Garden Snail Helix Pomatia Research Articles

Using Higuchi’s fractal dimension in fine analysis of the effects of 2.7 mT and 10 mT static magnetic fields on the complex bursting activity of the snail BR neuron

The components of complex bioelectrical activity ? action potential (AP), interspike interval (ISI) and the quiet interburst interval (IBI), along with the effects of 2.7 mT and 10 mT static magnetic fields, were identified and examined in the spontaneously active Br neuron of the subesophageal ganglion complex of the garden snail Helix pomatia by fractal analysis using Higuchi?s fractal dimension (FD). The normalized mean of the empirical FD distributions of bursting activity of the Br neuron were formed under different experimental conditions: before (Control), during (MF), and after exposure to the static magnetic field (AMF). Using the fractal analysis method for the first time, a separation of the AP, ISI and IBI components was successfully achieved. Our results show that fractal analysis with deconvolution of the normalized mean of the empirical FD distributions into Gaussian functions is a useful tool for revealing the effects of magnetic fields on the complexity of neuronal bioelectric activity and its AP, ISI and IBI components.

Changes in the expression and current of the Na+/K+ pump in the snail nervous system after exposure to static magnetic field

Compelling evidence supports the use of a moderate static magnetic field (SMF) for therapeutic purposes. In order to provide insight into the mechanisms underlying SMF treatment, it is essential to examine the cellular responses elicited by therapeutically applied SMF, especially in the nervous system. The Na(+)/K(+) pump, by creating and maintaining the gradient of Na(+) and K(+) ions across the plasma membrane, regulates the physiological properties of neurons. In this study, we examined the expression of the Na(+)/K(+) pump in the isolated brain-subesophageal ganglion complex of the garden snail Helix pomatia, along with the immunoreactivity and current of the Na(+)/K(+) pump in isolated snail neurons after 15 min exposure to a moderate (10 mT) SMF. Western blot and immunofluorescence analysis revealed that 10 mT SMF did not significantly change the expression of the Na(+)/K(+) pump α-subunit in the snail brain and the neuronal cell body. However, our immunofluorescence data showed that SMF treatment induced a significant increase in the Na(+)/K(+) pump α-subunit expression in the neuronal plasma membrane area. This change in Na(+)/K(+) pump expression was reflected in pump activity as demonstrated by the pump current measurements. Whole-cell patch-clamp recordings from isolated snail neurons revealed that Na(+)/K(+) pump current density was significantly increased after the 10 mT SMF treatment. The SMF-induced increase was different in the two groups of control snail neurons, as defined by the pump current level. The results obtained could represent a physiologically important response of neurons to 10 mT SMF comparable in strength to therapeutic applications.

Involvement of Na+/K+pump in fine modulation of bursting activity of the snail Br neuron by 10 mT static magnetic field

The spontaneously active Br neuron from the brain-subesophageal ganglion complex of the garden snail Helix pomatia rhythmically generates regular bursts of action potentials with quiescent intervals accompanied by slow oscillations of membrane potential. We examined the involvement of the Na(+)/K(+) pump in modulating its bursting activity by applying a static magnetic field. Whole snail brains and Br neuron were exposed to the 10-mT static magnetic field for 15min. Biochemical data showed that Na(+)/K(+)-ATPase activity increased almost twofold after exposure of snail brains to the static magnetic field. Similarly, (31)P NMR data revealed a trend of increasing ATP consumption and increase in intracellular pH mediated by the Na(+)/H(+) exchanger in snail brains exposed to the static magnetic field. Importantly, current clamp recordings from the Br neuron confirmed the increase in activity of the Na(+)/K(+) pump after exposure to the static magnetic field, as the magnitude of ouabain's effect measured on the membrane resting potential, action potential, and interspike interval duration was higher in neurons exposed to the magnetic field. Metabolic pathways through which the magnetic field influenced the Na(+)/K(+) pump could involve phosphorylation and dephosphorylation, as blocking these processes abolished the effect of the static magnetic field.

Effect of alternating the magnetic field on phosphate metabolism in the nervous system of Helix pomatia.

The effect of extremely low frequency magnetic fields (50 Hz, 0.5 mT) - ELF-MF, on phosphate metabolism has been studied in the isolated ganglions of the garden snail Helix pomatia, after 7 and 16 days of snail exposure to ELF-MF. The influence of ELF-MF on the level of phosphate compounds and intracellular pH was monitored by ³¹P NMR spectroscopy. Furthermore, the activity of enzymes involved in phosphate turnover, total ATPases, Na+/K+-ATPase and acid phosphatase has been measured. The exposure of snails to the ELF-MF for the period of 7 days shifted intracellular pH toward more alkaline conditions, and increased the activity of investigated enzymes. Prolonged exposure to the ELF-MF for the period of 16 days caused a decrease of PCr and ATP levels and decreased enzyme activity, compared to the 7-day treatment group. Our results can be explained in terms of: 1. increase in phosphate turnover by exposure to the ELF-MF for the period of 7 days, and 2. adaptation of phosphate metabolism in the nervous system of snails to prolonged ELF-MF exposure.

