- MeSH
- dítě MeSH
- lidé MeSH
- mladiství MeSH
- narkolepsie * farmakoterapie MeSH
- stimulanty centrálního nervového systému terapeutické užití farmakologie MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- mladiství MeSH
- Publikační typ
- dopisy MeSH
Aging is associated with neurodegeneration and a loss of muscle function, especially in lower-limb muscles. While caffeine may augment muscle force generation through multiple effects on the central nervous system, no studies have yet compared the effects of caffeine on force-generating capacity between younger and older men, who might respond differently due to age-related changes in the structures on which caffeine acts. In a double-blind, controlled trial, 22 younger (25 ± 5 years) and 21 older (68 ± 6 years) men were tested for isometric plantarflexor torque on two separate days (2-7 days apart) before and 60 min after ingesting 3 mg/kg (∼2 cups of coffee) of caffeine or placebo. No effects of caffeine ingestion on peak torque or rate of torque development were detected in either older or younger men. Therefore, 3 mg/kg of caffeine may not acutely counteract age-related decreases in force capacity of the functionally important plantarflexor muscles.
- MeSH
- dvojitá slepá metoda MeSH
- kofein * farmakologie MeSH
- kosterní svaly fyziologie MeSH
- lidé MeSH
- přijímání potravy MeSH
- senioři MeSH
- stimulanty centrálního nervového systému * farmakologie MeSH
- točivý moment MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- randomizované kontrolované studie MeSH
RATIONALE: Exposure to rewards can alter behavioral reactivity to them. For example, stimulants sensitize locomotor activation, whereas sexual experience sensitizes copulatory behaviors. Moreover, rewards can cross-sensitize one another. Although stimulants are known to cross-sensitize locomotor effects, the evidence for cross-sensitization between stimulants and sex is less clear. OBJECTIVES: This study determined the effects of single and repeated pre-exposure to methylphenidate (MPH) or sex on one another in adult male rats. METHODS: Cross-sensitization between MPH (5 mg/kg) and sex (30 min with sexually experienced female) was examined. Adult male rats were pre-exposed to 0, 1, or 10 trials of either sex or MPH before being exposed to the other reward. Locomotor chambers were used in MPH trials. Bilevel chambers were used in sexual trials, and sexual behaviors were video scored. RESULTS: The amount of prior sexual experience differentially influenced the ceiling of MPH-dependent sensitization; in the last drug trial, locomotion was highest in males given 1 previous sexual trial compared with 0 or 10. Compared with MPH-naive males, pre-exposure to MPH (1 and 10 trials) reduced the number of ejaculations without impacting sexual performance (intromission/mount latency and frequency). CONCLUSIONS: These findings indicate that the degree of pre-exposure to a reward can differentially affect reactivity to novel rewards. The results showed that previous findings of cross-sensitization between amphetamine and sex do not extend to MPH. However, exposure to MPH prior to sexual experience can increase the amount of sexual stimulation needed to achieve ejaculation.
- MeSH
- amfetamin farmakologie MeSH
- kopulace MeSH
- krysa rodu rattus MeSH
- methylfenidát * farmakologie MeSH
- stimulanty centrálního nervového systému * farmakologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Methylphenidate is a stimulant used to treat attention deficit and hyperactivity disorder (ADHD). In the last decade, illicit use of methylphenidate has increased among healthy young adults, who consume the drug under the assumption that it will improve cognitive performance. However, the studies that aimed to assess the methylphenidate effects on memory are not consistent. Here, we tested whether the effect of methylphenidate on a spatial memory task can be explained as a motivational and/or a reward effect. We tested the effects of acute and chronic i.p. administration of 0.3, 1 or 3 mg/kg of methylphenidate on motivation, learning and memory by using the 8-arm radial maze task. Adult male Wistar rats learned that 3 of the 8 arms of the maze were consistently baited with 1, 3, or 6 sucrose pellets, and the number of entries and reentries into reinforced and non-reinforced arms of the maze were scored. Neither acute nor chronic (20 days) methylphenidate treatment affected the number of entries in the non-baited arms. However, chronic, but not acute, 1-3 mg/kg methylphenidate increased the number of reentries in the higher reward arms, which suggests a motivational/rewarding effect rather than a working memory deficit. In agreement with this hypothesis, the methylphenidate treatment also decreased the approach latency to the higher reward arms, increased the approach latency to the low reward arm, and increased the time spent in the high, but not low, reward arm. These findings suggest that methylphenidate may act more as a motivational enhancer rather than a cognitive enhancer in healthy people.
