Effect of adrenalectomy and corticosterone replacement on prepulse inhibition and locomotor activity in mice

1 Stress is a risk factor in psychiatric illnesses such as schizophrenia. The aim of the present study was to investigate the effect of different circulating levels of the adrenal steroid corticosterone (CORT) on locomotor hyperactivity and prepulse inhibition of acoustic startle, two behavioural animal models of aspects of schizophrenia. 2 Male C57BL/6J mice (n = 10 per group) were anaesthetised with isoflurane and sham-operated or adrenalectomised (ADX). ADX mice were implanted with 50 mg pellets consisting of 100% cholesterol, or 2, 10 or 50 mg of CORT mixed with cholesterol. CORT pellet implantation dose dependently increased plasma CORT levels 3 weeks after surgery. Starting 1 week after surgery, mice were tested for prepulse inhibition after injection of saline or 5 mg kg(-1) of haloperidol. 3 In intact mice and in mice implanted with 10 mg of CORT, haloperidol treatment significantly increased prepulse inhibition (average values from 38 - 42 to 52%). Similar results were observed when testing the mice for amphetamine-induced locomotor hyperactivity (5 mg kg(-1)). In contrast, there was no significant effect of haloperidol in mice implanted either with cholesterol or 2 or 50 mg of CORT. 4 These results in behavioural animal models of schizophrenia suggest an important role of the stress hormone CORT in modulating dopaminergic activity in this illness.

Detour behavior changes associated with prenatal morphine exposure in 11-day-old chicks

The central nervous system exhibits remarkable plasticity in early life. Prenatal morphine exposure may induce adverse behavioral effects on the neonate and the developing offspring. In the present study, we investigated the effect of prenatal morphine exposure (daily from embryonic days 12-16, 20 mg/kg) on 11-day-old chicks using two forms of spatial paradigms: one trial detour behavior task in which animals must bypass an obstacle to reach the desired goal without any training and detour learning task which required several trials of training to reach the detour criterion. The results showed that, on the condition that chicks could successfully detour in the first trial, morphine exposed chicks exhibited longer detour latency to finish the task, coupled by a preference for turning right versus turning left. In contrast, no significant difference in learning and memory was found in detour learning task between morphine exposed chicks and saline chicks. These findings suggest specific behavioral changes associated with prenatal exposure to opioids during mid to late gestation, also raise attention to the possible health hazard from pregnancy drug use in everyday life. (C) 2010 ISDN. Published by Elsevier Ltd. All rights reserved.

The survey of sexual maturity in Mugil cephalus so measuring sex hormones and histologic studies

In this study the process of female gray mullet brooders was carried out by using histological study and masurment of sex steroids. Results of histological studies showed that oocyte of gray mullet brooders in Gomishan Rearing Center conditions of develop to the end of yolk globule stage. The results were observed with oocyte in chromatin nucleolar stage (first stage) with means of diameter of 20 p m, in August, perinucleolar stage (second stage) in September with mean diameter of 87 p m, yolk vesicle stage (third stage) in October with mean diameter 200 p m and yolk granules stage (forth stage) from October to November with average diameter of 180 — 650 p m. For the reason of stopping oocyte develop at the end of fourth stage, hormonal induction to final oocyte maturation and ovulation was used. For this purpose, carp pituitary , HCG and LRH-A2 with different combinations were used in two stages, second injection was used 24 hours after first injection. 15 females brooders were divided in 5 groups, different hormonal combinations were injected to four groups and to fifth group as control, only saline, was injected. The process of female brooder rippening in hormonal induction was studied via masurment of sex steroids including 17 a - hydroxy progestrone, estradio1-17)6 and testosterone. Blood samples were collected from caudal vein during first injection, 24, 30 and 48 hours after the first injection. At the same time, for distinguishing histological changes the sample has been attained from the gonads Sex stroid fluctuation patterns in different brooder groups that injected hormon were similar, however hormonal composition had similar effects. All brooder that their oocyte in the beginning of hormonal injection were At the end of fourth stage with oocyte diameter average of 600 p m received to final maturation and ovulation. The brooder that its oocytes were At the begining or mid-fourth stage did not show ovulation but hormonal induction caused oocyte develop at the beginning of fifth stage. Study of 17-hydroxy progestrone fluctuation showed that the maximum level of this steroid (0.347 ng/ml) measured 30 hours after the first injection and was significantly higher (p< 0.05) than those of control group. So, 17-hydroxy progestrone is probably precursor of maturation inducing steroid (MIS). However the maximum level of that observed was coincident with germinal vesicle breakdown, oil droplets coalescence and dissolution of yolk granuls The maximum levels of esteradiol— 17/0 and testosterone (3.778 and 16.801ng/ml,respectively) in spawned brooders,were observed 24 hours after the first injection. levels of those steroids were significantly higher (p<0.05) than control group. Maximum level of sex steroids in the brooders that did not spawn to the end of treatment was observed with more delay than those in spawned brooders. Therefor maximum level of 17a-hydroxy progestrone (0.264 ng/ml) in those brooders observed in fourth sampling time and the maximum levels of estradio1-17a and testosterone (2.944 and 18.993 ng/ml, respectivly)observed in third sampling time that was significantly higher (p<0.05) than those of control group. For the study of stress effect on brooders during the hormonal induction, level of cortisol was measured in every sampling time. level of cortisol had high fluctuation that showed handling level and stress effect on brooders. However maximum level of cortisol in majority of brooders was dominant in third sampling time that was coincident with final maturation.

