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61.
Recording cerebellar neuron activities in swimming goldfish 总被引:1,自引:0,他引:1
ABSTRACT: Neuronal activities were investigated in the cerebellum of immobilized and swimming goldfish Carassius auratus . Extracellularly recorded neural activities of the cerebellum in immobilized goldfish were characterized and classified into five types. Based on the waveforms and recording depths, these five neural activity types were estimated to originate from three identified classes of cerebellar neurons: Purkinje cells, eurydendroid cells, and granule cells. Chronic recording of cerebellar neuron activities in unrestrained goldfish was performed for more than 100 h. During the chronic recordings, a submersible amplifier attached to the goldfish head, and a multielectrode array developed for the present study were used. Neuronal activities in the cerebellum of free-swimming fish could also be classified into five types as in the immobilized condition. Firing patterns of two neurons identified as Purkinje cells and eurydendroid cells were analyzed during turning movements of the goldfish. The firing patterns of these neurons changed in relation to turning movements. Although some improvements are required, the chronic recording method developed in the present study can be applied to further investigations concerning the direct relationship between brain neural activities and certain behavior. 相似文献
62.
The endemic, anadromous cyprinidChalcalburnus tarichi is the only fish species known to occur in alkaline Lake Van (Eastern Anatolia, Turkey). EightC. tarichi were maintained individually in Lake Van water (17 – 19°C; pH 9.8; 153 mEq·I–1 total alkalinity; 22 total salinity) and tank water samples analyzed for 24 h in 2 to 4 h intervals. At zero time, < 1µM ammonia was present and urea was undetectable in the tank water; at 24 h, total ammonia and urea made up 114±32 and 35±25µM, respectively. Over the experimental period, ammonia-N and urea-N excretion averaged 1041±494 and 607±169moles·kg–1 fish·h–1, respectively. The extent of urea excretion was highly variable between specimens. Uric acid excretion was not detectable.Urea was present at high concentrations in all tissues and plasma (25 – 35moles·g–1·ml–1) of freshly caughtC. tarichi; total ammonia content of the tissues was by a factor of 1.9 (liver) to 3.0 (brain) lower. High arginase activity (2.4±0.2 U·min–1·g–1) was detected in the liver ofC. tarichi but ornithine carbamoylphosphate transferase, a key enzyme of the ornithine-urea-cycle, was absent. Ureagenesis is likely through degradation of arginine and/or uricolysis. High glutamine synthetase activity (11±0.6 U·min–1·g–1) and low ammonia content in brain suggest that, like other teleosts,C. tarichi has an efficient ammonia detoxification in the brain, but in no other tissue.Nitrogenous waste excretion at alkaline pH is discussed. The ability ofC. tarichi to excrete high levels of ammonia at extremely alkaline pH is unique among teleosts studied so far. The mechanism of ammonia excretion under Lake Van conditions remains to be elucidated. 相似文献
63.
64.
Ylva Lind 《Fish physiology and biochemistry》1992,9(5-6):409-415
In June, July, and September the activities of five enzymes involved in the carbohydrate and fatty acid metabolism, namely phosphofructokinase (PFK), lactate dehydrogenase (LDH), citrate synthase (CS), cytochrome oxidase (cyt ox) and 3-hydroxy-acyl-CoA dehydrogenase (HAD), were measured in the heart, liver, red muscle, white muscle, and gill lamellae of crucian carp (Carassius carassius). LDH activity was measured in both reducing (LDHr) and oxidizing (LDHo) directions.The PFK activity in red and white muscle increased significantly between July and September indicating a preparation to winter anoxia by an increased glycylytic capacity in these organs. The HAD activity of the liver had increased significantly (by more than 50%) by September, also a preparation to winter anoxia as HAD is used in the reversed -oxidation (chain elongation of fatty acids). The LDHr and cyt ox activities in the heart and white muscle were highest in July. This shows that both the anaerobic and aerobic capacities are elevated in mid-summer when water temperature is high and oxygen concentration of the water could fluctuate greatly. The LDHo and CS activities in gill lamellae were lowest in July. The results show that the metabolism of crucian carp is under seasonal influence and that a preparation to winter hypoxia/anoxia could be detected in September. 相似文献
65.
