OBJECTIVE There is growing evidence that uridine may act as an endogenous neuromodulator with a potential signaling role in the central nervous system in addition to its function in pyrimidine metabolism.We previously...OBJECTIVE There is growing evidence that uridine may act as an endogenous neuromodulator with a potential signaling role in the central nervous system in addition to its function in pyrimidine metabolism.We previously found that acute morphine treatment significantly increased uridine release in the dorsal striatum of mice,while the mechanism involved in morphine-induced uridine release and the role of uridine in morphine-induced neurobehavioral changes have not been understood.METHODS Uridine release in the dorsal striatum of mice was assessed by in vivo microdialysis coupled with high performance liquid chromatography(HPLC) after morphine treatment.Western blotting and immunofluorescence were used to evaluate the expression of uridine-related proteins.Morphine-induced neurobehavioral changes were assessed by locomotor activity,behavioral sensitization and conditioned place preference(CPP)test.The expression of NT5E,an extracellular enzyme involved in formation of nucleosides,including uridine,was specifically knocked down in the dorsal striatum of mice using adeno-associated virus(AAV)-mediated short hairpin RNA(shRNA).RESULTS Both acute and chronic morphine administration significantly increased uridine release in the dorsal striatum,and this was associated with upregulation of NT5E but not other uridine-related proteins.Inhibition of NT5E with APCP or shRNA markedly inhibited morphine-induced uridine release in the dorsal striatum and related neurobehavioral changes,including hyperlocomotor activity,behavioral sensitization and CPP.CONCLUSION The present study increases our understanding of the contribution of NT5E in regulating morphine-induced neurobehavioral changes,at least as related to uridine,and suggests that NT5E may be a novel therapeutic target to manage morphine abuse.展开更多
OBJECTIVE Cue-induced drug craving progressively increase after prolong abstinence in animal and human beings.A behavioral phenomenon termed incubation of drug craving is considered as a key reason for drug relapse,bu...OBJECTIVE Cue-induced drug craving progressively increase after prolong abstinence in animal and human beings.A behavioral phenomenon termed incubation of drug craving is considered as a key reason for drug relapse,but the transcriptional mechanisms that contribute to this incubation are unknown.It has been demonstrated that circular RNAs(circR NAs),act as miR NA sponges,play important roles in the regulation of gene expression and the pathogenesis of disease.The present study aims to explore the transcriptional profiles associated with incubation of morphine craving in nucleus accumbens(NAc),an important brain area previously implicated in drug seeking.METHODS The animal model of the incubation of drug craving was induced by CPP paradigms with six morphine(5 mg·kg-1) injections and 14 d drug abstinence in mice.The brain tissues of NAc were collected after the behavioral tests for circRNA-sequencing by Illumina Hiseq X sequencer.We identified differentially expressed genes(DEGs) by qRT-PCR and used bioinformatics methods for further function analysis.RESULTS The progressive increase of CPP scores during the 14 d drug abstinence indicated the establishment of animal model.The data of circRNA-sequencing reported that 16 circRNAs were significantly altered after 28 d drug abstinence in NAc of morphine treated mice(FC≥2 and P<0.05).Among those circRNAs,9 were significantly up-regulated,while 7 were down-regulated.Furthermore,we subsequently tested circRNAs expression using quantitative real-time PCR,and the consistent data were obtained.The results of KEGG pathway analysis indicated that these genes were enriched for several biological processes,including RNA transport,protein ubiquitination and histone methylation,etc.CONCLUSION These findings provide a unique resource of gene expression data for future studies examining transcriptional mechanisms in NAc that mediate opioids seeking after prolonged withdrawal.展开更多
