Serotonin, nitric oxide (NO) and histamine are neuromodulators used in molluscan nervous systems. We have found that each of them depolarizes and increases the excitability of the serotonergic feeding neural circuit modulator neuron, MCC, of Aplysia, but each induces different changes in background ionic currents and uses a different second messenger. Stimulation of neuron C2 in the cerebral ganglion induces a vsEPSP in MCC using NO and histamine. When these neurons are isolated in culture they form synapses that mediate the vsEPSP. The ionic currents induced by these neuromodulators were investigated in isolated cultured MCCs. Histamine reduced a background outward current between -70 and -30 mV that was blocked by cobalt treatment, indicating that it is a calcium activated potassium current. Serotonin reduced a background outward current from -65 mV to -30 mV and enhanced a potassium inward current more negative than -70 mV that was blocked by cesium and barium. This response was mimicked by 8-Br-cAMP. NO donors reduced a cobalt insensitive background outward current between -70 and -30 mV. This response was mimicked by 8-Br-cGMP. These responses show that MCC can produce complex time and state-dependent activity during its modulation of the feeding neural circuit.
Authors:T. Bačić, Lj. Krstin, J. Roša, and Ž. Popović
Concentration of carbon (C), oxygen (O), nitrogen (N), magnesium (Mg), aluminium (Al), silicon (Si), phosphorus (P), mercury (Hg), sulphur (S), lead (Pb), chlorine (Cl), potassium (K), cadmium (Cd), calcium (Ca), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), copper (Cu) and zinc (Zn), in the form of weight percentage, in the needles of different age classes, current and previous year one, of two sites, Risnjak National Park and Donja Dobra (control), were measured by X-ray microanalysis (EDAX) in the Scanning Electron Microscope in silver fir trees (Abies alba Mill.). The analysis suggests that accumulation of elements, in both years, particularly that of heavy metals, appeared in polluted site, like Risnjak, in the higher amount, whereas in non polluted, like Donja Dobra, in the lower amount. Moreover, it seems likely that elements at the first sites were accumulated and contaminated in very young current year needles, while in non polluted in somewhat older, the previous year ones.
Biochemical and elemental compositions, ascorbic acid, vitamin A, some levels of toxicants and anti-nutritional substances of the leaflets of a tropic fern species, Nephrolepis furcans were investigated. This is to ascertain its nutrient and toxicity levels; potentiality of its incorporation into livestock feeds; for feeding domestic animals and cultivation for ornamental purposes. Proximate analysis showed the presence of 0.87% protein, 85% moisture, 0.24% fat, 2.10% ash, 3.26% crude fibre, 8.53% carbohydrate, 15 g / 100 g dry matter, 18.18 mg /100 g ascorbic acid and 0.11% vitamin A. Mineral elements present include chromium 12.00±0.0004 (mg/100 g), iron 2,620.25±0.0036 (mg/100 g), manganese 6.00±0.0002 (mg/100 g), cobalt 244.50±0.002 (mg/100 g), cadmium 59.00±0.0002 (mg/100 g), lead 62.50±0.0015 (mg/100 g), magnesium 1,426.50±0.0002 (mg/100 g), calcium 13,041.00± 0.0172 (mg/100 g), mercury 431.75±0.0003 (mg/100 g), nickel 1,070.25±0.0005 (mg/100 g), potassium 2,515.00± 0.0027 (mg/100 g), sodium 803.00±0.0007 (mg/100 g), selenium 920.75±0.021 (mg/100 g), arsenium 1923.50±0.0030 (mg/100 g). Copper and zinc were not detected. Toxic components were oxalate 0.216 mg / 100 g and hydrogen cyanide 0.040 mg/100 g. Phytochemical screening showed the presence of tannin, flavonoids, cardiac-glycoside, reducing sugar, carbohydrate, but saponin, alkaloids and phlobatannins were not detected. Anti-nutritional substances detected are lignin, acid detergent fibre, neutral detergent fibre and hemicellulose. The toxic and anti-nutritional components are very low and are not likely to pose any serious health hazard to the ruminants eating this plant.
Authors:F. Oloyede, F. Oloyede, T. Saliu, and A. Ogunwole
Extracts from some fern species have been found to be useful in fortifying livestock and fish feeds to enhance production especially in peasant communities. The chemical composition of
has not been documented in Nigeria. This study was thus designed to determine its suitability for use in fortifying fish feed by analysing the nutrient and anti-nutrient contents of its dimorphic fronds separately. One kg of sterile and fertile fronds of
were collected, washed using distilled water and oven dried at 40 °C for about 96 hours. The dried samples were milled and analysed for proximate minerals, cyanide and oxalate analyses in triplicates. Results of the nutrient and anti-nutrient analyses show that both the sterile and the fertile fronds of
can be used in aquaculture. The crude protein (4.22–5.28 g/100 g), moisture (87–91.00 g/100 g), carbohydrate (3.12–7.40 g/100 g), magnesium (23.55–194.65 mg/100 g), calcium (0.03 mg/100 g), potassium (0.17 mg/100 g), sodium (0.17 mg/100 g), silver (50.0 mg/100 g), cobalt (3.75–4.45 mg/100 g), lead (53.5–172.5 mg/100 g), copper (60.45–61.0 mg/100 g), manganese (15.65 mg/100 g), arsenium (50 mg/100 g), cadmium (3.75–4.50 mg/100 g), iron (430.00–537.45 mg/100 g) and selenium (106.83–195.45 mg/100 g) contents are considerably high. The anti-nutritional oxalate (0.86–1.38 mg/100 g) and cyanide (0.88–1.16 mg/100 g) are low and fall within the safe and acceptable limits as recommended by the World Health Organisation. Thus, extract from these fronds can be incorporated into livestocks and fish meals.
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J. Biol. Chem. 274
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Cobalt filling of sensory projections from internal and external
Authors:G. Molnár, J. Győri, J. Salánki, and Katalin S.-Rózsa
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Blocking effect of cobalt and related ions
and structural characterization of silver(I), aluminium(III) and cobalt(II) complexes with 4-isopropyltropolone (hinokitiol) showing noteworthy biological activities. Action of silver(I)-oxygen bonding complexes on the antimicrobial activities. J