A group of Atlantic salmon (Salmo salar) was followed through their first year of maturation and spawning. At monthly intervals, starting with juvenile fish in December, 5–7 fish of each sex were killed, and liver and plasma were sampled. The last sampling point was of spawning fish in November a year later. Variables in the cytochrome P450 (P450) system were studied in hepatic microsomes, and estradiol 17 was measured in the plasma of females to assess the maturational status. The P450 1A1-mediated 7-ethoxyresorufin O-deethylase (EROD) started at high levels in winter, but decreased to non-detectable activities in pre-spawning females. Decreases, but not to the same extent, were also observed during this period in total cytochrome P450, cytochrome b5, NADPH-cytochrome P450 reductase, and in the content of two immunochemically determined P450 isozymes. At the same time, LSI levels increased in maturing females (starting in July), and GSI levels increased in both sexes (starting in May). Sex specific differences were observed in pre-spawning fish in September and October, with levels of total P450, b5, NADPH-cytochrome P450 reductase, EROD and P450 isozymes significantly lower in females. At the same time, plasma estradiol-17 levels reached peak values in females. The results point to the important role of sex steroids such as estradiol-17 as major factors in the regulation of final sexual maturation. However, this study also indicates that there may be estradiol-17 independent events of equal importance in the early stages of gonadal maturation that may involve the P450 system. The changes observed in the P450 system (as a major drug and steroid metabolizing system) of Atlantic salmon during sexual maturation may be of importance both in the endogenous transduction of hormonal signals, and as a pharmacological basis for designing therapeutic treatment of diseases in the aquaculture industry.Parts of this work were presented at the 5th International Symposium on Responses of Marine Organisms to Pollutants, April 1989 in Plymouth, United Kingdom (Larsen and Goks\/oyr 1989). 相似文献
66.
Nitric oxide synthase (NOS) is an enzyme that catalyzes the formation of nitric oxide (NO), an important biological messenger from L-arginine. There are considerable evidence showing the expression of NOS in mammalian tissues. Information on distribution of NOS activities in various organs and tissues of fish is rare. Non-functional NOS activities were documented in fish semi-quantitatively either by an indirect nicotine-adenine-dinucleotide-phosphate diaphorase (NADPH-d) activity histochemical staining method or by an immunohistochemical method using a cross-reacting antibody to brain NOS. Report on the functional levels of NOS activities in fish is lacking. This report represent the first attempt to document the functional NOS levels in various fish organs and tissues. Constitutive NOS (cNOS) activities in various organs of big-head carp (Aristichthys nobilis) was measured by a chemiluminescence method with a detection limit as low as 10 mol of NO produced. It was found that constitutive NOS activity was highest in the brain, followed by the intestine, stomach, retina, olfactory lobe, swim bladder, skeletal muscle, heart, kidney, ovary and liver. NOS activity could not be detected in the gill filaments. Omission of NADPH in the reaction mixture caused a 57–100% decrease in cNOS activities. However, omission of arginine in the mixture only caused a 56–87% drop in cNOS activities. When compared with cNOS activities documented from other species, a similar pattern of cNOS activities in the various organs and tissues of big-head carp could be seen. 相似文献
67.
Algal-oligosaccharide-lysates prepared by two bacterial agarases stepwise hydrolyzed and their anti-oxidative properties 总被引:1,自引:0,他引:1
Twenty algal-oligosaccharide-lysates (AOLs), derived from six agars and four algal polysaccharide extracts (APEs), were treated
first with agarases with 250 or 500 agarase activity units (AU), which were produced from the agar-liquefying bacterial strain
Pseudomonas vesicularis MA103, named MA103-agarases. The AOLs were then treated with agarases (250 or 500 AU) derived from the agar-softening bacterial
strain Aeromonas salmonicida MAEF 108, named MAEF 108-agarases. Anti-oxidative properties of the AOLs were evaluated by five in vitro methods. The AOL obtained from the APE of Porphyra dentate, digested by 250 AU of MA 103-agarases, and by 250 AU of MAEF 108-agarases, designated as A250-Por, showed better results than the 19 other AOLs. This result is in accordance with the level of soluble total polyphenols
(STP) of A250-Por, which was also higher than the remainder of the AOLs tested. The AOL derived from the APE of P. dentate, digested by 500 AU of MA103-agarases and then 500 AU of MAEF108-agarases, and designated as B500-Por, displayed the second highest data in four potential evaluation methods, except in H2O2 scavenging capacity. In this study, certain agars or APEs digested by specific agarases can present an increasing antioxidative
capacity. These agars include Bitek agar, Agar powder, Bacteriological, Agar Bacteriological, and Guanghui agar, plus APEs
of Gracilaria sp. and Monostroma nitidum decomposed stepwise by two agarases. The fraction of polyphenols (<1 kDa) that were derived from A250-Por showed anti-oxidative activities on α, α-diphenyl-β-picrylhydrazyl (DPPH) assay and reducing power determination, while
the remaining four agar-lytic fractions obtained from A250-Por did not exhibit anti-oxidative activity. This phenomenon may suggest that anti-oxidative properties of AOLs originate
in polyphenols. Algal-oligosaccharide-lysates may have potential use as a health food. 相似文献
68.
