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81.
慢性应激不同方式对大鼠血清皮质酮的影响 总被引:1,自引:0,他引:1
目的:比较慢性应激不同方式对生理状态大鼠血清皮质酮水平的影响,研究机体慢性应激反应的整体性适应特征。方法:采用连续4周的适宜游泳、束缚和二者复合的三种应激方式后,测定大鼠血清皮质酮基础含量,分析不同慢性应激方式对皮质酮水平的影响。结果:血清皮质酮水平与对照组比较,复合组无显著性差异;游泳组虽升高但无显著性;束缚组升高有显著性意义。结论:束缚可致大鼠血清皮质酮水平增高;初步认定游泳与束缚复合慢性应激方式可能对机体的整体适应性能具有积极意义。 相似文献
82.
The morphology of the swim bladder and inner ear of the nurseryfish, Kurtus gulliveri, appear adapted for enhanced pressure wave reception. The saccule is enlarged and surrounded by very thin bone and two large fontanelles that would present reduced resistance to pressure waves. The swim bladder is elaborate, with six dorsolaterally projecting pairs of lobes that are tightly encased in ribs and an additional caudally projecting pair of lobes encased in the first hemal spine. The ribs and musculature surrounding the swim bladder laterally are very thin, so that four or five "rib windows" are readily apparent on back-lit specimens. This swim bladder-rib configuration would also present reduced resistance to pressure waves to enhance function as a peripheral auditory structure. However, high-resolution X-ray computed tomography and dissection reveal no anterior projections of the swim bladder that could serve as a mechanical coupling to the inner ear. The posterior lateral line nerve is well developed and lies directly over the tips of the ribs encasing the swim bladder lobes. This nerve is not, however, associated with a lateral line canal and a lateral line canal is absent on most of the body. We hypothesize that the posterior lateral line nerve transmits mechanosensory information from the swim bladder. 相似文献
83.
L. M. Logan‐Chesney M. J. Dadswell R. H. Karsten I. Wirgin M. J. W. Stokesbury 《Journal of fish biology》2018,92(4):929-943
Atlantic sturgeon Acipenser oxyrinchus surfacing behaviour was investigated in Minas Basin (45° 20′ N; 64° 00′ W) and the Bay of Fundy with pop‐up satellite archival tags (MiniPAT) measuring physical variables (pressure, temperature, light ) . Of six tags deployed during June and July, five provided pop‐up locations and two were recovered after c. 4 months. Analysis of recovered archival data revealed that the frequency of surfacing events was highest (78·9%) when A. oxyrinchus were in Minas Basin at depths <10 m. Surfacing frequency decreased substantially when fish migrated into greater depths of the Bay of Fundy (>40 m). The tidal cycle in Minas Basin had a significant relationship to surfacing frequency, with the most surfacing events (49·5%) occurring on the flood tide, from mid‐ to high‐tide. Surfacing events ranged from 0–12 a day and the maximum number occurred between 2300 and 0300 hours. Maximum surfacing ascent speeds ranged from 0·50 to 4·17 m s?1 and maximum descent speeds ranged from 0·17 to 3·17 m s?1. Buoyancy control, by gulping air to inflate the gas bladder, is proposed as the main reason for surfacing behaviour in A. oxyrinchus. 相似文献
84.