OBJECTIVE Cognitive inflexibility plays a critical role in the compulsive drug taking,a central characteristic of drug addictions,yet its underlying neurochemical mechanisms are not well understood.The present study e...OBJECTIVE Cognitive inflexibility plays a critical role in the compulsive drug taking,a central characteristic of drug addictions,yet its underlying neurochemical mechanisms are not well understood.The present study examined the impact of morphine withdrawal on reversal learning.METHODS Reversal learning was tested in a four-choices digging task.Some brain tissues were harvested 2 h after the behavioral experiment for the further measurement.RESULTS We found that after long-term abstinence for a month from chronic morphine exposure,mice exhibited a profound reversal learning deficit.We further found that dopamine D2 receptor(D2R)system in the frontal-striatal circuit is significantly down-regulated,at both receptor and downstream signals levels.Subsequent pharmacological experiments demonstrated that aripiprazole,a D2R partial agonist,prevented the D2R downregulation and rescued the reversal learning deficit.CONCLUSION Together,our findings provide valuable insights into the causal relationship between D2R system in the frontal-striatal circuit and the cognitive inflexibility caused by abused drugs and offer a promising possibility of an effective therapeutic intervention for drug addictions.展开更多
Background and Aim Drug-induced sensitization in the mesocorticolimbic systems has been thought to play an important role in certain aspects of drug addiction, including the important function of drug-associated cues ...Background and Aim Drug-induced sensitization in the mesocorticolimbic systems has been thought to play an important role in certain aspects of drug addiction, including the important function of drug-associated cues and environments in mediating drug-seeking behaviors. Our previous studies have identified a role of heat shock protein 70 （Hsp70） in the development of a single exposure morphine-induced behavioral sensitization. Methods The present study investigated the effect of environment on the expression of behavioral sensitization in- duced by a single morphine exposure, and associated Hsp70 levels. Results Our results showed that expression of single exposure morphine-induced behavioral sensitization was accompanied by a significant increase of Hsp70 ex- mice administered morphine in an unpaired fashion failed pression in the nucleus accumbens （NAc）. In contrast, to exhibit behavioral sensitization or higher Hsp70 expression. Additionally, by using a habituation process before we found that there was a transition from conditioned hyperactivity to be- challenge to remove conditioned response, havioral sensitization, the former of which was not accompanied by an increased expression of Hsp70. Conclusions Together, these results suggest that behavioral sensitization induced by a single morphine exposure in mice exhib- its context- and time-dependent patterns with environmental context functioning probably via an inhibitory condition- ing mechanism. Alteration of Hsp70 expression in NAc may represent a neurobiological sensitization mechanism mediating context- and time-dependent behavioral sensitization.展开更多
OBJECTIVE Phosphoinositide 3-kinase(PI3K) activation was reported to participate in the development of effect of some drugs,such as morphine and cocaine dependence.We previous found nischarin is associated with the ac...OBJECTIVE Phosphoinositide 3-kinase(PI3K) activation was reported to participate in the development of effect of some drugs,such as morphine and cocaine dependence.We previous found nischarin is associated with the activation of PI3K.It is our great interest to investigate the involvement of nischarin in PI3K dependent modulation of morphine versus cocaine dependence.METHODS In order to study the role of nischarin in drug dependence and tolerance,nischarin knockout mice were used for our research.Effect of psychological dependence was studied by conditioned place preference(CPP),and the effect of physical dependence was tested by naloxone-precipitated withdrawal signs.Some brain tissues were harvested 24 h after the behavioral experiment for the further measurement.RESULTS PI3K specific inhibitor LY294002 significantly blocked the acquisition of morphine-induced CPP in wild-type mice,but had no effect on its expression.In comparison,LY294002 failed to block the acquisition of cocaine-induced CPP but inhibited the expression.Furthermore,we found naloxoneprecipitated withdrawal signs in the morphine dependent mice was inhibited by LY294002.Nischarin knockout in mice could abolish the effect of LY294002 on blocking the effects of morphine,but had no effect on cocaine.CONCLUSION PI3K activation is involved in the different phases of morphine and cocaine dependence,and nischarin plays an important role in the process.展开更多