- MeSH
- hyperkinetická porucha * farmakoterapie MeSH
- krysa rodu rattus MeSH
- methylfenidát * farmakologie terapeutické užití MeSH
- motivace MeSH
- odměna MeSH
- potkani Wistar MeSH
- stimulanty centrálního nervového systému * farmakologie terapeutické užití MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Naphyrone, also known as NRG-1, is a novel psychoactive substance (NPS), a cathinone with stimulatory properties available on the grey/illicit drug market for almost a decade. It is structurally related to infamously known powerful stimulants with the pyrovalerone structure, such as alpha-pyrrolidinovalerophenone (α-PVP) or methylenedioxypyrovalerone (MDPV) that are labeled as a cheap replacement for cocaine and other stimulants. Despite the known addictive potential of α-PVP and MDPV, there are no studies directly evaluating naphyrone's addictive potential e.g., in conditioned place preference (CPP) test or using self-administration. Therefore, our study was designed to evaluate the addictive potential in a CPP test in male Wistar rats and compare its effect to another powerful stimulant with a high addictive potential - methamphetamine. Naphyrone increased time spent in the drug-paired compartment with 5 and 20 mg/kg s.c. being significant and 10 mg/kg s.c. reaching the threshold (p = 0.07); the effect was comparable to that of methamphetamine 1.5 mg/kg s.c. The lowest dose, naphyrone 1 mg/kg s.c., had no effect on CPP. Interestingly, no dose response effect was detected. Based on these data, we are able to conclude that naphyrone has an addictive potential and may possess a significant risk to users.
- MeSH
- alkaloidy farmakologie MeSH
- chování zvířat účinky léků MeSH
- klasické podmiňování účinky léků MeSH
- krysa rodu rattus MeSH
- methamfetamin aplikace a dávkování farmakologie MeSH
- modely nemocí na zvířatech MeSH
- pentanony aplikace a dávkování farmakologie MeSH
- poruchy spojené s užíváním psychoaktivních látek * MeSH
- potkani Wistar MeSH
- pyrrolidiny aplikace a dávkování farmakologie MeSH
- stimulanty centrálního nervového systému aplikace a dávkování farmakologie MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Naphthylpyrovalerone (naphyrone) is a pyrovalerone cathinone that potently inhibits monoamine transporters and provides stimulatory-entactogenic effects. Little is known about the safety of naphyrone or its effects in vivo, and more research is needed to acquire knowledge about its fundamental effects on physiology and behaviour. Our objective was to investigate naphyrone's pharmacokinetics, acute toxicity, hyperthermic potential and stimulatory and psychotomimetic properties in vivo in male Wistar rats. Pharmacokinetics after 1 mg/kg subcutaneous (sc.) naphyrone were measured over 6 h in serum, the brain, liver and lungs. Rectal temperature (degree Celsius) was measured over 10 h in group-versus individually housed rats after 20 mg/kg sc. In the behavioural experiments, 5, 10 or 20 mg/kg of naphyrone was administered 15 or 60 min prior to testing. Stimulation was assessed in the open field, and sensorimotor processing in a prepulse inhibition (PPI) task. Peak concentrations of naphyrone in serum and tissue were reached at 30 min, with a long-lasting elevation in the brain/serum ratio, consistent with observations of lasting hyperlocomotion in the open field and modest increases in body temperature. Administration of 20 mg/kg transiently enhanced PPI. Naphyrone crosses the blood-brain barrier rapidly and is eliminated slowly, and its long-lasting effects correspond to its pharmacokinetics. No specific signs of acute toxicity were observed; therefore, clinical care and harm-reduction guidance should be in line with that available for other stimulants and cathinones.
- MeSH
- krysa rodu rattus MeSH
- pentanony farmakokinetika farmakologie MeSH
- potkani Wistar MeSH
- pyrrolidiny farmakokinetika farmakologie MeSH
- stimulanty centrálního nervového systému farmakokinetika farmakologie MeSH
- tělesná teplota účinky léků MeSH
- termoregulace účinky léků MeSH
- zakázané drogy farmakokinetika farmakologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Caffeine is well known for reducing fatigue and its effect on behavior is widely studied. Usually, caffeine is not ingested in its pure form but rather in sugar-sweetened beverages such as cola. Our aim was to compare the acute effect of cola and caffeine on locomotor activity. Rats and flies ingested cola or caffeine solution for 24 hours. The open field test revealed higher locomotor activity in cola groups for both flies and rats. Surprisingly, no differences have been observed between caffeineand control group. We conclude that caffeine itself does not explain the effect of cola on locomotor activity. Effect of cola cannot be generalized and interpreted for any caffeinated drink with other contents. Rather, the observed effect on locomotor activity may be caused by interaction of caffeine with other substances present in cola.
- MeSH
- časové faktory MeSH
- Drosophila melanogaster účinky léků MeSH
- kofein farmakologie MeSH
- lokomoce účinky léků MeSH
- stimulanty centrálního nervového systému farmakologie MeSH
- sycené nápoje * MeSH
- test otevřeného pole účinky léků MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
Methylphenidate is commonly used for the treatment of attention deficit hyperactivity disorder. The cardiovascular safety of methylphenidate has been a subject of debate with some studies indicating that methylphenidate increases the likelihood of experiencing a myocardial infarction. However, it is unknown whether methylphenidate worsens the extent of injury during an ischemic insult. The purpose of this study was to determine whether short term exposure to methylphenidate increases the extent of myocardial injury during an ischemic insult. Male and female rats received methylphenidate (5 mg/kg/day) or saline for 10 days by oral gavage. Hearts were subjected to 20 min of ischemia and 2 h of reperfusion on a Langendorff isolated heart apparatus on day 11. Cardiac contractile function was monitored via an intraventricular balloon and myocardial injury was assessed by triphenyltetrazolium chloride staining. Methylphenidate significantly increased locomotor activity in male and female rats, confirming absorption of this psychostimulant into the central nervous system. Male hearts had significantly larger infarcts than female hearts, but methylphenidate had no impact on infarct size or postischemic recovery of contractile function in hearts of either sex. These data indicate that methylphenidate does not increase the extent of injury induced by an ischemic insult.
