scholarly journals Wheel running increases hyperthermia and mortality rate following 3,4-methylenedioxymethamphetamine (MDMA) in rats

2017 ◽  
Author(s):  
M. A. Taffe

AbstractHyperthermic responses are commonly reported in cases of human medical emergency following recreational use of 3,4-methylenedioxymethamphetamine (MDMA, “Ecstasy”), but a precise determination of contributing environmental factors has been elusive given the relative scarcity of threatening and fatal reactions in humans. This study was conducted to determine if elevated physical activity contributes to hyperthermic responses to MDMA in a well controlled animal model. Unrestrained male Wistar rats were monitored with minimally-invasive radiotelemetry techniques following challenge with MDMA (1.0, 5.6 and 10.0 mg/kg, s.c.). Studies were conducted in low (23-25°C) and high (27°C) ambient temperature (TA), with and without access to an activity wheel. The study confirmed dose dependent effects on body temperature, chamber activity and wheel activity which were modified by different TA conditions. Increases in wheel and home chamber activity produced by 10 mg/kg MDMA increased the magnitude of hyperthermia under 27°C TA. Furthermore, greater subject mortality was observed in the wheel-access condition compared with the no-wheel condition. These data provide direct evidence that sustained physical activity increases the hyperthermic response to MDMA and that this is associated with increased lethality. This is the first direct experimental confirmation that increased physical activity may be a risk factor for adverse reactions to MDMA in human user populations.

2005 ◽  
Vol 289 (4) ◽  
pp. R998-R1005 ◽  
Author(s):  
Juan J. Chiesa ◽  
Montserrat Anglès-Pujolràs ◽  
Antoni Díez-Noguera ◽  
Trinitat Cambras

Both temporary access to a running wheel and temporary exposure to light systematically influence the phase producing entrainment of the circadian activity rhythm in the golden hamster ( Mesocricetus auratus). However, precise determination of entrainment limits remains methodologically difficult, because such calculations may be influenced by varying experimental paradigms. In this study, effects on the entrainment of the activity pattern during successive light-dark (LD) cycles of stepwise decreasing periods, as well as wheel running activity, were investigated. In particular, the hamster activity rhythm under LD cycles with a period (T) shorter than 22 h was studied, i.e., when the LD cycle itself had been shown to be an insufficiently strong zeitgeber to synchronize activity rhythms. Indeed, it was confirmed that animals without a wheel do not entrain under 11:11-h LD cycles (T = 22 h). Subsequently providing hamsters continuous access to a running wheel established entrainment to T = 22 h. Moreover, this paradigm underwent further reductions of the T period to T = 19.6 h without loss of entrainment. Furthermore, restricting access to the wheel did not result in loss of entrainment, while even entrainment to T = 19 h was observed. To explain this observed shift in the lower entrainment limit, our speculation centers on changes in pacemaker response facilitated by stepwise changes of T spaced very far apart, thus allowing time for adaptation.


2005 ◽  
Vol 22 (1) ◽  
pp. 76-85 ◽  
Author(s):  
Michael J. Turner ◽  
Steven R. Kleeberger ◽  
J. Timothy Lightfoot

In humans, physical activity declines with age. We tested the hypothesis that genetic background and age interact to determine daily wheel-running physical activity patterns in mice. Five female mice from ten inbred strains (A/J, AKR/J, Balb/cJ, CBA/J, C3H/HeJ, C3Heb/FeJ, C57Bl/6J, C57L/J, DBA/2J, and SWR/J) were studied for 26 wk starting at 10 wk of age. All mice were housed in separate cages, each with a running wheel and magnetic sensor. Throughout the 26-wk period, age-related change in daily duration ( P < 0.0001), daily distance ( P < 0.0001), and average velocity ( P = 0.0003) differed between the inbred strains. Unlike the other strains, SWR/J mice increased their running-wheel activity throughout the 6-mo time period. Broad-sense heritability estimations for the strains across the 26-wk period ranged between 0.410 and 0.855 for the three physical activity phenotypes. Furthermore, the broad-sense heritability estimates for daily running-wheel distance differed across time and suggested an interaction between genetic background and age on physical activity in these inbred mice.