OBJECTIVE To investigate the effects of heat shock protein 70(Hsp70)in the development as well as expression of morphine induced conditioned place preference(CPP)in rats using Hsp70 inhibitors.METHODS The unbi⁃ased pr...OBJECTIVE To investigate the effects of heat shock protein 70(Hsp70)in the development as well as expression of morphine induced conditioned place preference(CPP)in rats using Hsp70 inhibitors.METHODS The unbi⁃ased procedures of CPP lasted for 7 d and included three phases:preconditioning(D1-D3),conditioning(D4-D6,6 sessions)and test(D7).Here,morphine 5 mg·kg-1 injected in a subcuta⁃neous(sc)manner can induce significant place preference.Inhibitors of Hsp70 were injected into the right lateral ventricle during either the condi⁃tioning phase or the test phase separately.Fur⁃thermore,the expression of Hsp70 in certain areas of the mesocorticolimbic system was also studied following the intervention of N-formyl-3,4-methylenedioxybenzylidine-γ-butyrolactam(KNK437),a transcriptional inhibitor of Hsp70.RESULTS Pifithrin-μ(PES),a selective functional inhibitor acting on the substrate binding domain(SBD)of Hsp70,dose-dependently suppressed both the acquisition and expression of morphine-induced CPP.Similar function was observed after the intracerebroventricular injection(icv)of KNK437.The other functional inhibitor methy⁃lene blue,targeting the nucleotide-binding area,showed a significant tendency of inhibitory phar⁃macological effect on the expressional and devel⁃opment phases of morphine-induced CPP.Following the interventions of KNK437,we found that the level of Hsp70 was significantly decreased in the NAcs both in the acquisition and expres⁃sion of morphine induced CPP.CONCLUSION Hsp70 in NAcs plays a critical role in mediating the psychological dependence induced by morphine.展开更多
A rapid method for the determination of morphine-type drugs in urine was established by SPE/GC-MS,and was applied in the real samples with satisfactory results.
Aim Aconitine and its structurally-related diterpenoid alkaloids have been shown to interact differential- ly with neuronal voltage-dependent sodium channels and be responsible for their analgesia and toxicity. Bulley...Aim Aconitine and its structurally-related diterpenoid alkaloids have been shown to interact differential- ly with neuronal voltage-dependent sodium channels and be responsible for their analgesia and toxicity. Bulleya- conitine A （ BAA or BLA） is an aconitine analog and has been prescribed for the management of pain. The present study aimed to evaluate the inhibitory effects of BAA on pain hypersensitivity and morphine anti-nociceptive toler- ance, and explore whether the release of dynorphin A from spinal microglia was associated with its mechanism of actions. Methods Rat models of neuropathic pain, formalin test and bone cancer pain were used, and spinal dynorphin A level and expression were measured. Sample size of animals was six in each study group. Resultes A single intrathecal or subcutaneous （but not intraventricular or local） injection of BAA blocked spinal nerve liga- tion-induced painful neuropathy, bone cancer-induced pain and formalin-induced hyperalgesia by 60% - 100% with the ED50 values of 94 - 126 ng/rat （intrathecal） and 42 - 59 μg · kg^-1 （ subcutaneous）, respectively. Follow- ing chronic treatment, BAA did not induce either self-tolerance to anti-nociception or cross-tolerance to morphine anti-nociception, and completely prevented morphine tolerance. Spinal BAA anti-nociception, but not neurotoxici- ty, was completely blocked by the specific microglial inhibitor minocycline. In a minocycline-sensitive and lido- BAA stimulated the release of dynorphin A from the spinal cord, and the caine- or ropivacaine-insensitive manner, primary culture of microglia but not from neurons or astrocytes. The blockade effects of BAA on nociception and morphine tolerance were completely blocked by the specific dynorphin A antiserum and/or K-opioid receptor antago- nist. Conclusions Our results demonstrated that BAA eliminated pain hypersensitivity and morphine tolerance through the direct stimulation of dynorphin A release from spinal microglia, which was not dependent on the interac- tions with sodium channels.展开更多
多层Morphin算法扩展了对未知环境的预测范围,克服了传统Morphin算法搜索轨迹不灵活的缺点,但每个搜索节点生成的搜索弧数目固定,搜索和评估所花费的时间随着搜索层数的增多呈指数阶增加。针对该问题,提出了一种可变搜索弧Morphin算法(v...多层Morphin算法扩展了对未知环境的预测范围,克服了传统Morphin算法搜索轨迹不灵活的缺点,但每个搜索节点生成的搜索弧数目固定,搜索和评估所花费的时间随着搜索层数的增多呈指数阶增加。针对该问题,提出了一种可变搜索弧Morphin算法(variable search arc of Morphin,VSA-Morphin)。调整每层搜索节点生成的搜索弧数目,使之不再固定,而是随着层数增加而减少,从而缩短搜索和评估时间。利用MATLAB仿真测试表明,多层VSA-Morphin算法与多层Morphin算法所规划的路径基本一致,但运行时间却相对更少,从而验证了多层VSA-Morphin算法的有效性和正确性。展开更多
基金National Natural Science Foundation of China(81373383).