Impact of seafarming: fish farms vs. mussel farms

The article presents comparative impacts of fish and mussel seafarms. Specifically, it tackles the impacts of the two farms on the following: solid waste production, water flow and sedimentation, effect on native bottom fauna, effect on wild fish populations, the spread of toxic chemicals and drugs, and multi-use conflicts.

On the ecology and explorations of the fisheries of an East African rift valley lake, Part 1: On the bionomics and population structure of Tilapia nilotica Linnaeus 1757 in Lake Baringo, Kenya

An ecological survey of the fisheries of Lake Baringo, Kenya was carried out between August, 1972 and August, 1973. The bionomics and population structure of T. nilotica is described. Sampling was done with multifilament gillnets of graded mesh sizes from 51 mm to 178 mm in approximately 12.5 mm increments. The Lake was divided into three sampling and ecologically different zones - the south, central and north zones. The size range of T. nilotica of both sexes caught was between 5 and 27 cm (mode 16 cm) with a mean length of 16.07 cm. For all the collections, males dominated (55.3%) and a higher proportion of males were caught in January, August and November. The smallest mature male and female was 9 and 10 cm respectively. Males grow faster and mature at larger sizes than females. 50% of all males and females mature at 17.4 and 16:4 cm respectively. The periods of intense spawning were between August and October and January to April. The Tilapia were feeding best in central and north zones and the feeding intensity was reduced in January. Two endoparasites Contracaecum sp. and Clinostomum sp. were isolated from the Tilapia. The "condition" of the fish was better in the north than in the other two zones.

Improving effects of huperzine A on spatial working memory in aged monkeys and young adult monkeys with experimental cognitive impairment

Our previous studies demonstrated that huperzine A, a reversible and selective acetylcholinesterase inhibitor, exerts beneficial effects on memory deficits in various rodent models of amnesia. To extend the antiamnesic action of huperzine A to nonhuman primates, huperzine A was evaluated for its ability to reverse the deficits in spatial memory produced by scopolamine in young adult monkeys or those that are naturally occurring in aged monkeys using a delayed-response task. Scopolamine, a muscarinic receptor antagonist, dose dependently impaired performance with the highest dose (0.03 mg/kg, i.m.) producing a significant reduction in choice accuracy in young adult monkeys. The delayed performance changed from an average of 26.8/30 trials correct on saline control to an average of 20.2/30 trials correct after scopolamine administration. Huperzine A (0.01-0.1 mg/kg, i.m.) significantly reversed deficits induced by scopolamine in young adult monkeys on a delayed-response task; performance after an optimal dose (0.1 mg/kg) averaged 25.0/30 correct. In four aged monkeys, huperzine A (0.001-0.01 mg/kg, i.m.) significantly increased choice accuracy from 20.5/30 on saline control to 25.2/30 at the optimal dose (0.001 mg/kg for two monkeys and 0.01 mg/kg for the other two monkeys). The beneficial effects of huperzine A on delayed-response performance were long lasting; monkeys remained improved for about 24 h after a single injection of huperzine A. This study extended the findings that huperzine A improves the mnemonic performance requiring working memory in monkeys, and suggests that huperzine A may be a promising agent for clinical therapy of cognitive impairments in patients with Alzheimer's disease.

