Depression Model Group Research Articles

The anti-depression effects of docosahexaenoic acid and its effects on the expression of caspase-3 in hippocampal neuron

Objective To explore the therapeutic effects of docosahexaenoic acid(DHA) on depression, and its influence on the expression of caspase-3 in hippocampal neuron. Methods A total of 50 SD rats were randomly divided into 5 groups (control, model, fluoxetine, DHA, combination group), 10 rats in each group. SD rats were given different stimuli for 21 days to set up unforeseeable chronic stress depression model. After 21 days, the changes of behaviors in forced swimming test and morphology change in CA1, CA2 and CA3 in hippocampal neurons were observed. The change of caspase-3 in hippocampal neuron were detected by real-time PCR and western blot. Results Behavioral results showed that the swimming immobility time in depression model group, DHA group and combination group were respectively(113.33±9.50)s, (81.67±7.68)s and(73.00±8.54)s.Compared with depression model group, the DHA group and DHA combined with fluoxetine group obviously reduced the swimming immobility time of rats(t=8.164, 9.855, P<0.01). HE stain result showed DHA could partly recovered the number of hippocampal neurons in CA1, CA2 and CA3 and reduced apoptosis. qPCR and WB results showed DHA alone or DHA combined with fluoxetine could inhibit mRNA and protein level of caspase-3 in hippocampal neurons. Conclusion DHA can improve depression to a certain extent in a rat model of unforeseeable chronic stress depression, which might work through inhibition of neuron apoptosis and caspase-3 expression in hippocampal neurons. Key words: Docosahexaenoic acid; Depression; Hippocampal neuron; Apoptosis; Caspase-3

Pharmacokinetic alternation of mitiglinide in depression model rats (657.3)

Many diabetes patients suffer from wild to severe depression. It is unclear that depression might alter the drug metabolic process of the hypoglycemic agents or not. We conducted an animal experiment to study the impact. Eighteen Sprague‐Dawley rats were randomized into depression model group and control group. The 9 depression rats were established by exposing to chronic unpredicted mild stresses (CUMS) for 8 weeks. Open‐field test and 5‐HT levels were assayed to evaluate the depression. All rats were given 2.5mg/kg of mitiglinide (MGN) per os. MGN plasma concentration was measured by HPLC‐MS/MS. Statistical moment analysis was processed with DAS software. Open‐field test and 5‐HT levels measurement results confirmed the depression model. Cmax, Tmax, AUC0→∞, MRT0→∞, and T1/2z were reduced while CLz/F was increased in depression model rats compared to control rats. These preliminary results suggest that depression might alter the drug metabolic process of MGN.Grant Funding Source: Supported by Shanghai Fengxian Science and Technology Research Project

Chronic unpredictable mild stress impairs erythrocyte immune function and changes T-lymphocyte subsets in a rat model of stress-induced depression

Stress has been shown to suppress immune function and increase susceptibility to inflammatory and psychiatric diseases. This study sought to investigate the changes in erythrocyte immune functions and T-lymphocyte subsets and to explore the mechanism implicated in the process of stress-induced depression by employing a rat depression model induced by chronic unpredictable mild stress (CUMS). The body weights and behavioral changes of the rats were recorded, and plasma corticosterone levels were determined by radioimmunoassay. Erythrocyte immune function and T-lymphocytes subsets were respectively measured by the method of yeast rosette and flow cytometry at different time intervals, and their relationship was analyzed. Results indicated that a reduction was observed in the following: the rats’ crossing and rearing movement times, the volume of sucrose intake and the preference for sucrose in the depression model group. Plasma corticosterone levels were elevated; the rate of E-C3bR decreased, and E-IC was increased. Some alterations in the percentage of T-lymphocytes and IL-2 appeared in the depression model group and some relationships existed between these parameters. Collectively, these findings disclose that long-time stress could induce changes in rat behavior and activities through an effect on erythrocyte immune functions and T-lymphocyte subsets.