文摘OBJECTIVE There is growing evidence that uridine may act as an endogenous neuromodulator with a potential signaling role in the central nervous system in addition to its function in pyrimidine metabolism.We previously found that acute morphine treatment significantly increased uridine release in the dorsal striatum of mice,while the mechanism involved in morphine-induced uridine release and the role of uridine in morphine-induced neurobehavioral changes have not been understood.METHODS Uridine release in the dorsal striatum of mice was assessed by in vivo microdialysis coupled with high performance liquid chromatography(HPLC) after morphine treatment.Western blotting and immunofluorescence were used to evaluate the expression of uridine-related proteins.Morphine-induced neurobehavioral changes were assessed by locomotor activity,behavioral sensitization and conditioned place preference(CPP)test.The expression of NT5E,an extracellular enzyme involved in formation of nucleosides,including uridine,was specifically knocked down in the dorsal striatum of mice using adeno-associated virus(AAV)-mediated short hairpin RNA(shRNA).RESULTS Both acute and chronic morphine administration significantly increased uridine release in the dorsal striatum,and this was associated with upregulation of NT5E but not other uridine-related proteins.Inhibition of NT5E with APCP or shRNA markedly inhibited morphine-induced uridine release in the dorsal striatum and related neurobehavioral changes,including hyperlocomotor activity,behavioral sensitization and CPP.CONCLUSION The present study increases our understanding of the contribution of NT5E in regulating morphine-induced neurobehavioral changes,at least as related to uridine,and suggests that NT5E may be a novel therapeutic target to manage morphine abuse.
基金Natural Science Foundation of Hebei Province(H2018206166)National Natural Science Foundation of China (81871524).
文摘OBJECTIVE Cue-induced drug craving progressively increase after prolong abstinence in animal and human beings.A behavioral phenomenon termed incubation of drug craving is considered as a key reason for drug relapse,but the transcriptional mechanisms that contribute to this incubation are unknown.It has been demonstrated that circular RNAs(circR NAs),act as miR NA sponges,play important roles in the regulation of gene expression and the pathogenesis of disease.The present study aims to explore the transcriptional profiles associated with incubation of morphine craving in nucleus accumbens(NAc),an important brain area previously implicated in drug seeking.METHODS The animal model of the incubation of drug craving was induced by CPP paradigms with six morphine(5 mg·kg-1) injections and 14 d drug abstinence in mice.The brain tissues of NAc were collected after the behavioral tests for circRNA-sequencing by Illumina Hiseq X sequencer.We identified differentially expressed genes(DEGs) by qRT-PCR and used bioinformatics methods for further function analysis.RESULTS The progressive increase of CPP scores during the 14 d drug abstinence indicated the establishment of animal model.The data of circRNA-sequencing reported that 16 circRNAs were significantly altered after 28 d drug abstinence in NAc of morphine treated mice(FC≥2 and P<0.05).Among those circRNAs,9 were significantly up-regulated,while 7 were down-regulated.Furthermore,we subsequently tested circRNAs expression using quantitative real-time PCR,and the consistent data were obtained.The results of KEGG pathway analysis indicated that these genes were enriched for several biological processes,including RNA transport,protein ubiquitination and histone methylation,etc.CONCLUSION These findings provide a unique resource of gene expression data for future studies examining transcriptional mechanisms in NAc that mediate opioids seeking after prolonged withdrawal.
