The hippocampus is important for learning tasks, such as conditioned place preference (CPP), which is widely used as a model for studying the reinforcing effects of drugs with dependence liability. Long-term opiate use may produce maladaptive plasticity in the brain structures involved in learning and memory, such as the hippocampus. We investigated the phenomenon of conditioning with morphine on the cell density of female rat hippocampus. Forty-eight female Wistar rats weighing on average 200-250 g were used. Rats were distributed into eight groups. Experimental groups received morphine daily (three days) at different doses (2.5, 5, 7.5 mg/kg) and the control-saline group received normal saline (1 ml/kg), and then the CPP test was performed. Three sham groups received only different doses (2.5, 5, 7.5 mg/kg) of morphine without CPP test. Forty-eight hours after behavioural testing animals were decapitated under chloroform anaesthesia and their brains were fixed, and after tissue processing, slices were stained with cresyl violet for neurons and phosphotungstic acid haematoxylin for astrocytes. The maximum response was obtained with 5 mg/kg of morphine. The density of neurons in CA1 and CA3 areas of hippocampus after injection of morphine and CPP was decreased. The number of astrocytes in different areas of hippocampus was increased after injection of morphine and CPP. It seems that the effective dose was 5 mg/kg, as it led to the CPP. We concluded that both injection of mor phine and CPP can decrease the density of neurons and also increase the number of astrocytes in the rat hippocampus.

• MeSH
• astrocyty cytologie   účinky léků   MeSH
• benzoxaziny chemie   MeSH
• chování zvířat MeSH
• hematoxylin chemie   MeSH
• hipokampus cytologie   účinky léků   fyziologie   MeSH
• krysa rodu rattus MeSH
• kyselina fosfowolframová chemie   MeSH
• lokomoce MeSH
• morfin MeSH
• neurony cytologie   účinky léků   MeSH
• podmiňování (psychologie) * MeSH
• potkani Wistar MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

• Publikační typ
• abstrakt z konference 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

An increasing number of studies over the past few years have demonstrated ghrelin's role in alcohol, cocaine and nicotine abuse. However, the role of ghrelin in opioid effects has rarely been examined. Recently we substantiated in rats that ghrelin growth hormone secretagogue receptors (GHS-R1A) appear to be involved in acute opioid-induced changes in the mesolimbic dopaminergic system associated with the reward processing. The aim of the present study was to ascertain whether a ghrelin antagonist (JMV2959) was able to inhibit morphine-induced biased conditioned place preference and challenge-morphine-induced accumbens dopaminergic sensitization and behavioral sensitization in adult male rats. In the place preference model, the rats were conditioned for 8 days with morphine (10 mg/kg s.c.). On the experimental day, JMV2959 (3 and 6 mg/kg i.p.) or saline were administered before testing. We used in vivo microdialysis to determine changes of dopamine and its metabolites in the nucleus accumbens in rats following challenge-morphine dose (5 mg/kg s.c.) with or without JMV2959 (3 and 6 mg/kg i.p.) pretreatment, administered on the 12th day of spontaneous abstinence from morphine repeated treatment (5 days, 10-40 mg/kg). Induced behavioral changes were simultaneously monitored. Pretreatment with JMV2959 significantly and dose dependently reduced the morphine-induced conditioned place preference and significantly and dose dependently reduced the challenge-morphine-induced dopaminergic sensitization and affected concentration of by-products associated with dopamine metabolism in the nucleus accumbens. JMV2959 pretreatment also significantly reduced challenge-morphine-induced behavioral sensitization. Our present data suggest that GHS-R1A antagonists deserve to be further investigated as a novel treatment strategy for opioid addiction.

• MeSH
• dopamin * metabolismus   MeSH
• glycin analogy a deriváty   farmakologie   MeSH
• krysa rodu rattus MeSH
• mikrodialýza metody   MeSH
• morfin aplikace a dávkování   antagonisté a inhibitory   MeSH
• nucleus accumbens účinky léků   metabolismus   MeSH
• operantní podmiňování účinky léků   fyziologie   MeSH
• opioidní analgetika aplikace a dávkování   antagonisté a inhibitory   MeSH
• potkani Wistar MeSH
• receptory ghrelinu antagonisté a inhibitory   metabolismus   MeSH
• triazoly farmakologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