Observation on morphology and nerve growth factor expression in nasal mucosal of depression rats

To establish the rat model of depression and observe its morphological changes and nerve growth factor (NGF) expression in nasal mucosal. Thirty SD rats were divided into depression model group and normal controls with 15 rats in each group. The rat depression model were made by application of chronic unforeseeable medium stress stimulating. Behavior change were observed with open box experiment(open field) and humoral consumption-experiments (sucrose consumption), After being sacrificed, the nasal mucosal were taken for HE and NGF immunohistochemical study. The difference of nasal mucosal NGF protein between two groups were examined with medical digital image analysis technology. There were no swelling and inflammatory cells infiltrating in nasal mucosal of normal group, but 53% nasal mucosal of depression model were observed such morphological changes. Th NGF immunohistochemical staining were negative in normal group but positive in 53% depression model group. There were significant differences between two groups (P < 0.01). Depression rats may appear rhinitis symptoms under long-term stress stimulating. NGF may exert immunoregulatory effects, stimulate the immune cell proliferation and gathering, induce various media release, increase the sensitivity of nerve fibers itself and the producing of neuropeptide, promote the formation of nerve source inflammation and increase the reactivity of nasal mucosa.

Effect of Chaihu Shugan San and its components on expression of ERK1/2 mRNA in the hippocampus of rats with chronic mild unpredicted stress depression.

To explore the antidepressant effect and mechanism of Chaihu Shugan San (CHSGS) composition, a compound traditional Chinese herb medicine and its components. Rats were randomly divided into 6 groups: normal control group, model control group, a CHSGS group, a component I group, a component II group and a fluoxetine control group. The depression model was replicated by chronic unpredictable mild stress and single house for 28 d. Behavioral scores of the rats were detected by Open-field test and sucrose solution consumption test, and ERK1/2 mRNA expression in the hippocampus tissue was assayed by real-time fluorescent quantitative PCR. ERK1/2 mRNA expression was down-regulated in the depression model group compared with the normal control group (P<0.01). Compared with the model group, ERK1/2 mRNA expression in the CHSGS group and fluoxetine group was both up-regulated (P<0.05 or P<0.01); and only ERK1 mRNA expression in the component I group was up-regulated (P<0.05). No significant difference existed between the component II group and the model group (P>0.05). Isolated-living condition and chronic mild unpredictable stress can down-regulate the expression of ERK1/2 mRNA in the hippocampus tissue. CHSGS may exert an antidepressant effect through increasing the expression of ERK1/2 mRNA in the hippocampus, component I may play an important role in its antidepression effect, while compatibility of the use of component II can enhance the antidepressant efficacy.

Empirical Study of Changes of Pre-Menstrual Syndrome Model Rats with Liver-qi Invasion and Liver-qi Depression in Peripheral Blood, Sexual Hormones, Different Encephalic Regions and Accommodate Hormones

Abstract This work successfully used model rats with Pre-Menstrual Syndrome (PMS) liver-qi invasion and liver-qi depression in the early development days to detect the content levels of estradiol (E2), progesterone (P) and prolactin (PRL) in their blood serums and different encephalic regions, to explore the micro-mechanism of the syndrome of the liver failing to maintain the normal flow of qi. 40 rats with estrous cycles not in accepting time were selected and divided randomly into five groups: the normal control group, PMS liver-qi invasion model group, PMS liver-qi depression model group, PMS liver-qi invasion medication-administered group and PMS liver-qi depression medication-administered group. Emotional stimulation and multiple factors combination were used to prepare the PMS liver-qi invasion model. Chronic stress constraints were used to prepare the PMS liver-qi depression model. Jingqianping granules were administered to rats to interfere with the PMS liver-qi invasion mode, and Jingqianshu granules were administered to rats to interfere with the PMS liver-qi depression mode. Radioimmunity was used to determine the content levels of E2, P and PRL in the blood serum and centrum, and to compare and analyze the differences among the five groups. In the open-field experiment, the crossing scores, rearing scores and open-field experiment total scores of rats in the PMS liver-qi invasion model group increased remarkably (P

Effect of Chaiqin Wendan Decoction on the behaviors of chronic stress-induced depression mice