文摘OBJECTIVE Cognitive inflexibility plays a critical role in the compulsive drug taking,a central characteristic of drug addictions,yet its underlying neurochemical mechanisms are not well understood.The present study examined the impact of morphine withdrawal on reversal learning.METHODS Reversal learning was tested in a four-choices digging task.Some brain tissues were harvested 2 h after the behavioral experiment for the further measurement.RESULTS We found that after long-term abstinence for a month from chronic morphine exposure,mice exhibited a profound reversal learning deficit.We further found that dopamine D2 receptor(D2R)system in the frontal-striatal circuit is significantly down-regulated,at both receptor and downstream signals levels.Subsequent pharmacological experiments demonstrated that aripiprazole,a D2R partial agonist,prevented the D2R downregulation and rescued the reversal learning deficit.CONCLUSION Together,our findings provide valuable insights into the causal relationship between D2R system in the frontal-striatal circuit and the cognitive inflexibility caused by abused drugs and offer a promising possibility of an effective therapeutic intervention for drug addictions.
文摘Background and Aim Drug-induced sensitization in the mesocorticolimbic systems has been thought to play an important role in certain aspects of drug addiction, including the important function of drug-associated cues and environments in mediating drug-seeking behaviors. Our previous studies have identified a role of heat shock protein 70 （Hsp70） in the development of a single exposure morphine-induced behavioral sensitization. Methods The present study investigated the effect of environment on the expression of behavioral sensitization in- duced by a single morphine exposure, and associated Hsp70 levels. Results Our results showed that expression of single exposure morphine-induced behavioral sensitization was accompanied by a significant increase of Hsp70 ex- mice administered morphine in an unpaired fashion failed pression in the nucleus accumbens （NAc）. In contrast, to exhibit behavioral sensitization or higher Hsp70 expression. Additionally, by using a habituation process before we found that there was a transition from conditioned hyperactivity to be- challenge to remove conditioned response, havioral sensitization, the former of which was not accompanied by an increased expression of Hsp70. Conclusions Together, these results suggest that behavioral sensitization induced by a single morphine exposure in mice exhib- its context- and time-dependent patterns with environmental context functioning probably via an inhibitory condition- ing mechanism. Alteration of Hsp70 expression in NAc may represent a neurobiological sensitization mechanism mediating context- and time-dependent behavioral sensitization.
基金National Natural Science Foundation of China (81673409).
文摘OBJECTIVE Phosphoinositide 3-kinase(PI3K) activation was reported to participate in the development of effect of some drugs,such as morphine and cocaine dependence.We previous found nischarin is associated with the activation of PI3K.It is our great interest to investigate the involvement of nischarin in PI3K dependent modulation of morphine versus cocaine dependence.METHODS In order to study the role of nischarin in drug dependence and tolerance,nischarin knockout mice were used for our research.Effect of psychological dependence was studied by conditioned place preference(CPP),and the effect of physical dependence was tested by naloxone-precipitated withdrawal signs.Some brain tissues were harvested 24 h after the behavioral experiment for the further measurement.RESULTS PI3K specific inhibitor LY294002 significantly blocked the acquisition of morphine-induced CPP in wild-type mice,but had no effect on its expression.In comparison,LY294002 failed to block the acquisition of cocaine-induced CPP but inhibited the expression.Furthermore,we found naloxoneprecipitated withdrawal signs in the morphine dependent mice was inhibited by LY294002.Nischarin knockout in mice could abolish the effect of LY294002 on blocking the effects of morphine,but had no effect on cocaine.CONCLUSION PI3K activation is involved in the different phases of morphine and cocaine dependence,and nischarin plays an important role in the process.