On the transition from finite-volume negatively buoyant releases to continuous fountains

An experimental investigation to identify the source conditions that distinguish finite-volume negatively buoyant fluid projectile behaviour from fountain behaviour in quiescent environments of uniform density is described. Finite-volume releases are governed by their source Froude number Fr D and the aspect ratio L/D of the release, where L denotes the length of the column of fluid dispensed vertically from the nozzle of diameter D. We establish the influence of L/D on the peak rise heights of a release formed by dispensing saline solution into fresh water for 0

Density stratified environments: The double-tank method

We present an alternative method of producing density stratifications in the laboratory based on the 'double-tank' method proposed by Oster (Sci Am 213:70-76, 1965). We refer to Oster's method as the 'forced-drain' approach, as the volume flow rates between connecting tanks are controlled by mechanical pumps. We first determine the range of density profiles that may be established with the forced-drain approach other than the linear stratification predicted by Oster. The dimensionless density stratification is expressed analytically as a function of three ratios: the volume flow rate ratio n, the ratio of the initial liquid volumes λ and the ratio of the initial densities ψ. We then propose a method which does not require pumps to control the volume flow rates but instead allows the connecting tanks to drain freely under gravity. This is referred to as the 'free-drain' approach. We derive an expression for the density stratification produced and compare our predictions with saline stratifications established in the laboratory using the 'free-drain' extension of Oster's method. To assist in the practical application of our results we plot the region of parameter space that yield concave/convex or linear density profiles for both forced-drain and free-drain approaches. The free-drain approach allows the experimentalist to produce a broad range of density profiles by varying the initial liquid depths, cross-sectional and drain opening areas of the tanks. One advantage over the original Oster approach is that density profiles with an inflexion point can now be established. © 2008 Springer-Verlag.

The rhythm of fountains: The length and time scales of rise height fluctuations at low and high Froude numbers

The magnitude and frequency of vertical fluctuations of the top of an axisymmetric miscible Boussinesq fountain forms the focus of this work. We present measurements of these quantities for saline-aqueous fountains in uniform quiescent surroundings. Our results span source Froude numbers 0.3 ≤ Fr 0 ≤ 40 and, thereby, encompass very weak, weak, intermediate and forced classes of fountain. We identify distinct scalings, based on known quantities at the fountain source, for the frequency of fountain height fluctuations which collapse our data within bands of Fr0. Notably, our scalings reveal that the (dimensionless) frequency takes a constant value within each band. These results highlight characteristic time scales for the fluctuations which we decompose into a single, physically apparent, length scale and velocity scale within each band. Moreover, within one particular band, spanning source Froude numbers towards the lower end of the full range considered, we identify unexpectedly long-period fluctuations indicating a near balance of inertia and (opposing) buoyancy at the source. Our analysis identifies four distinct classes of fluctuation behaviour (four bands of Fr 0) and this classification matches well with existing classifications of fountains based on rise heights. As such, we show that an analysis of the behaviour of the fountain top alone, rather than the entire fountain, provides an alternative approach to classifying fountains. The similarity of classifications based on the two different methods confirms that the boundaries between classes mark tangible changes in the physics of fountains. For high Fr0 we show that the dominant fluctuations occur at the scale of the largest eddies which can be contained within the fountain near its top. Extending this, we develop a Strouhal number, Strtop, based on experimental measures of the fountain top, defined such that Strtop = 1 would suggest the dominant fluctuations are caused by a continual cycle of eddies forming and collapsing at this largest physical scale. For high- Fr 0 fountains we find Strtop ≈ 0. 9. © 2013 Cambridge University Press.

Oxidative stress response after prolonged exposure of domestic rabbit to a lower dosage of extracted microcystins

Oxidative stress response after prolonged exposure to a low dose of microcystins (MCs) was studied in liver, kidney and brain of domestic rabbits. Rabbits were treated with extracted MCs (mainly MC-LR and MC-RR) at a dose of 2 MC-LReq. mu g/kg body weight or saline solution every 24 h for 7 or 14 days. During the exposure of MCs, increase of lipid peroxidation (LPO) levels were detected in all the organs studied, while antioxidant enzymes responded differently among different organs. The enzyme activities Of Superoxide dismutase (SOD). catalase (CAT) and glutathione reductase (GR) in liver decreased in the MCs treated animals. In brain, there were obvious changes in glutathione peroxidase (GPx) and GR, while only CAT was obviously influenced in kidney. Therefore, daily exposure at a lower dosage of MCs, which mimicked a natural route of MCs. could also induce obvious oxidative stress in diverse organs of domestic rabbits. The oxidative stress induced by MCs in brain was as serious as in liver and kidney, suggesting that brain may also be a target of MCs in mammals. And it seems that animals may have more time to metabolize the toxins or to form an adaptive response to reduce the adverse effects when exposed to the low dose of MCs. (C) 2008 Elsevier B.V. All rights reserved.