目的 研究中药柴芩温胆汤对慢性轻度不可预见性应激和孤养结合抑郁模型小鼠行为的影响.方法 将60只雄性小鼠随机分为空白对照组、模型组、阿米替林对照组、柴芩温胆汤低剂量组、柴芩温胆汤高剂量组,每组12只.用抖笼法检测小鼠的行为学改变.结果 抑郁模型小鼠的自主活动 [(82.50±14.98)次]与空白对照组[(336.00±46.85)次]比较明显减少(P＜0.01),其激惹次数[(5.75±0.95)次]与空白对照组比较显著增加(P＜0.01);高、低剂量柴芩温胆汤、阿米替林均能明显改善小鼠的自主活动和降低激惹次数,但在改善自主活动方面柴芩温胆汤高剂量[(323.75±63.40)次]作用更为显著,与阿米替林组[(254.25±28.34)次]和柴芩温胆汤低剂量组[(251.50±15.87)次]均差异有显著性(P＜0.01);而在降低激惹次数方面阿米替林[(0.28±0.60)次]和高剂量柴芩温胆汤[(0.25±0.58)次]作用相当(P＞0.05),与低剂量柴芩温胆汤[(1.25±0.50)次]比较均差异有显著性(P＜0.01).结论 中药柴芩温胆汤能明显改善抑郁模型小鼠的行为,具有抗抑郁作用,并存在一定的量效关系。

Expression of tyrosine hydroxylase in locus coeruleus of depression model rats

目的 采用慢性应激复制抑郁大鼠模型,观测抑郁模型大鼠蓝斑酪氨酸羟化酶的表达,探讨抑郁症的发病机制.方法将大鼠随机分为正常组、模型组,运用慢性轻度不可预见性应激配合孤养复制抑郁模型,以免疫组化方法研究抑郁模型大鼠海马蓝斑酪氨酸羟化酶的表达.结果与正常大鼠比较,模型组蓝斑酪氨酸羟化酶的表达下调,其平均灰度值分别为(62.16±2.43)和(89.00±1.83)(P <0.05) .结论抑郁模型大鼠蓝斑酪氨酸羟化酶的表达较正常大鼠显著减少。

Decreased expression of the mRNA for somatostatin in the periventricular nucleus of depression-model rats

Expression of the mRNA for somatostatin (SRIF) in the periventricular nucleus (PeN), the level of SRIF in the stalk-median eminence (SME) and the concentration of growth hormone (GH) in the plasma were examined in depression-model rats in an attempt to confirm the hypothesis that SRIF neurons in the hypothalamus are hypofunctional in this model. We exposed male Wistar rats to intermittent walking stress for two weeks and then we measured their spontaneous running activity for 12 days. We divided the rats into a depression-model group and a partial-recovery group according to the spontaneous running activity of each rat after the termination of exposure to stress. Expression of SRIF mRNA in the PeN of the hypothalamus was monitored by in situ hybridization and relative levels were determined with an image analysis system. The relative level of expression of SRIF mRNA in the PeN was lower in rats in the depression-model group than in the control group and the partial-recovery group. The level of SRIF in the SME was lower and the plasma concentration of GH was higher in the depression-model group than in the other groups. Our findings suggest that reduced expression of mRNA for SRIF in the PeN might be associated with the pathophysiology of rats with this particular model of depression.

Enhanced response of growth hormone to growth hormone-releasing hormone and a decreased content of hypothalamic somatostatin in a stress-induced rat model of depression.

This study was designed to evaluate changes in the hypothalamic somatostatin-growth hormone axis (SRIF-GH axis) in a stress-induced rat model of depression. We exposed male Wistar rats to intermittent walking stress for two weeks, and then measured their spontaneous running activities for 12 days. We divided the rats into the depression-model group and the partial recovery group according to their spontaneous running activities after the termination of exposure to stress. We examined the secretion of GH from the anterior pituitary by injecting human GH-releasing hormone (hGHRH) with intracardiac cannulae or by applying hGHRH or SRIF to isolated anterior pituitaries using a perifusion system. We also determined SRIF content in the stalk-median eminence (SME) and the plasma concentration of GH. In the depression-model group, intracardiac administration of hGHRH caused the enhanced release of GH into plasma, while application of hGHRH or SRIF to the anterior pituitary in vitro had similar effects on GH release in the control and partial recovery groups. Furthermore, the SRIF content was decreased in the SME and the GH concentration was increased in plasma. The partial recovery group gave similar values to the control group. The enhanced response of GH to hGHRH in the depression-model group might have been caused by the reduced content of SRIF in the SME in view of the unchanged response of GH to the infusion of hGHRH or SRIF in the perifusion system.