Katarzyna Pańczyk Karolina Pytka Magdalena Jakubczyk Anna Rapacz Kinga Sałat Anna Furgała Agata Siwek Monika Głuch-Lutwin Anna Gryboś Karolina Słoczyńska Elżbieta Pękala Paweł Żmudzki Adam Bucki Marcin Kołaczkowski Dorota Żelaszczyk Henryk Marona Anna M. Waszkielewicz 《Bioorganic & medicinal chemistry letters》2018,28(11):2039-2049
Aim of the study was evaluation of anxiolytic, antidepressant, anticonvulsant and analgesic activity in a series of a consistent group of compounds. A series of eleven new N-(phenoxyalkyl)- or N-{2-[2-(phenoxy)ethoxy]ethyl}piperazine derivatives has been obtained. Their affinity towards 5-HT1A, 5-HT2A, 5-HT6, 5-HT7, D2 and α1 receptors has been assessed, and then functional assays were performed. The compounds were evaluated in mice, i.p. for their antidepressant-like (forced swim test), locomotor, anxiolytic-like (four-plate test) activities as well as – at higher doses – for anticonvulsant potential (MES) and neurotoxicity (rotarod). Two compounds (3, 6) were also evaluated for their analgesic activity in neuropathic pain models (streptozocin test, oxaliplatin test) and they were found active against allodynia in diabetic neuropathic pain at 30?mg/kg. Among the compounds, anxiolytic-like, anticonvulsant or analgesic activity was observed but antidepressant-like activity was not. One of the two most interesting compounds is 1-{2-[2-(2,4,6-trimethylphenoxy)ethoxy]ethyl}-4-(2-methoxyphenyl)piperazine dihydrochloride (9), exhibiting anxiolytic and anticonvulsant activity in mice, i.p. 30 min after administration (at 2.5?mg/kg and ED50?=?26.33?mg/kg, respectively), which can be justified by the receptor profile: 5-HT1A Ki?=?5?nM (antagonist), 5-HT7 Ki?=?70?nM, α1 Ki?=?15?nM, D2 Ki?=?189?nM (antagonist). Another interesting compound is 1-[3-(2,4,6-trimethylphenoxy)propyl]-4-(4-methoxyphenyl)piperazine dihydrochloride (3), exhibiting anxiolytic, anticonvulsant and antiallodynic activity in mice, i.p., 30?min after administration (at 10?mg/kg, ED50?=?23.50?mg/kg, at 30?mg/kg, respectively), which can be related with 5-HT1A weak antagonism (Ki?=?146?nM), or other possible mechanism of action, not evaluated within presented study. Additionally, for the most active compound in the four-plate test (7), molecular modeling was performed (docking to receptors 5-HT1A, 5-HT2A, 5-HT7, D2 and α1A). 相似文献
85.
86.
Electroconvulsive therapy is considered an effective treatment for severe depression. However, the mechanisms for its long-lasting antidepressant efficacy are poorly understood. In the present study, we investigated changes of the immobility time in the forced swim test and brain-derived neurotrophic factor (BDNF) protein after withdrawal from 14-day repeated electroconvulsive stimuli (ECS, 50 mA, 0.2 s) in rats. Immobility time in the forced swim test was markedly decreased 6 h after withdrawal following 14-day ECS treatment. Thereafter, prolongation of the withdrawal period gradually diminished the decreasing effect of immobility time, but significant effects persisted for up to 3 days after the withdrawal. Locomotor activity in the open-field test increased 6 h after withdrawal from the ECS treatment, and the enhanced effect persisted for at least 7 days. The BDNF protein level in the hippocampus was markedly increased 6 h after the withdrawal, and remained high for at least 7 days. These findings provide further evidence that repeated ECS has long-lasting effect on increase in BDNF and locomotor activity and decrease in immobility time in the forced swim test. 相似文献
87.
(1) The treatment of choice for Parkinson’s disease (PD) is 3,4-dihydroxyphenylalanine (L-DOPA) with peripheral decarboxylase
inhibitor, but long-term therapy leads to motor and psychiatric complications. In the present study we investigated 5-hydroxytryptamine
(5-HT) and dopamine concentrations in serotonergic and dopaminergic nuclei following chronic administration of L-DOPA to find
whether the neurotransmitter synthesis in these brain areas are compensated. (2) Rats were administered L-DOPA (250 mg/kg)
and carbidopa (25 mg/kg) daily for 59 and 60 days, and killed on the 60th day, respectively at 24 h and 30 min after the last
dose. L-DOPA, norepinephrine, 5-HT, 5-hydroxyindoleacetic acid (5-HIAA), dopamine, homovanillic acid (HVA), and 3,4-dihydroxyphenylacetic
acid (DOPAC) were measured in striatum, nucleus raphe dorsalis (NRD), nucleus accumbens (NAc), substantia nigra, cerebellum,
and cortex employing HPLC-electrochemical procedure. (3) Prolonged treatment of L-DOPA caused depression in the animals as
revealed in a forced swim test. Serotonin content was significantly decreased in all brain regions studied 30 min after long-term
L-DOPA, except in NAc. The cortex and striatum showed lowered levels of this indoleamine 24 h after 59 doses of L-DOPA. Dopamine,
HVA, and DOPAC concentrations were significantly higher in all the regions studied after 30 min, and in the cerebellum after
24 h of L-DOPA. The levels of DOPAC were elevated in all the brain areas studied 24 h after prolonged L-DOPA treatment. (4)
The present results suggest that long-term L-DOPA treatment results in significant loss of 5-HT in serotonergic and dopaminergic
regions of the brain. Furthermore, while L-DOPA metabolism per se was uninfluenced, dopamine synthesis was severely impaired
in all the regions. The imbalance of serotonin and dopamine formation may be the cause of overt cognitive, motor, and psychological
functional aberrations seen in parkinsonian patients following prolonged L-DOPA treatment. 相似文献
88.