2008 ◽  
Vol 2 (1) ◽  
pp. 17-24 ◽  
Author(s):  
Anthony Ferreira ◽  
Fabien Cornilleau ◽  
Fernando Perez-Diaz ◽  
Charles Cohen-Salmon

This study used animal models to examine potential similarities between dependence on physical activity (i.e., exercise) and dependence on morphine. Using C57BL/6 mice, the study also tested the hypothesis that physical exercise (e.g., long-term wheel running) may enhance vulnerability to the development of morphine dependence. The existence of an endorphin-related dependence induced by physical activity was also assessed. Naloxone was used to precipitate morphine withdrawal in mice accustomed to morphine. Specifically, the study sought to assess the intensity of addiction provoked by injection of morphine in mice that engaged in wheel-running activity as opposed to inactive mice. After 25 days of free access to activity wheel, mice that engaged in wheel-running demonstrated increased vulnerability to naloxone-induced withdrawal symptoms, which may be linked to activation of peripheral, as opposed to central, opioid receptors. These results indicate a behavioral interaction in which engaging in wheel running appears to potentiate the effects of morphine addiction. Implications of these findings for understanding human behavior and exercise addiction are also discussed.


2006 ◽  
Vol 21 (8) ◽  
pp. 580-588 ◽  
Author(s):  
Anthony Ferreira ◽  
Stéphanie Lamarque ◽  
Patrice Boyer ◽  
Fernando Perez-Diaz ◽  
Roland Jouvent ◽  
...  

AbstractAccording to human observations of a syndrome of physical activity dependence and its consequences, we tried to examine if running activity in a free activity paradigm, where rats had a free access to activity wheel, may present a valuable animal model for physical activity dependence and most generally to behavioral dependence. The pertinence of reactivity to novelty, a well-known pharmacological dependence predictor was also tested. Given the close linkage observed in human between physical activity and drugs use and abuse, the influence of free activity in activity wheels on reactivity to amphetamine injection and reactivity to novelty were also assessed. It appeared that (1) free access to wheel may be used as a valuable model for physical activity addiction, (2) two populations differing in activity amount also differed in dependence to wheel-running. (3) Reactivity to novelty did not appeared as a predictive factor for physical activity dependence (4) activity modified novelty reactivity and (5) subjects who exhibited a high appetence to wheel-running, presented a strong reactivity to amphetamine. These results propose a model of dependency on physical activity without any pharmacological intervention, and demonstrate the existence of individual differences in the development of this addiction. In addition, these data highlight the development of a likely vulnerability to pharmacological addiction after intense and sustained physical activity, as also described in man. This model could therefore prove pertinent for studying behavioral dependencies and the underlying neurobiological mechanisms. These results may influence the way psychiatrists view behavioral dependencies and phenomena such as doping in sport or addiction to sport itself.


2010 ◽  
Vol 46 (4) ◽  
pp. 411-417 ◽  
Author(s):  
Yang MENG ◽  
Lin GU ◽  
Wenzheng ZHANG

1968 ◽  
Vol 12 ◽  
Author(s):  
R. Goossens

A precise method for the determination of the increment of the  basal area using the PressIer bore. Refering to  previous research showing that the basal area of the corsica pine could be  characterized by an ellips, we present in this paper a precise method for the  determination of the increment of the basal area. In this method we determine  the direction of the maximum diameter, we measure this diameter and we take a  core in one of the points of tangency of the caliper with the measured tree.  The determination of the diameter perpendicular to the maximum diameter  finishes the work wich is to be done in the forest. From the classical  measurements effectuated on the core and from the measured diameters we can  then determine the form (V) and the excentricity (e). Substituting these two  parameters in the formula 2 or 2', we can also calculate the error of a  radius measured on the core with respect to the representative radius, This  error with them allow us to correct the measured value of the minimum or the  maximum radius and we will be able to do a precise determination of the  increment.


Author(s):  
Ferrari Colin ◽  
Resongles Eléonore ◽  
Freydier Rémi ◽  
Casiot Corinne

Thiol-functionalized silica powder allowed single-step purification of antimony for exploring stable Sb isotope signatures in the environment.


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