Calibration of alkenone unsaturation index with growth temperature for a lacustrine species, Chrysotila lamellosa (Haptophyceae)

Although long chain alkenones (LCKs) occur widely in lacustrine sediments, their origin is not clear. Here, we report a lacustrine source, the non-calcifying species Chrysotila lamellosa Anand (Haptophyceae), collected and isolated from an inland saline water body, Lake Xiarinur (Inner Mongolia, China). Its alketione pattern is similar to those of coastal marine strains of C lamellosa,but the relationship between U-37(K') index and culture temperature for the lacustrine species is quite different from that of the coastal species. A significant feature of the alkenones in this strain of C lamellosa is a lack of C-38 methyl alkenones, which might be used to distinguish the species from the marine haptophyte species Emiliania huxleyi and Gephyrocapsa oceanica. The higher C-38 tetraunsaturated compound abundance might be another important feature for distinguishing the C lamellosa alkenone producer from the coastal species Isochrysis galbana. This alkenone distribution pattern has been detected in many lakes, which suggests that C lamellosa or a closely related species might be a very common alkenone precursor in lacustrine systems. We examined U-37(K') and U-37(K) values for C lamellosa as a function of culture temperature in a batch culture experiment. The calibration for U-37(K') vs. culture temperature (T) was U-37(K') = 0.0011 x T-2 - 0.0157 x T + 0.1057(n = 14, r(2) = 0.99) from 10 degrees C to 22 degrees C or U-37(K') = 0.0257 x T - 0.2608(n = 9, r(2) = 0.97) from 14 degrees C to 22 degrees C. U-37(K) vs. culture temperature was U-37(K) = 0 0377 x T - 0.5992(n = 14, r(2) = 0.98) from 10 degrees C to 22 degrees C. Our experiments show that the alkenone unsaturation index (U-37(K')) is strongly controlled by culture temperature and can be used for palaeoclimate reconstruction. (C) 2007 Elsevier Ltd. All rights reserved.

Effects of salt stress on carbohydrate metabolism in desert soil alga Microcoleus vaginatus Gom.

The effects of salt stress on carbohydrate metabolism in Microcoleus vaginatus Gom., a cyanobacterium isolated from desert algal crusts, were investigated in the present study. Extracellular total carbohydrates and exopolysaccharides (EPS) in the culture medium produced by M. vaginatus increased significantly during the growth phase and reached a maximum during the stationary phase. The production of extracellular carbohydrates also significantly increased under higher salt concentrations, which was attributed to an increase in low molecular weight carbohydrates. In the presence of NaCl, the production of cellular total carbohydrates decreased and photosynthetic activity was impaired, whereas cellular reducing sugars, water-soluble sugars and sucrose content and sucrose phosphate synthase activity increased, reaching a maximum in the presence of 200 mmol/L NaCl. These parameters were restored to original levels when the algae were transferred to a non-saline medium. Sodium and K+ concentrations of stressed cells decreased significantly and H+-ATPase activity increased after the addition of exogenous sucrose or EPS. The results suggest that EPS and sucrose are synthesized to maintain the cellular osmotic equilibrium between the intra- and extracellular environment, thus protecting algal cells from osmotic damage, which was attributed to the selective exclusion of cellular Na+ and K+ by H+-ATPase.

Effects of anti-bursin monoclonal antibody on immunosuppression in the duck (Cherry Valley duck)

To study the immunologic function of bursin, we analyzed the effects of anti-bursin monoclonal antibody (mAb) on the immunosuppression in ducks (Cherry Valley duck) by injecting various doses of the anti-bursin mAb into 13-d duck embryos. After hatch, cell-mediated immune activity and humoral responses were studied using lymphocyte proliferation test, tube agglutination test, and indirect enzyme-linked immuno-sorbent assay to detect anti-Escherichia coli antibodies and antibodies to Riemerella anatipester, respectively. Simultaneously, relative weights (BW-adjusted) of bursa of Fabricius (BF), spleen, and thymus were determined. Additionally, the morphology of BF, spleen, and thymus was examined at various ages using conventional histology. Follicle morphology of BF was analyzed by image analysis. The results indicated that anti-bursin mAb markedly decreased duck lymphocyte proliferation, the antibody-producing ability to bacteria, as well as the relative BF weight. Moreover, the anti-bursin mAb hindered the development of BF follicles.