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PubMedDate not supplied

The dual role of serotonin in leech swimming.

The swimming behavior of the leech depends upon the level of serotonin in its blood stream: the higher the level, the more likely the leech is to swim. Serotonin is contained in Retzius cells, segmentally paired neurons, which release enough of this substance to affect its blood level and thus the swimming behavior of the animal. Retzius cells appear not to have synaptic effects on swim-related neurons. Pairs of other serotonin-containing neurons (cells 21 and 61) are also present in each ganglion. Stimulation of these cells can initiate swimming within seconds. In contrast to Retzius cells, neurons 21 and 61 make synaptic connections onto swim-related neurons; for example, cell 61 makes what appears to be a conductance decrease excitatory synapse onto the pattern-generating interneuron cell 208. These results suggest that the two classes of serotonin-containing neurons control the swimming behavior of the leech through two different mechanisms: Retzius cells exert a neurohormonal action whereas cells 21 and 61 act synaptically.

Animals↗
PubMed1995

The use of telemetry to record electrocardiogram and heart rate in freely swimming rats.

Measurement of parameters from the circulatory system of laboratory animals can play an important role in pharmacological or toxicological research. To study the mutual interaction between physical exercise and antioxidant systems in rats, we selected swimming as a model for exercise performance. Swimming belongs to the natural behavior of the rat, and under proper experimental conditions, it primarily involves physical exercise with little emotional arousal. Therefore, we developed a swimming basin in which the intensity of exercise could be manipulated through speed and duration of swimming. A laser beam interruption system enables the rat to be followed during each swimming session. A motor-controlled following device, consisting of a rail and sledge connected to a position sensor, contains an antenna mounted in a receiver board. In this way, we can record the electrocardiogram (ECG) and heart rate (HR) with a commercially available telemetry transmitter implanted in the peritoneal cavity of freely swimming rats and evaluate the physical fitness (condition) of the swim-trained rats.

Animals↗
PubMed1993

[Fetal heart rate monitoring during maternal swimming].

Fetal physiology during swimming in pregnancy has remained unclear. To assess the fetal status, the fetal heart rate (FHR) was measured during maternal swimming. We studied individually a group of seventeen women in normal pregnancy (during their third trimester, 35-38th week) who participated in a maternal swimming class. We adapted the Doppler ultra-sound transducer for underwater use and attached it to the mothers' abdomen. FHR was recorded before, during and after swimming. The group swam from 375 to 750 meters in 33 to 41 minutes. During swimming, motion artifacts interfered with the FHR signal and we were only able to detect FHR in eleven in the group. The mean FHR rose significantly during swimming in eight of eleven women compared to the FHR recorded before the exercise. The FHR pattern was reactive and baseline variability was preserved in all cases. No pathological deceleration was seen. It is concluded that maternal swimming under such class conditions is safe for the fetus.

Adult↗
PubMed1995

Post-swim orthostatic intolerance in a marathon swimmer.

Two swims (1993 and 1994) are described which led to post-swim orthostatic intolerance and one episode of syncope in a 50/51-yr-old well-trained and experienced marathon swimmer. The swims of 33 km and 38 km took 12 h 30 s and 17 h 35 min, respectively. Water temperature in each swim was above 23 degrees C and rectal core-temperature stayed above 37.0 degrees C. Air temperatures differed, ranging from 23 degrees to 37 degrees C and 15 degrees to 21 degrees C, respectively. Regular fluid consumption totalled approximately 5.0 and 6.0 1, respectively. Fifteen minutes after completing the 1993 swim, the swimmer experienced orthostatic intolerance and fainted at the lakeside; hospital tests revealed an elevated creatine phosphokinase (CK) of 521 U.l-1. The 1994 swim was abandoned due to severe muscle cramps and CK was found to be markedly elevated at 909 U.l-1. Orthostatic intolerance was recorded in both cases; however, no cardiac abnormalities were found. After overnight rest and intravenous saline infusions of 3.0 and 1.5 l, respectively, the orthostatic intolerance was relieved. Based on previous descriptions of exercise-associated collapse in marathon runners, the swimmer's orthostatic intolerance and syncope are attributed to blood pooling in his legs due to inactivation of the venous muscle pump on completion of the swim.

