TUNEL法检测海马神经元凋亡，HPLC-ECD法检测5- 羟色胺（5-HT）、 去甲肾上腺素（ NE）和多巴胺（ DA）神经递质水平，免疫印迹检测脑源性神经营养因子（ BDNF）、神经营养 蛋白3（NT-3）和神经生长因子（ NGF）蛋白水平。结果：氟西汀组和白桦脂醇组较模型组大鼠的体质量在3、4 周增加，且在4 周时白桦脂醇组较氟西汀组的大鼠体质量增加；氟西汀组和白桦脂醇组较模型组大鼠悬尾静止时 间、强迫游泳不动时间均延长，且氟西汀组较白桦脂醇组明显延长；氟西汀组和白桦脂醇组较模型组海马凋亡细 胞数下降，且白桦脂醇组高于氟西汀组；氟西汀组和白桦脂醇组较模型组大鼠脑组织中5-HT、NE和DA含量均 减少，且氟西汀组较白桦脂醇组减少；氟西汀组较模型组大鼠脑组织BDNF、NT-3 和NGF 蛋白相对表达水平均 降低，氟西汀组较白桦脂醇组降低。结论：白桦脂醇能够改善CUMS模型大鼠的抑郁行为，且对其海马神经元具 有一定保护作用。