通过大田试验研究施用不同有机肥对香草兰生长,叶绿素荧光特性及土壤酶活性的影响。结果表明:有机肥和生物有机肥混合施用的处理香草兰茎蔓和叶片干重显著高于施用牛粪的处理;施用生物有机肥和有机肥的处理香草兰叶片表观电子光合传递速率(ETR)和实际光化学效率(Yield)无显著性差异,但均显著高于施用牛粪的处理;有机肥和生物有机肥混合施用的处理土壤酸性磷酸酶、脲酶和蔗糖酶活性显著高于施用牛粪的处理。综上所述,有机肥和生物有机肥配合施用可显著促进香草兰生长,提高香草兰的光能利用效率和土壤酶活性。 相似文献
69.
为了解轮耕对土壤酶活性的影响,采用田间定位试验,比较和分析了秸秆还田和不还田条件下,连续3年常规耕作(3C)、1年深翻+2年常规耕作(DP2C)、2年深翻+1年常规耕作(2DPC)和连续3年深翻(3DP)处理的冬小麦田土壤酶活性时空变化特点。结果表明,秸秆还田和深翻均可提高0~40cm土层土壤蔗糖酶、脲酶、碱性磷酸酶和过氧化氢酶的活性,其中秸秆还田后平均增幅分别为24.92%、9.20%、6.66%和11.04%,经深翻处理后平均增幅分别为5.33%、6.26%、2.02%和3.43%。随着土层深度增加,各处理土壤酶活性逐渐降低,2DPC和3DP处理相对3C处理20~40cm土层4种土壤酶活性降低幅度较小。秸秆还田配合2DPC、3DP土壤耕作处理不仅能提高酶活性,也有利于酶在土壤中均匀分布。 相似文献
70.
Romain Gastineau Fran?ois Turcotte Jean-Bernard Pouvreau Michèle Moran?ais Jo?l Fleurence Eko Windarto Fiddy Semba Prasetiya Sulastri Arsad Pascal Jaouen Mathieu Babin Laurence Coiffard Céline Couteau Jean-Fran?ois Bardeau Boris Jacquette Vincent Leignel Yann Hardivillier Isabelle Marcotte Nathalie Bourgougnon Réjean Tremblay Jean-Sébastien Deschênes Hope Badawy Pamela Pasetto Nikolai Davidovich Gert Hansen Jens Dittmer Jean-Luc Mouget 《Marine drugs》2014,12(6):3161-3189
In diatoms, the main photosynthetic pigments are chlorophylls a and c, fucoxanthin, diadinoxanthin and diatoxanthin. The marine pennate diatom Haslea ostrearia has long been known for producing, in addition to these generic pigments, a water-soluble blue pigment, marennine. This pigment, responsible for the greening of oysters in western France, presents different biological activities: allelopathic, antioxidant, antibacterial, antiviral, and growth-inhibiting. A method to extract and purify marennine has been developed, but its chemical structure could hitherto not be resolved. For decades, H. ostrearia was the only organism known to produce marennine, and can be found worldwide. Our knowledge about H. ostrearia-like diatom biodiversity has recently been extended with the discovery of several new species of blue diatoms, the recently described H. karadagensis, H. silbo sp. inedit. and H. provincialis sp. inedit. These blue diatoms produce different marennine-like pigments, which belong to the same chemical family and present similar biological activities. Aside from being a potential source of natural blue pigments, H. ostrearia-like diatoms thus present a commercial potential for aquaculture, cosmetics, food and health industries. 相似文献