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B. Rydqvist - One of the best experts on this subject based on the ideXlab platform.
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Action Potential and Sodium Current in the Slowly and Rapidly Adapting Stretch Receptor Neurons of the Crayfish (astacus astacus)
Journal of Neurophysiology, 1998Co-Authors: Nuhan Purali, B. RydqvistAbstract:Purali, Nuhan and Bo Rydqvist. Action potential and sodium current in the slowly and rapidly adapting stretch receptor neurons of the crayfish (astacus astacus). J. Neurophysiol. 80: 2121–2132, 1998. Action potentials (APs) and sodium current from the slowly and the rapidly adapting stretch receptor neurons in the crayfish (astacus astacus) were recorded with a two microelectrode voltage- and current-clamp technique. In the rapidly adapting neuron the APs had a duration of 3.2 ± 0.2 ms (means ± SE) and an amplitude of 55.2 ± 1.5 mV. In the slowly adapting receptor neuron APs had a duration of 4.1 ± 0.2 ms and an amplitude 79.9 ± 2.0 mV. APs in the rapidly adapting neuron had a larger amplitude if they were recorded from the axon. In the rapidly adapting neuron adaptation of the impulse response was prolonged by hyperpolarization or by exposure to scorpion venom. Also, sinusoidal current stimulation added to the current steps prevented impulse adaptation. Block of the potassium currents in the slowly adapt...
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Action Potential and Sodium Current in the Slowly and Rapidly Adapting Stretch Receptor Neurons of the Crayfish (astacus astacus)
Journal of neurophysiology, 1998Co-Authors: Nuhan Purali, B. RydqvistAbstract:Purali, Nuhan and Bo Rydqvist. Action potential and sodium current in the slowly and rapidly adapting stretch receptor neurons of the crayfish (astacus astacus). J. Neurophysiol. 80: 2121–2132, 199...
Nuhan Purali - One of the best experts on this subject based on the ideXlab platform.
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Action Potential and Sodium Current in the Slowly and Rapidly Adapting Stretch Receptor Neurons of the Crayfish (astacus astacus)
Journal of Neurophysiology, 1998Co-Authors: Nuhan Purali, B. RydqvistAbstract:Purali, Nuhan and Bo Rydqvist. Action potential and sodium current in the slowly and rapidly adapting stretch receptor neurons of the crayfish (astacus astacus). J. Neurophysiol. 80: 2121–2132, 1998. Action potentials (APs) and sodium current from the slowly and the rapidly adapting stretch receptor neurons in the crayfish (astacus astacus) were recorded with a two microelectrode voltage- and current-clamp technique. In the rapidly adapting neuron the APs had a duration of 3.2 ± 0.2 ms (means ± SE) and an amplitude of 55.2 ± 1.5 mV. In the slowly adapting receptor neuron APs had a duration of 4.1 ± 0.2 ms and an amplitude 79.9 ± 2.0 mV. APs in the rapidly adapting neuron had a larger amplitude if they were recorded from the axon. In the rapidly adapting neuron adaptation of the impulse response was prolonged by hyperpolarization or by exposure to scorpion venom. Also, sinusoidal current stimulation added to the current steps prevented impulse adaptation. Block of the potassium currents in the slowly adapt...
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Action Potential and Sodium Current in the Slowly and Rapidly Adapting Stretch Receptor Neurons of the Crayfish (astacus astacus)
Journal of neurophysiology, 1998Co-Authors: Nuhan Purali, B. RydqvistAbstract:Purali, Nuhan and Bo Rydqvist. Action potential and sodium current in the slowly and rapidly adapting stretch receptor neurons of the crayfish (astacus astacus). J. Neurophysiol. 80: 2121–2132, 199...
Rolf Gydemo - One of the best experts on this subject based on the ideXlab platform.
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Signal crayfish, Pacifastacus leniusculus, as a vector for Psorospermium haeckeli to noble crayfish, astacus astacus.
Aquaculture, 1996Co-Authors: Rolf GydemoAbstract:Abstract As part of investigations of the ecological impact and transmission of the crayfish parasite Psorospermium haeckeli , a laboratory experiment was performed where noble crayfish, astacus astacus , and signal crayfish, Pacifastacus leniusculus , from populations in which P. haeckeli had not been detected, were fed with each other in all combinations. Noble crayfish fed noble crayfish did not acquire P. haeckeli during the experimental period of 10 months, while noble crayfish fed signal crayfish did. Signal crayfish fed noble crayfish showed a lower frequency of definitive positive infestation than signal crayfish fed signal crayfish. The results support the theory that Psorospermium haeckeli has been introduced to the Baltic island of Gotland with signal crayfish, and that signal crayfish, when not infected with the crayfish plague fungus Aphanomyces astaci , is more successful in suppressing the parasite. The investigations also showed that the technique of digesting soft tissues might be an inadequate method of observing P. haeckeli in signal crayfish.