Body Temperature↗
PubMed1997

[Potassium as an indicator of anthropogenic contamination of swimming pool water].

Swimming pool water is processed, filtered and disinfected repeatedly in order to maintain hygienic conditions. Additionally, fresh water is added. However, it cannot be avoided, that the concentrations of certain components of swimming pool water will increase in the course of time. DIN 19,643 regulates that fresh water supply can be measured by nitrate concentration. Nitrate is mainly formed by oxidation of nitrogen containing organic compounds. Oxidation reactions are complex and the amount of nitrate formed by this process depends on specific factors which may vary in swimming pools with different technical equipment. Therefore nitrate is only of limited reliability to estimate fresh water addition in public swimming pools. Main sources for nitrogen containing compounds in pool water are sweat and urine which contain inorganic compounds like potassium. Potassium is a direct indicator of contamination. Its concentration is not influenced by chemical reactions because it is an inert compound. The urine release into the water of indoor pools was estimated by this parameter to be 77.5 ml/person, in outdoor pools about 60 ml. Potassium concentration in swimming pools will reach an equilibrium concentration, depending on the size of the pool, the number of bathers and the amount of fresh water added. This equilibrium concentration is mathematically calculated in a general approach. In none of 36 swimming pools where potassium concentration was measured, this calculated value was exceeded. The results indicate that the potassium concentration is a new valuable parameter to assess the quality of swimming pool water under hygienic aspects.

Fresh Water↗
PubMed1998

Bone density and mechanical properties in femoral bone of swim loaded aged mice.

Effects of swimming on bone density and mechanical properties of femur were investigated in aged male and female mice. R/1 strain of senescence accelerated mouse (SAM) at eleven months old was used. Two groups of males and two groups of females each consisting of 7 mice were used. One male and one female groups were loaded with a swim regiment of 40 min a day, 5 days a week for 6 consecutive weeks. The remaining groups were used as the controls. All mice were fed with the standard diet and water ad libitum during the experiments. The results of this study indicated that (i) the body weight was significantly (P < 0.05) lower in the swimming groups than in the control groups in both sexes. (ii) The bone density was significantly higher (P < 0.05) in the swimming groups than in the control groups in both sexes. However, there was no significant difference in cortical thickness index. (iii) In the mechanical properties of bone, there were no significant differences in the level of the maximum breaking force, the ultimate stress and the deformation between the swimming and the control groups in both sexes. However, the elasticity of the bone of the female mice in the swimming group was significantly higher (P < 0.05) than that of the control group. These results suggest that regimented swimming for the aged mice might suppress age-associated bone loss, and the effect of exercise in the females is greater that in the males.

Aging↗
PubMed1991

Immersion events in residential swimming pools. Evidence for an experience effect.

BACKGROUND: --Drowning and near-drowning in residential swimming pools are leading causes of morbidity and mortality for young children. We tested the hypothesis that the period immediately after a pool is acquired is a time of high risk for these events. This study was also designed to provide population-based data on swimming pool immersion events, regardless of severity. METHODS: --We conducted a mail survey of a probability sample of Sacramento County, California, households with in-ground swimming pools in January 1988; 80% of eligible subjects responded. Onset of exposure to a pool was defined as the month in which (1) the responding household had a pool installed, or (2) the responding household first occupied a residence with a pool. Exposures began in 1959 through 1987. RESULTS: --The home swimming pool immersion event rate was 11 per 1000 pool-years. The rate per 1000 pool-years was higher for the first 6 months of exposure than thereafter (0 to 6 months, 44; 7 to 24 months, 14; greater than 24 months, seven), but 77% of events occurred outside the high-risk period. For households whose exposures began in 1984 through 1987, the immersion event rate was 51 per 1000 pool-years overall and 123 per 1000 pool-years for the first 6 months of pool exposure; these increases probably represent underreporting of earlier events. In this group, 48% of events occurred outside the high-risk period. The family swimming pool accounted for 91% of immersion events at the respondents' homes. CONCLUSIONS: --The residential swimming pool is an important hazard for pool-owning households. The first 6 months of exposure constitute a high-risk period, but many immersion events occur later. Pool drowning prevention programs may focus on newly acquired swimming pools and their owners but should be as broad as possible to maximize their effectiveness.