基金National Natural Science Foundation of China(81773705)。
文摘OBJECTIVE To investigate the effects of heat shock protein 70(Hsp70)in the development as well as expression of morphine induced conditioned place preference(CPP)in rats using Hsp70 inhibitors.METHODS The unbi⁃ased procedures of CPP lasted for 7 d and included three phases:preconditioning(D1-D3),conditioning(D4-D6,6 sessions)and test(D7).Here,morphine 5 mg·kg-1 injected in a subcuta⁃neous(sc)manner can induce significant place preference.Inhibitors of Hsp70 were injected into the right lateral ventricle during either the condi⁃tioning phase or the test phase separately.Fur⁃thermore,the expression of Hsp70 in certain areas of the mesocorticolimbic system was also studied following the intervention of N-formyl-3,4-methylenedioxybenzylidine-γ-butyrolactam(KNK437),a transcriptional inhibitor of Hsp70.RESULTS Pifithrin-μ(PES),a selective functional inhibitor acting on the substrate binding domain(SBD)of Hsp70,dose-dependently suppressed both the acquisition and expression of morphine-induced CPP.Similar function was observed after the intracerebroventricular injection(icv)of KNK437.The other functional inhibitor methy⁃lene blue,targeting the nucleotide-binding area,showed a significant tendency of inhibitory phar⁃macological effect on the expressional and devel⁃opment phases of morphine-induced CPP.Following the interventions of KNK437,we found that the level of Hsp70 was significantly decreased in the NAcs both in the acquisition and expres⁃sion of morphine induced CPP.CONCLUSION Hsp70 in NAcs plays a critical role in mediating the psychological dependence induced by morphine.
文摘A rapid method for the determination of morphine-type drugs in urine was established by SPE/GC-MS,and was applied in the real samples with satisfactory results.
基金Supported by the Key Research and Development Plan of Shandong Province(2018GGX106001)supported by the Natural Science Foundation of Shandong Province(ZR2017MEE066)Supported by the Science and Technology Plan of Shandong higher Education institutions(J16LB58)~~
文摘Aim Aconitine and its structurally-related diterpenoid alkaloids have been shown to interact differential- ly with neuronal voltage-dependent sodium channels and be responsible for their analgesia and toxicity. Bulleya- conitine A （ BAA or BLA） is an aconitine analog and has been prescribed for the management of pain. The present study aimed to evaluate the inhibitory effects of BAA on pain hypersensitivity and morphine anti-nociceptive toler- ance, and explore whether the release of dynorphin A from spinal microglia was associated with its mechanism of actions. Methods Rat models of neuropathic pain, formalin test and bone cancer pain were used, and spinal dynorphin A level and expression were measured. Sample size of animals was six in each study group. Resultes A single intrathecal or subcutaneous （but not intraventricular or local） injection of BAA blocked spinal nerve liga- tion-induced painful neuropathy, bone cancer-induced pain and formalin-induced hyperalgesia by 60% - 100% with the ED50 values of 94 - 126 ng/rat （intrathecal） and 42 - 59 μg · kg^-1 （ subcutaneous）, respectively. Follow- ing chronic treatment, BAA did not induce either self-tolerance to anti-nociception or cross-tolerance to morphine anti-nociception, and completely prevented morphine tolerance. Spinal BAA anti-nociception, but not neurotoxici- ty, was completely blocked by the specific microglial inhibitor minocycline. In a minocycline-sensitive and lido- BAA stimulated the release of dynorphin A from the spinal cord, and the caine- or ropivacaine-insensitive manner, primary culture of microglia but not from neurons or astrocytes. The blockade effects of BAA on nociception and morphine tolerance were completely blocked by the specific dynorphin A antiserum and/or K-opioid receptor antago- nist. Conclusions Our results demonstrated that BAA eliminated pain hypersensitivity and morphine tolerance through the direct stimulation of dynorphin A release from spinal microglia, which was not dependent on the interac- tions with sodium channels.
文摘多层Morphin算法扩展了对未知环境的预测范围,克服了传统Morphin算法搜索轨迹不灵活的缺点,但每个搜索节点生成的搜索弧数目固定,搜索和评估所花费的时间随着搜索层数的增多呈指数阶增加。针对该问题,提出了一种可变搜索弧Morphin算法(variable search arc of Morphin,VSA-Morphin)。调整每层搜索节点生成的搜索弧数目,使之不再固定,而是随着层数增加而减少,从而缩短搜索和评估时间。利用MATLAB仿真测试表明,多层VSA-Morphin算法与多层Morphin算法所规划的路径基本一致,但运行时间却相对更少,从而验证了多层VSA-Morphin算法的有效性和正确性。