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Predation on larvae of the noble crayfish, astacus astacus L.
Aquaculture, 1990Co-Authors: Rolf Gydemo, Lars Westin, Anders NisslingAbstract:Abstract The predation by dragonfly larvae ( Aeschna grandis ) and adult female crayfish on second-stage young of the noble crayfish, astacus astacus , was studied in aquarium experiments. Combinations of crayfish young with and without adult female crayfish, with and without shelter were made in 4×4 set-ups with dragonfly larvae and 4×2 without. Dragonfly larvae and adult female crayfish rapidly reduced the number of surviving crayfish larvae. When neither adult crayfish females nor dragonfly larvae were present and crayfish juveniles also had access to shelter, the survival rate was high.
Liisa A. Kivivuori - One of the best experts on this subject based on the ideXlab platform.
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Fluidity of Neuronal Membranes of Crayfish (astacus astacus L.) Acclimated to 5°C and 20°C
Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology, 1998Co-Authors: Sirpa M. Lehti-koivunen, Liisa A. KivivuoriAbstract:Abstract The fluidity of microsomal membranes from nerve cords of eurythermal freshwater crayfish astacus astacus acclimated to 5°C or to 20°C was measured by steady-state fluorescence polarization. Membrane fluidity was measured at 4–24°C during a cyclic temperature change (0.2°C/min) using 1,6-diphenyl-1,3,5-hexatriene (DPH) or 1-(4-trimethylammoniumphenyl)-6-phenyl-1,3,5-hexatriene (TMA-DPH) molecule as probes. The fluidity of neuronal membranes depended on temperature but not on the direction of temperature change. Thermal dependence of fluidity was higher with DPH than with TMA-DPH. Neuronal microsomal membranes of cold-acclimated crayfish were more fluid than those of warm-acclimated animals. Except at the lowest experimental temperatures, in both microsomal and plasma membranes, the TMA-DPH polarization values were higher than the DPH polarization values, indicating the anchorage of TMA-DPH to the more rigid hydrophilic surface of the bilayer at these temperatures in both membranes. Neuronal plasma membranes were more rigid than microsomal membranes measured with DPH. With TMA-DPH plasma membranes were more fluid than microsomal membranes.
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Temperature selection behaviour of cold- and warm-acclimated crayfish [astacus astacus (L.)]
Journal of Thermal Biology, 1994Co-Authors: Liisa A. KivivuoriAbstract:1. 1.|Using a toroidal gradient apparatus with a thermal water gradient from 4 to 18°C (a cool gradient), the mean temperature on the anterior carapace surface (Ts) of the freely moving crayfish during 1 h period after 3–4 h gradient exposure was 11.9°C in 5°C-acclimated animals and 16.1°C in 20°C-acclimated ones. With a gradient extending from 10 to 25°C (a temperate gradient), the Ts was 15.3 and 18.0°C respectively. 2. 2.|In the cool gradient, 5°C-acclimated crayfish wandered evenly, while 20°C-acclimated ones avoided temperatures below 10.3°C. In the temperate gradient, the means of the upper avoidance temperatures were 20.4 and 23.0°C for the 5°C- and 20°C-acclimated animals respectively. 3. 3.|Temperature acclimation of crayfish astacus astacus changed their temperature selection and avoidance behaviour.
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Effect of temperature acclimation in the crayfish astacus astacus L. on the locomotor activity during a cyclic temperature change
Journal of Thermal Biology, 1994Co-Authors: Sirpa M. Lehti-koivunen, Liisa A. KivivuoriAbstract:Abstract 1. 1.|The thermal dependence of the locomotor activity of 5°C- and 20°C-acclimated crayfish (astacus astacus L.) was studied using a cyclic temperature change (0.3°C/min) at 4-23-4°C. 2. 2.|The thermal dependence of the locomotor activity rate of the 5°C-acclimated crayfish showed hysteresis between 5 and 14°C; activity being higher during cooling than during warming. In the 20°C-acclimated animals, no hysteresis in the thermal dependence of locomotor activity was observed. 3. 3.|In both acclimation groups the locomotor activity rate was inversely related to temperature between 7 and 23°C, irrespective of the direction of the temperature change. 4. 4.|During warming from 9 to 19°C, the 20°C-acclimated crayfish were more active than the 5°C-acclimated ones. 5. 5.|At the lowest temperatures (4–6°C), inactivity related to chill coma was observed in the warm-acclimated crayfish.