California↗
PubMed1984

Trifluoperazine-induced changes in swimming behavior of paramecium: evidence for two sites of drug action.

Trifluoperazine (TFP), a drug that binds to Ca2+-calmodulin (CaM) complexes, altered swimming behavior not only in living paramecia, but also in reactivated, Triton-extracted "models" of the ciliate. By comparing the responses of living cells and models, we have ascertained that two sites of drug action exist in paramecium cilia. Swimming movements were recorded in darkfield stroboscopic flash photomicrographs; this permitted accurate quantitation of velocities and body-shape parameters. When living paramecia were incubated in a standard buffer containing 10 microM TFP, their speed of forward swimming fell over several minutes and their bodies shortened. Untreated paramecia backed up repeatedly and frequently upon transfer to a solution containing barium ions (the "barium dance"), but cells preincubated in TFP did not "dance." Instead they swam forward slowly for long periods of time without reversing and occasionally then exhibited abnormally prolonged reversals. W7 effects on swimming mimicked low doses of TFP, and the analog W5 did not visibly alter normal swimming patterns. These results suggest that TFP induces a decrease in the intracellular pCa of living paramecia, perhaps by reducing the efficiency of a calmodulin-activated calcium pump in the cell membrane. Paramecia extracted with Triton X-100 and reactivated to swim forward (7 greater than or equal to pCa greater than or equal to 6) were not affected by addition of up to 40 microM TFP to the reactivation medium. We conclude that the main drug effect in living cells is probably not at the axoneme. However, at low pCa, TFP directly affected the ciliary axoneme to shift its behavior to one characteristic of a higher pCa: TFP inhibited backward swimming in models reactivated at pCa less than 6; instead they swam forward or rocked in place. The mechanism of ciliary reversal in paramecium may therefore depend on an axonemal Ca2+-sensor, possibly bound CaM, which is affected by TFP only at low pCa, as has been postulated for other types of cilia.

Animals↗
PubMed2004

Swim bladder and posterior lateral line nerve of the nurseryfish, Kurtus gulliveri (Perciformes: Kurtidae).

The morphology of the swim bladder and inner ear of the nurseryfish, Kurtus gulliveri, appear adapted for enhanced pressure wave reception. The saccule is enlarged and surrounded by very thin bone and two large fontanelles that would present reduced resistance to pressure waves. The swim bladder is elaborate, with six dorsolaterally projecting pairs of lobes that are tightly encased in ribs and an additional caudally projecting pair of lobes encased in the first hemal spine. The ribs and musculature surrounding the swim bladder laterally are very thin, so that four or five "rib windows" are readily apparent on back-lit specimens. This swim bladder-rib configuration would also present reduced resistance to pressure waves to enhance function as a peripheral auditory structure. However, high-resolution X-ray computed tomography and dissection reveal no anterior projections of the swim bladder that could serve as a mechanical coupling to the inner ear. The posterior lateral line nerve is well developed and lies directly over the tips of the ribs encasing the swim bladder lobes. This nerve is not, however, associated with a lateral line canal and a lateral line canal is absent on most of the body. We hypothesize that the posterior lateral line nerve transmits mechanosensory information from the swim bladder.

Air Sacs↗
PubMed2006

The laterophysic connection and swim bladder of butterflyfishes in the genus Chaetodon (Perciformes: Chaetodontidae).