Post-partum stress and depression (PPD) have a significant effect on child development and behavior. Depression is associated with hypercortisolism in humans, and the fluctuating levels of hormones, including corticosterone, during pregnancy and the post-partum, may contribute to PPD. The present study was developed to investigate the effects of high-level corticosterone (CORT) post-partum in the mother on postnatal neurogenesis and behavior in the offspring. Sprague-Dawley dams were treated with either CORT (40 mg/kg) or sesame oil injections daily for 26 days beginning the day after giving birth. Dams were tested in the forced swim test (FST) and in the open field test (OFT) on days 24-26 post-partum. Results showed that the dams exposed to CORT expressed "depressive-like" behavior compared to controls, with decreased struggling behavior and increased immobility in the FST. To investigate the effects of treatment on hippocampal postnatal cell proliferation and survival in the offspring, males and females from treated dams were injected with BrdU (50 mg/kg) on postnatal day 21 and perfused either 24 h (cell proliferation) or 21 days (cell survival) later. Furthermore, male and female offspring from each litter were tested in adulthood on various behavioral tests, including the forced swim test, open field test, resistance to capture test and elevated plus maze. Intriguingly, male, but not female, offspring of CORT-treated dams exhibited decreased postnatal cell proliferation in the dentate gyrus. Both male and female offspring of CORT-treated dams showed higher resistance to capture and greater locomotor activity as assessed in the open field test. As high levels of CORT may be a characteristic of stress and/or depression, these findings support a model of 'CORT-induced' post-partum stress and possibly depression and demonstrate that the offspring of affected dams can exhibit changes in postnatal neurogenesis and behavior in adulthood. 相似文献
89.
16p11.2 deletion syndrome mice perseverate with active coping response to acute stress – rescue by blocking 5‐HT2A receptors 下载免费PDF全文
Chris M. Panzini Daniel G. Ehlinger Adele M. Alchahin Yueping Guo Kathryn G. Commons 《Journal of neurochemistry》2017,143(6):708-721
90.
Michele B. Halvorsen Brandon M. Casper Frazer Matthews Thomas J. Carlson Arthur N. Popper 《Proceedings. Biological sciences / The Royal Society》2012,279(1748):4705-4714
Pile-driving and other impulsive sound sources have the potential to injure or kill fishes. One mechanism that produces injuries is the rapid motion of the walls of the swim bladder as it repeatedly contacts nearby tissues. To further understand the involvement of the swim bladder in tissue damage, a specially designed wave tube was used to expose three species to pile-driving sounds. Species included lake sturgeon (Acipenser fulvescens)—with an open (physostomous) swim bladder, Nile tilapia (Oreochromis niloticus)—with a closed (physoclistous) swim bladder and the hogchoker (Trinectes maculatus)—a flatfish without a swim bladder. There were no visible injuries in any of the exposed hogchokers, whereas a variety of injuries were observed in the lake sturgeon and Nile tilapia. At the loudest cumulative and single-strike sound exposure levels (SELcum and SELss respectively), the Nile tilapia had the highest total injuries and the most severe injuries per fish. As exposure levels decreased, the number and severity of injuries were more similar between the two species. These results suggest that the presence and type of swim bladder correlated with injury at higher sound levels, while the extent of injury at lower sound levels was similar for both kinds of swim bladders. 相似文献