Kenneth Söderhäll - One of the best experts on this subject based on the ideXlab platform.
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The origin of two crayfish plague (Aphanomyces astaci) epizootics in Finland on noble crayfish, astacus astacus
Annales Zoologici Fennici, 1998Co-Authors: Pia Vennerström, Kenneth Söderhäll, Lage CereniusAbstract:A fungus identified as Aphanomyces astaci was isolated from two crayfish plague epizootics among noble crayfish, astacus astacus, in Central Finland. The isolated fungal strains from Vaikkojoki, Ka ...
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β-1,3-glucan-binding Proteins From Plasma of the Fresh-water Crayfishes astacus astacus and Procambarus Clarkii
Journal of Crustacean Biology, 1993Co-Authors: Bernard Duvic, Kenneth SöderhällAbstract:ABSTRACT Two fresh-water crayfishes, astacus astacus and Procambarus clarkii, and a marine crab, Carcinus maenas, were examined for the presence of β-1,3-glucan-binding proteins in their plasma. By the use of a monospecific rabbit polyclonal antiserum to the β-1,3-glucan-binding protein of Pacifastacus leniusculus, 2 proteins from the plasma of astacus astacus with molecular masses of about 105 kDa and 95 kDa as well as a 100-kDa protein in the plasma of Procambarus clarkii could be detected. No protein in plasma of Carcinus maenas cross-reacted with the anti-Pacifastacus leniusculus β-1,3-glucan-binding protein antibodies. The cross-reactive proteins from plasma of astacus astacus were purified by immuno-affinity chromatography. The isolated proteins were homogenous as judged by electrophoresis on SDS-PAGE. Isoelectric focusing of the purified proteins gave pIs of about 6.1 and 6.4. The purified proteins from the plasma of astacus astacus enhanced the activity of a hemocyte lysate supernatant-derived phenoloxidase of Pacifastacus leniusculus as did the β-1,3-glucanbinding protein of Pacifastacus leniusculus.
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Beta-1,3-glucan binding proteins from plasma of the fresh-water crayfishes astacus astacus and Procambarus clarkii
Journal of Crustacean Biology, 1993Co-Authors: Bernard Duvic, Kenneth SöderhällAbstract:Two fresh-water crayfishes, astacus astacus and Procambarus clarkii, and a marine crab, Carcinus maenas, were examined for the presence of beta-1,3-glucan-binding proteins in their plasma. By the use of a monospecific rabbit polyclonal antiserum to the beta-1,3-glucan-binding protein of Pacifastacus leniusculus, 2 proteins from the plasma of astacus astacus with molecular masses of about 105 kDa and 95 kDa as well as a 100-kDa protein in the plasma of Procambarus clarkii could be detected. No protein in plasma of Carcinus maenas cross-reacted with the anti-Pacifastacus leniusculus beta-1,3-glucan-binding protein antibodies. The cross-reactive proteins from plasma of astacus astacus were purified by immuno-affinity chromatography. The isolated proteins were homogenous as judged by electrophoresis on SDS-PAGE. Isoelectric focusing of the purified proteins gave pIs of about 6.1 and 6.4. The purified proteins from the plasma of astacus astacus enhanced the activity of a hemocyte lysate supernatant-derived phenoloxidase of Pacifastacus leniusculus as did the beta-1,3-glucan-binding protein of Pacifastacus leniusculus.
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Isolation of Trichosporon beigelii from the freshwater crayfish astacus astacus
Aquaculture, 1993Co-Authors: Kenneth Söderhäll, Jari Rantamäki, Ovidiu ConstantinescuAbstract:Abstract A new fungal pathogen, Trichosporon beigelii , for the freshwater crayfish, astacus astacus , was isolated from the cuticle of several crayfish specimens which had been held in aquaria containing lake water supplemented with MgCl 2 as part of an unrelated experiment involving another fungus, Aphanomyces astaci . The presence of T. beigelii hyphae in the cuticle of crayfish consistently induced a strong melanotic response relative to that induced by the hyphae of the crayfish plague fungus, A. astaci , which usually does not induce any such response. T. beigelii is known to be capable of parasitizing a number of different vertebrates. It therefore seems likely that crayfish may act as a vector for this animal pathogen and that this fungus could become a problem in crayfish culture.