Some biochemical parameters in hemolymph of Garden snail (Helix pomatia L.) in the region of power plants of Kosovo

In current work the concentration of glucose, total proteins, cholesterol and the activity of the alkaline phosphatase in hemolymph of local population of Garden snail Helix pomatia L.(N=20), in the region contaminated by the power plants of Kosovo in Obiliq, was analyzed. The snails of control group were taken from the region of Gjilan far away from polluted area. The preliminary investigation results have shown that the concentration of the cholesterol in the hemolyph of snails from the polluted region was significantly higher whereas the activity of the enzyme alkaline phosphatase significantly lower in comparison with the snails of the control group. There was no indication of difference regarding the glucose and the total protein concentration between the analyzed snail groups.The investigation shows that the Garden snail can serve as bioindicator, whereas the changing of the hemolymph chemistry as marker for the biochemical indication of the environmental pollution effects.

Effect of alternating the magnetic feld on phosphate metabolism in the nervous system of Helix pomatia

The effect of extremely low frequency magnetic fields (50 Hz, 0.5 mT) - ELF-MF, on phosphate metabolism has been studied in the isolated ganglions of the garden snail Helix pomatia, after 7 and 16 days of snail exposure to ELF-MF. The influence of ELF-MF on the level of phosphate compounds and intracellular pH was monitored by ³¹P NMR spectroscopy. Furthermore, the activity of enzymes involved in phosphate turnover, total ATPases, Na+/K+-ATPase and acid phosphatase has been measured. The exposure of snails to the ELF-MF for the period of 7 days shifted intracellular pH toward more alkaline conditions, and increased the activity of investigated enzymes. Prolonged exposure to the ELF-MF for the period of 16 days caused a decrease of PCr and ATP levels and decreased enzyme activity, compared to the 7-day treatment group. Our results can be explained in terms of: 1. increase in phosphate turnover by exposure to the ELF-MF for the period of 7 days, and 2. adaptation of phosphate metabolism in the nervous system of snails to prolonged ELF-MF exposure.

The dependence of thermopreferendum in Helix pomatia L. on air temperature

Behavioural tests with 192 specimen of the roman garden snail Helix pomatia L. were performed in order to clarify whether the thermopreferendum of this pulmonate is influenced not only by the temperature of the substratum but also by air temperature. For this purpose, the snails were exposed to a horizontal temperature gradient of the substratum at different air temperatures between 10 and 30°C. The results show that the selection of substratum temperature depends on the air temperature: the lower the air temperature, the lower is the temperature of the substratum preferred by the snails. Obviously, the animals tend to keep the difference between air temperature and temperature of the substratum as small as possible. This behaviour might be a mechanism to reduce the temperature gradient in the snail's body and to adjust the metabolic rate to cardiac output.

Studies on lectins XL. O-glycosyl derivatives of spheron in affinity chromatography of lectins

Free monosaccharides can be used for direct glycosylation of Spheron, a spherical macroporous hydroxyyalkyl methacrylate-ethylene dimethacrylate copolymer, in a reaction that proceeds at room temperature in dioxane medium under catalysis of dry HCl or BF 3. Derivatives of L-fucose, D-galactose, D-glucose, D-mannose, N- acetyl- D- galactosamine and N- acetyl- D- glucosamine thus prepared from Spheron beads have been shown to be efficient affinity carriers in isolation of lectins from seeds of Canavalia ensiformis D.C. (concanavalin A), Dolichos biflorus L., Glycine soja (L.) Sieb. et Zucc., Lens esculenta Moench, Ricinus communis L., Ulex europaeus L. and from albumin glands of the garden snail Helix pomatia L.

Diurnal rhythms in cyclic nucleotide metabolism in Helix nervous system

Concentrations of cAMP (cyclic adenosine 3',5'-monophosphate) and cGMP (cyclic guanosine 3',5'-monophosphate), in ganglia from the garden snail Helix pomatia, vary considerably over the course of the day. There is a maximum in the concentration of both cyclic nucleotides between 08:00 and 12:00 (lights on 06:00 to 18:00), with the cAMP maximum occurring slightly later than that in cGMP. In addition there can be several smaller maxima in cAMP and cGMP levels; the timing of these can be markedly different from experiment to experiment, with cAMP and cGMP sometimes in and sometimes out of phase with each other. This pattern is observed in Helix which had been activated from the dormant state 4-6 days earlier, but is not present in dormant or in long-active animals. The cyclic nucleotide rhythm can be seen in ganglia maintained in organ culture, and persists for at least 24 hours after removal of the tissue from the animal. There appears to be little change in the level of basal or NaF-stimulated adenylate cyclase activity in Helix ganglia over the course of the day. On the other hand, both cAMP and cGMP phosphodiesterase activities exhibit rhythms which are consistent with the rhythms in cAMP and cGMP concentrations.