The laterophysic connection (LC) is an association between bilaterally paired, anterior swim bladder extensions (horns) and medial openings in the supracleithral lateral line canals that diagnoses butterflyfishes in the genus Chaetodon. It has been hypothesized that the LC makes the lateral line system sensitive to sound pressure stimuli that are transmitted by the swim bladder horns and converted to fluid flow into the lateral line system via a laterophysic tympanum. The purpose of this study was to define variation in the morphology of the LC, swim bladder and swim bladder horns among 41 Chaetodon species from all 11 Chaetodon subgenera and a species from each of four non-Chaetodon genera using gross dissection, histological analysis as well as 2D or 3D CT (computed tomographic) imaging of live, anesthetized fishes. Our results demonstrate that the lateral line system appears rather unspecialized with well-ossified narrow canals in all species examined. Two LC types (direct and indirect), defined by whether or not the paired anterior swim bladder horns are in direct contact with a medial opening in the supracleithral lateral line canal, are found among species examined. Two variants on a direct LC and four variants of an indirect LC are defined by combinations of soft tissue anatomy (horn length [long/short] and width [wide/narrow], number of swim bladder chambers [one/two], and presence/absence of mucoid connective tissue in the medial opening in the supracleithrum). The combination of features defining each LC variant is predicted to have functional consequences for the bioacoustics of the system. These findings are consistent with the recent discovery that Chaetodon produce sounds during social interactions. The data presented here provide the comparative morphological context for the functional analysis of this novel swim bladder-lateral line connection.

Air Sacs↗
PubMed1994

How swimming fish use slow and fast muscle fibers: implications for models of vertebrate muscle recruitment.

We quantified the intensity and duration of electromyograms (emgs) from the red and white axial muscles in five bluegill sunfish (Lepomis macrochirus) which performed three categories of behavior including steady swimming and burst and glide swimming at moderate and rapid speeds. Steady swimming (at 2 lengths/s) involved exclusively red muscle activity (mean posterior emg duration = 95 ms), whereas unsteady swimming utilized red and white fibers with two features of fiber type recruitment previously undescribed for any ectothermic vertebrate locomotor muscle. First, for moderate speed swimming, the timing of red and white activity differed significantly with the average onset time of white lagging behind that of red by approximately 40 ms. The durations of these white emgs were shorter than those of the red emgs (posterior mean = 82 ms) because offset times were effectively synchronous. Second, compared to steady and moderate speed unsteady swimming, the intensity of red activity during rapid unsteady swimming decreased while the intensity of white muscle activity (mean white emg duration = 33 ms) increased. Decreased red activity associated with increased white activity differs from the general pattern of vertebrate muscle recruitment in which faster fiber types are recruited in addition to, but not to the exclusion of, slower fiber types.

Animals↗
PubMed1996

Pretreatment with pertussis toxin spinally, but not supraspinally, blocks the cold water swimming-induced antinociception in the mouse.

Mice exposed to cold water swimming (4 degrees C) for 3 min produced a marked antinociception. Experiments were designed to determine whether pretreatment with pertussis toxin given intrathecally (i.t.) or intracerebroventricularly (i.c.v.) attenuates cold water swimming-induced antinociception in male ICR mice. Antinociception was measured by the tail-flick test 7 min after cold water swimming. I.t. pretreatment with pertussis toxin at a dose of 0.5 microgram for 24-96 h caused a time-dependent attenuation of cold water swimming-induced antinociception. Moreover, i.t. pretreatment with pertussis toxin at doses from 0.125 to 0.5 microgram for 96 h attenuated cold water swimming-induced antinociception in a dose-dependent manner. However, i.c.v. pretreatment with pertussis toxin at doses from 0.125 to 0.5 microgram for 24-96 h did not affect the cold water swimming-induced antinociception. The present results suggest that pertussis toxin-sensitive Gi/G(o) proteins in spinal cord, but not at the supraspinal sites, are involved in cold water swimming-induced antinociception.