• Publikační typ
• abstrakty MeSH

The extended occurrence of fentanils abuse associated with the dramatic increase in opioid fatal overdoses and dependence strongly emphasizes insufficiencies in opioid addiction treatment. Recently, the growth hormone secretagogue receptor (GHS-R1A) antagonism was proposed as a promising mechanism for drug addiction therapy. However, the role of GHS-R1A and its endogenous ligand ghrelin in opioid abuse is still unclear. Therefore, the aim of our study was to clarify whether the GHS-R1A antagonist JMV2959 could reduce the fentanyl-induced conditioned place preference (CPP), the fentanyl intravenous self-administration (IVSA), and the tendency to relapse, but also whether JMV2959 could significantly influence the fentanyl-induced dopamine efflux in the nucleus accumbens (NAC) in rats, that importantly participates in opioids' reinforcing effects. Following an ongoing fentanyl self-administration, JMV2959 3 mg/kg was administered intraperitoneally 20 minutes before three consequent daily 360-minute IVSA sessions under a fixed ratio FR1, which significantly reduced the number of active lever-pressing, the number of infusions, and the fentanyl intake. Pretreatment with JMV2959 also reduced the fentanyl-seeking/relapse-like behaviour tested in rats on the 12th day of the forced abstinence period. Pretreatment with JMV2959 significantly and dose-dependently reduced the manifestation of fentanyl-CPP. The fentanyl-CPP development was reduced after the simultaneous administration of JMV2959 with fentanyl during conditioning. The JMV2959 significantly reduced the accumbens dopamine release induced by subcutaneous and intravenous fentanyl. Simultaneously, it affected the concentration of byproducts associated with dopamine metabolism in the NAC. Our findings suggest that GHS-R1A importantly participates in the rewarding/reinforcing effects of fentanyl.

• MeSH
• autoaplikace MeSH
• dopamin metabolismus   MeSH
• fentanyl aplikace a dávkování   škodlivé účinky   MeSH
• ghrelin metabolismus   MeSH
• glycin analogy a deriváty   farmakologie   MeSH
• intravenózní podání MeSH
• krysa rodu rattus MeSH
• narkotika aplikace a dávkování   škodlivé účinky   MeSH
• nucleus accumbens účinky léků   MeSH
• operantní podmiňování účinky léků   MeSH
• potkani Wistar MeSH
• receptory ghrelinu antagonisté a inhibitory   MeSH
• triazoly farmakologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Drug abuse of pregnant women is a growing problem. The effect of prenatal drug exposure may have devastating effect on development of the offsprings that may be long-term or even permanent. One of the most common drug abused by pregnant women is methamphetamine (MA), which is also the most frequently abused illicit drug in the Czech Republic. Our previous studies demonstrated that prenatal MA exposure alters behavior, cognition, pain and seizures in adult rats in sex-specific manner. Our most recent studies demonstrate that prenatal MA exposure makes adult rats more sensitive to acute injection of the same or related drugs than their controls. The aim of the present study was to examine the effect of prenatal MA exposure on drugseeking behavior of adult male rats tested in the Conditioned place preference (CPP). Adult male rats were divided to: prenatally MA-exposed (5 mg/kg daily for the entire prenatal period), prenatally saline-exposed (1 ml/kg of physiological saline) and controls (without maternal injections). The following drugs were used in the CPP test in adulthood: MA (5 mg/kg), amphetamine (5 mg/kg), cocaine (5 and 10 mg/kg), morphine (5 mg/kg), MDMA (5 mg/kg) and THC (2 mg/kg). Our data demonstrated that prenatally MA-exposed rats displayed higher amphetamine-seeking behavior than both controls. MA as well as morphine induced drug-seeking behavior of adult male rats, however this effect did not differ based on the prenatal MA exposure. In contrast, prenatal MA exposure induced rather tolerance to cocaine than sensitization after the conditioning in the CPP. MDMA and THC did not induce significant effects. Even though the present data did not fully confirmed our hypotheses, future studies are planned to test the drug-seeking behavior also in self-administration test.