- MeSH
- infarkt myokardu chemicky indukované patologie MeSH
- ischemická choroba srdeční chemicky indukované patologie MeSH
- kontrakce myokardu účinky léků MeSH
- krysa rodu rattus MeSH
- methylfenidát škodlivé účinky farmakologie MeSH
- modely nemocí na zvířatech MeSH
- obnova funkce MeSH
- potkani Sprague-Dawley MeSH
- rozvrh dávkování léků MeSH
- stimulanty centrálního nervového systému farmakologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Drug addiction and its consequences on social life and behavior is currently a worldwide problem. Methamphetamine (MA) is one of the most abused psychostimulants in the Czech Republic. MA elevates mood, increases concentration, reduces appetite, and promotes weight loss. However, high doses and long-term abuse can induce psychosis, hallucinations, paranoia, violent behavior, and can lead to cardiovascular problems. Regarding its high prevalence and negative impact on health and social life, MA needs to be fully investigated. Previous studies have demonstrated the impairing effect of MA drug abuse on female behavior. However, MA's influence on male sexual behavior is not entirely clear. The aim of this study was to examine the effect of MA exposure on sexual behavior and spontaneous locomotor activity of adult male rats. MA was administrated subcutaneously at a dose of 5 mg/kg daily for a period of 30 days. The control group was exposed to saline (SA) at the same time and same volume. At the end of the application period, exposed male rats were paired with non-treated female rats, and their behavior was recorded for 2 h. Sexual mating behavior was described in terms of mounting frequency, intromission frequency, ejaculation frequency, sniffing time, intromission latency and the post-ejaculatory interval. Spontaneous locomotor activity in postnatally exposed male rats was studied using the Laboras apparatus. Acute doses of MA (1 mg/kg) or SA were administrated to probe the sensitizing effect of previous chronic MA exposure. Afterward, the animal was placed in an unknown environment and monitored for 1 h. Behavior was automatically evaluated using Laboras software by analyzing the following parameters: duration of locomotion (s), duration of immobility (s), rearing (vertical exploratory behavior), time spent grooming (s), average speed (mm/s), and distance traveled (m). Our results indicate that MA administration has a negligible effect on the sexual behavior of adult male rats. However, more experiments have to be performed to examine the influence of MA exposure on spermatogenesis and the behavior of offspring. Data from the Laboras test showed that MA exposure has a significant effect on locomotor activity in both acute as well as subchronic MA application. In conclusion, our results show that administration of MA in adult male rats does not affect sexual performance and motivation but does increase locomotor and exploratory activity in an unknown environment.
Zneužívanie psychostimulačných liekov bez medicínskej indikácie za účelom zlepšenia kognitívnych funkcií - takzvaného „mozgového dopingu“ – má celosvetovo neustále stúpajúci trend. Vzhľadom na vysoké riziko vzniku závažných nežiaducich účinkov vrátane potenciálu rozvoja závislosti, a tiež s ohľadom na fakt, že dlhodobé následky užívania zdravými jedincami nie sú preskúmané, môžu stimulanciá predstavovať riziko, ktorého dopad zatiaľ nedokážeme odhadnúť. Fenomén mozgového dopingu sa stáva vážnym problémom verejného zdravotníctva v mnohých krajinách sveta a je jednou z najkontroverznejších tém moderných neurovedných disciplín.
The misuse of prescription stimulants without medical indication with the aim of improving cognitive functions - the so-called “brain doping” – increases worldwide. Because of the high risk of serious adverse effects, including the potential for development of addiction, and also due to the fact that the long-term effects of use by healthy individuals are not fully explored, stimulants can pose a risk that we can not estimate yet. The phenomenon of brain doping has become a serious general health issue in many countries of the world and is one of the most controversial topics of modern neuroscience.
- Klíčová slova
- mozkový doping,
- MeSH
- hyperkinetická porucha diagnóza farmakoterapie patologie MeSH
- lidé MeSH
- methylfenidát škodlivé účinky MeSH
- mozek účinky léků MeSH
- nelegální distribuce léčiv na předpis * etika MeSH
- poruchy spojené s užíváním psychoaktivních látek MeSH
- prevalence MeSH
- rizikové faktory MeSH
- stimulanty centrálního nervového systému * aplikace a dávkování farmakologie terapeutické užití MeSH
- studenti * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
- Geografické názvy
- Slovenská republika MeSH