Animals↗
PubMed2005

Asymmetric swimming pattern of Vibrio alginolyticus cells with single polar flagella.

The swimming pattern of bacteria with single polar flagella has usually been described as "run and reverse". We observed the swimming traces of monotrichously flagellated Vibrio alginolyticus cells and examined the relationship between the swimming pattern and the sense of progress. Swimming in regions other than a solid surface was confirmed to be linear run and reverse. Near a solid surface, the traces consisted of "run and arc"; the cells were found to curve sharply during backward swimming, while they progressed linearly during forward swimming. The "run and arc" swimming pattern may play an important role in the chemotaxis strategy of marine bacteria at solid surfaces.

Adaptation, Physiological↗
PubMed1998

Separation of motile spermatozoa from frozen-thawed buffalo semen: swim-up vs filtration procedures.

Three experiments were conducted to maximize the recovery rate of motile spermatozoa from frozen-thawed buffalo semen. In Experiment 1, the swim-up of motile spermatozoa was performed in the presence or absence of HEPES in TALP medium and CO2 in the environment. The recovery rate of motile spermatozoa in TALP medium (control), TALP + HEPES + CO2, TALP + HEPES and TALP + CO2 was 15, 18, 12 and 10%, respectively (P > 0.05), with sperm motility at 87, 89, 90 and 90%, respectively (P > 0.05). In Experiment 2, the pH of TALP medium was adjusted to 7.0, 7.5, 8.0, 8.5 and 9.0, and swim-up procedure was performed in the presence of HEPES and CO2. The recovery rate of motile spermatozoa at different pH was 14, 20, 24, 27 and 16%, respectively (P < 0.05). Motility of separated spermatozoa was 88, 91, 90, 89 and 90%, respectively (P > 0.05). In Experiment 3, the efficiency of ion-exchange filtration and Swim-up procedure in separating motile spermatozoa from frozen-thawed buffalo semen was compared. The recovery rate of motile spermatozoa was 95% in filtration procedure and 33% in swim-up procedure (P < 0.005). In all experiments, normal acrosomes did not vary due to treatments (P > 0.05). In conclusion, HEPES and CO2 had no significant effect on swim-up of buffalo spermatozoa. The pH 8.5 of TALP improved the recovery rate of motile spermatozoa in swim-up procedure. The ion-exchange filtration was found superior to swim-up procedure in harvesting maximum number of motile spermatozoa from frozen-thawed buffalo semen (95 vs 33%; P < 0.001).

Animals↗
PubMed1988

Host-finding in Trichobilharzia ocellata cercariae: swimming and attachment to the host.

The cercaria of Trichobilharzia ocellata finds and identifies its duck host with a series of different behavioural phases. Dispersal and selection of the water surface as microhabitat is achieved by an intermittent swimming behaviour, which is governed by the interplay of passive dropping with forward and backward swimming movements and includes a positive phototactic and a geonegative orientation. Then the cercariae tend to cling to the water surface in an energy-saving resting position. A movement towards the duck feet as the site of entry occurs when shadows evoke forward swimming movements, which are directed away from the source of light, i.e. normally downwards. Forward swimming movements are also stimulated by touch, but only in free-swimming cercariae and not when these are in the resting position. Attachments occur only when a substrate is touched during forward swimming movements. Attachments are stimulated by warm substrates (1 degrees C temperature difference triggers a nearly maximal response) and by chemical components of duck-foot skin, and the readiness to attach is increased when the forward swimming movement is started by shadow stimuli.

Animals↗
PubMed2001

Influence of swim-up method on the recovery of spermatozoa from different types of semen samples.

PURPOSE: To compare the effectiveness of swim-up method, using different types of semen samples. METHODS: In this retrospective study undertaken in university medical college infertility centre, subfertile couples undergoing Intra Uterine Insemination were selected. A total of 600 semen samples used for the preparation of sperm samples using swim-up method were analyzed. Relative Yield was calculated from the sperm count and motility before and after swim up from each semen sample in six different groups. RESULT(S): Statistically significant increase in relative yield was found in oligospermic samples (20.41) followed by teratospermia (16.98). However, relative yield was low in asthenospermic (11.97) and normal (> 60 million/ml) samples (11.66). CONCLUSION(S): Semen samples with good sperm count resulted in poor recovery after swim up. Swim-up method appears to be effective for oligospermic samples. Modifications like multiple tube swim up, using appropriate incubation time based on the initial semen parameter, will enhance the sperm yield after swim up.

Humans↗
PubMed2003

A new antifouling bioassay monitoring brown algal spore swimming behaviour in the presence of echinoderm extracts.

Epibiosis, the colonization of biogenic surfaces by epibiotic organisms such as bacteria, filamentous algae, and sessile invertebrates, poses a major threat to the fitness and survival of macroorganisms which could potentially be fouled. Fouling of artificial submerged structures can also cause severe economic problems, making the need for refined bioassays to determine the efficacy of potential antifouling compounds even more important. The aim of this study was to use the distinct swimming behaviour of zoospores of the fouling brown alga Hincksia irregularis to develop a new laboratory antifouling bioassay to test the effect of marine natural products. Spores were exposed to different concentrations of aqueous and organic extracts from body walls of sympatric echinoderms (Asteroidea: Luidia clathrata, Astropecten articulatus; Ophiuroidea: Astrocyclus caecilia). Computer-assisted motion analysis was used to distinguish between the straight and fast swimming movements of undisturbed spores (controls) and the helical and erratic swimming patterns of chemically irritated spores, using the quantitative parameters rate of direction change (RCD) and swimming speed (SPD). The ratio RCD/SPD of spore swimming paths at extract treatments compared to controls can be used to quantify the detrimental effect of echinoderm extracts. Echinoderm extracts had significant effects on spore swimming behaviour at concentrations three orders of magnitude lower than that present naturally in the echinoderm body walls (mg extract/dry weight echinoderm body wall). Comparative studies on spore settlement and germination under similar treatment conditions show that changes in spore swimming behaviour reflect decreased fitness and survivourship of algal spores. It is suggested that this bioassay can be used to screen potential antifouling extracts and compounds at very low concentrations, making this assay particularly suitable for detection of concentration dependent effects and for bioassay-guided fractionation of extracts to identify active compounds.

Analysis of Variance↗
PubMed1992

In-vitro fertilization in cases with severe sperm defect: use of a swim-across technique and medium supplemented with follicular fluid.

The purpose of this study was to evaluate a new method of in-vitro fertilization (IVF) in patients with severe sperm defects. Unlike the conventional swim-up method, spermatozoa and oocytes are placed in opposite corners of the bottom of the incubation dish so that sperm swimming is horizontal instead of vertical. Another difference between the swim-across and swim-up techniques is that the incubation medium is supplemented with 20% follicular fluid. After a randomized series (protocol I) of 15 IVF attempts had demonstrated that swim-across was more effective than swim-up in terms of fertilization and cleavage, we began a second series (protocol II) using only swim-across. A total of 124 couples with motile sperm counts less than 1 x 10(6) spermatozoa/ml of semen were included in protocol II. Clinical parameters (age, tubal damage) and number of recovered oocytes were recorded and compared in patients who did (group A: n = 94) and did not (group B: n = 74) achieve fertilization. In group A the fertilization rate was 36.7% and, out of the 94 transfers that were made, there were 21 clinical pregnancies and 12 full-term pregnancies with 16 live births. The number of oocytes collected (12 versus 7.7, P less than 0.001) and the incidence of tubal damage (50% versus 24.3%, P less than 0.001) was significantly higher in group A than in group B. Using logistic regression analysis, we showed a significant correlation between fertilization and progressive motility, percentage normal spermatozoa, number of recovered oocytes and tubal damage.(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