• MeSH
• amfetamin farmakologie   škodlivé účinky   MeSH
• chování zvířat účinky léků   MeSH
• krysa rodu rattus MeSH
• lidé MeSH
• methamfetamin farmakologie   škodlivé účinky   MeSH
• N-methyl-3,4-methylendioxyamfetamin farmakologie   škodlivé účinky   MeSH
• náchylnost k nemoci MeSH
• podmiňování (psychologie) účinky léků   MeSH
• poruchy spojené s užíváním psychoaktivních látek * etiologie   metabolismus   psychologie   MeSH
• potkani Wistar MeSH
• stimulanty centrálního nervového systému * farmakologie   škodlivé účinky   MeSH
• těhotenství MeSH
• zpožděný efekt prenatální expozice * etiologie   metabolismus   psychologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• lidé MeSH
• mužské pohlaví MeSH
• těhotenství MeSH
• ženské pohlaví MeSH
• zvířata MeSH

Chronic constriction injury to the sciatic nerve was used as an animal model of neuropathic pain. Instead of frequently used reflex-based tests we used an operant thermal place preference test to evaluate signs of neuropathic pain and the effect of baclofen administration in rats with neuropathy. Chronic constriction injury was induced by four loose ligations of the sciatic nerve. Thermal place preference (45 °C vs. 22 °C and 45 °C vs. 11 °C) was measured after the ligation and after the administration of baclofen in sham and experimental rats. Rats with the chronic constriction injury spent significantly less time on the colder plate compared to sham operated animals at the combination 45 °C vs. 11 °C. After administration of baclofen (10 mg/kg s.c.), the aversion to the colder plate in rats with chronic constriction injury disappeared. At the combination 45 °C vs. 22 °C, no difference in time spent on colder and/or warmer plate was found between sham and experimental animals. These findings show the importance of cold allodynia evaluation in rats with chronic constriction injury and the effectiveness of baclofen in this neuropathic pain model.

• MeSH
• baklofen farmakologie   terapeutické užití   MeSH
• centrálně působící myorelaxancia farmakologie   terapeutické užití   MeSH
• konstrikce MeSH
• krysa rodu rattus MeSH
• měření bolesti metody   psychologie   MeSH
• nemoci periferního nervového systému farmakoterapie   psychologie   MeSH
• nemoci sedacího nervu farmakoterapie   psychologie   MeSH
• nízká teplota * MeSH
• operantní podmiňování účinky léků   fyziologie   MeSH
• potkani Wistar MeSH
• vysoká teplota * MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

• MeSH
• krysa rodu rattus MeSH
• modely nemocí na zvířatech MeSH
• N-methyl-3,4-methylendioxyamfetamin farmakologie   MeSH
• porucha chování MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• zvířata MeSH

Methamphetamine abuse imposes a significant burden on individuals and society worldwide, and an effective therapy of methamphetamine addiction would provide distinguished social benefits. Ghrelin significantly participates in reinforcing neurobiological mechanisms of stimulants, including amphetamines; thus, ghrelin antagonism is proposed as a promising addiction treatment. The aim of our study was to elucidate whether the pretreatment with growth hormone secretagogue receptor (GHS-R1A) antagonist, substance JMV2959, could reduce the methamphetamine intravenous self-administration (IVSA) and the tendency to relapse, and whether JMV2959 could reduce or prevent methamphetamine-induced conditioned place preference (CPP) in rats. Following an adequate maintenance period, JMV2959 3 mg/kg was administered intraperitoneally 20 min before three consequent daily 180 min sessions of methamphetamine IVSA under a fixed ratio FR1, which significantly reduced the number of active lever-pressings, the number of infusions, and the amount of the consumed methamphetamine dose. Pretreatment with JMV2959 also reduced or prevented relapse-like behavior tested in rats on the 12th day of the abstinence period. Pretreatment with JMV2959 significantly reduced the expression of methamphetamine-induced CPP. Simultaneous administration of JMV2959 with methamphetamine during the conditioning period significantly reduced the methamphetamine-CPP. Our results encourage further research of the ghrelin antagonism as a potential new pharmacological tool for methamphetamine addiction treatment.

• MeSH
• analýza rozptylu MeSH
• autoaplikace MeSH
• časové faktory MeSH
• glycin aplikace a dávkování   analogy a deriváty   farmakologie   MeSH
• intravenózní podání MeSH
• methamfetamin aplikace a dávkování   farmakologie   MeSH
• podmiňování (psychologie) účinky léků   MeSH
• potkani Wistar MeSH
• prostorové chování účinky léků   MeSH
• receptory ghrelinu antagonisté a inhibitory   metabolismus   MeSH
• stimulanty centrálního nervového systému aplikace a dávkování   farmakologie   MeSH
• tělesná hmotnost účinky léků   MeSH
• triazoly aplikace a dávkování   farmakologie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH