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Chronic ethanol consumption changes expression of microRNA in mouse brain
Abstracts / Neuroscience Research 71S (2011) e108–e415
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alterations in the tissue levels of monoamines and their metabolites in the cerebral cortex, the region of striatum and nucleus accumbens, and the region of thalamus and hypothalamus between mice with and without ISL pretreatment. Mice treated with ISL prior to METH (0.5 mg/kg) preconditioning showed a significant METH-induced CPP, similar to that observed in mice treated with vehicle prior to METH preconditioning. Total incidence of METH (10 mg/kg)-induced stereotypy was unaffected by pretreatment with ISL. These observations suggest that ISL selectively inhibits METH-induced hyperlocomotion in mice. Research fund: KAKENHI (21790254).
manner. Our previous study, METH did not induce behavioral sensitization in serotonin transporter knockout mice;therefore, the excess serotonin causes the attenuation of behavioral sensitization. Acute injection of METH (1 or 3 mg/kg,i.p.) resulted in elevated levels of extracellular serotonin in 5-HT1B +/− mice; therefore, METH-induced behavioral sensitization was significantly attenuated in 5-HT1B +/− mice but not in 5-HT1B −/− mice. Overall, monoaminergic systems via 5-HT1B receptors may play a key role in regulating METH-induced hyperlocomotor activity and behavioral sensitization. Research fund: This work was supported by Health Labour Sciences Research Grant.
doi:10.1016/j.neures.2011.07.1739
doi:10.1016/j.neures.2011.07.1741
P4-r19 Chronic ethanol consumption changes expression of microRNA in mouse brain
P4-r21 Dopamine antagonist induced-PSD protein reductions in the rat nucleus accumbens of after repeated cocaine administration
Keisuke Mizuo , Ryuichi Katada, Shunichiro Okazaki, Kenji Tateda, Satoshi Watanabe, Hiroshi Matsumoto Dept. of Legal Med. and Mol. Alcohol., Sapporo Med. Univ., Sch. of Med., Sapporo, Japan Alcoholism is a complex disorder resulting from multiple interaction between genetic, epigenetic and environmental factors. However, the pathogenesis has never been established. In the present study, we investigated whether chronic ethanol consumption can change expression of brainenriched microRNA miR-124 and miR-132 in mouse brain. Mice were treated with liquid diet containing ethanol for 10 days. Using the escalating ethanol dosage schedule, the mice were fed the ethanol diet as follows: 1st day: 1 w/v%; 2nd and 3rd day: 3 w/v%; 4th and 5th day: 4 w/v% and from the 6th to 10th day: 5 w/v% ethanol diet, respectively. The pair-fed control mice were given the same volume of ethanol-free liquid diet with glucose substituted in isocaloric quantities for ethanol. First, we observed withdrawal signs after discontinuation of ethanol treatment. The mice chronically treated with ethanol revealed severe withdrawal signs. Under these conditions, the mice were killed by decapitation and the limbic forebrain (containing nucleus accumbens), lower midbrain (containing ventral tegmental area), amygdala and hippocampus were dissected. Northern blotting analysis for detection of microRNAs in the brain was performed. Here we show that the expression of miR-124 was significantly increased in limbic forebrain and lower midbrain following chronic treatment of ethanol, whereas there was no change in the amygdala and hippocampus. Moreover, miR-132 was not detected in all brain regions. It is widely known that mesolimbic dopaminergic system is implicated in the development of dependence of abused drugs. Taken together, these findings suggest that changes in the expression of miR-124 in mesolimbic dopaminergic system may contribute to the development of ethanol dependence. Research fund: KAKENHI 21790611. doi:10.1016/j.neures.2011.07.1740
P4-r20 Methamphetamine-induced behavioral sensitization in 5-HT1B-KO mice
Shigenobu Toda , Sakurako Kosugi, Yoshio Iguchi, Yoshio Minabe Department of Psychiatry and Neurobiology, Kanazawa Univ., Kanazawa, Japan Based on the pathological data from the studies of Parkinsonism, it is proposed that dopaminergic tone is involved in maintaining spine morphology in the striatum, however, the precise molecular mechanisms have not been revealed yet. Since dopaminergic tone is elevated in the nucleus accumbens (NAc) of rats after repeated cocaine administration, we examined the significance of dopaminergic tone in maintaining the components of postsynaptic density (PSD) in medium spiny neurons, by employing dopamine D1/D2 antagonist, flupenthixol (Flu). We found that Flu decreased many PSD proteins, including actin, PSD-95, GluR1, GluR2 and NR2A in PSD fraction of the NAc in repeatedly cocaine treated rats in 30 min, but not in control rats. Surprisingly, the ratio of PSD proteins to extrasynaptic membrane (ESM) proteins were elevated at the same time, suggesting that Flu induced protein influx from outside PSD so that the original PSD proteins were excluded from PSD and/or diluted by non-PSD proteins. A similar observation was obtained from rats after repeated cocaine administration; 2h after a cocaine challenge, most of PSD proteins were reduced in PSD fraction, whereas PSD/ESM ratio was elevated. It is possible that Flu or a cocaine challenge induced actin depolymerization, which results in the collapse of PSD proteins. Supporting this idea, actin severing/depolymerizing factor, cofilin, was induced in PSD fraction by a cocaine challenge. However, our investigation in spine morphology suggested that actin depolymerization may not be the sole determinant. A current model of regulation in spine morphology during induction of longterm potentiation (LTP) indicates a restriction of protein diffusion between spines and dendrites for promoting compartmentalization of spine heads (Bloodgood and Sabatini, 2005). Based on this model, we propose that our observation may be reflecting something opposite process to LTP, and that dopamine D2 signaling may be involved in this process. Research fund: KAKENHI (22591257 and 22791114) and Takeda Science Foundation. doi:10.1016/j.neures.2011.07.1742
Yuki Moriya , Kana Ishihara, Yoshiyuki Kasahara, Ichiro Sora Grad. School of Med., Dept. of Neuroscience, Division of Psychobiology, Tohoku Univ Background: Methamphetamine (METH), a psychostimulant drug causes euphoria and locomotor hyperactivity by acting on the mesolimbic dopamine pathway, thus making it tends to abuse and addiction. Behavior sensitization, a phenomenon involved increasing behavioral response to repeated exposure to a psychostimulant, persists many months after the last administration. In our previous study, the behavioral sensitization was enhanced with the homozygous 5-HT1B receptors knockout (5-HT1B −/−) mice rather than the wild-type mice; however, it was attenuated with the heterozygous 5-HT1B-KO (5-HT1B +/−) mice. Purpose: In our current experiment, our objective was to investigate the extracellular monoamine levels using in vivo microdialysis in 5-HT1B-KO mice after single administration of METH. Results: There were significant differences in extracellular monoamine levels between METH- and saline-treated mice. The METH-induced increase in striatal dopamine levels in 5-HT1B −/−mice was significantly higher than other genotype mice. Moreover, a tendency to a higher level of striatal serotonin was observed in 5-HT1B +/− mice at 1 and 3 mg/kg METH. Discussion: These results show that a gene dose-dependent increase in extracellular dopamine levels was observed in the striatum. Consequently, enhanced striatal extracellular dopamine levels contributed to the expression of behavioral sensitization in 5-HT1B −/− mice in the dose-dependent
P4-s01 Glutamate-independent effects of N-acetylcysteine in synaptic protein turnover in the rat nucleus accumbens after repeated cocaine administration Sakurako Kosugi , Yoshio Iguchi, Yoshio Minabe, Shigenobu Toda Department of Psy. and Neurobi., Grad. Sch. of Med., Kanazawa University, Kanazawa, Japan Drug addiction causes serious public health issue, however, there are few therapeutic approaches available to date. Recently, N-acetylcysteine (NAC), known as cysteine precursor used against oxidative stress, was emerged as a potential candidate to treat cocaine addiction. In the nucleus accumbens of repeatedly cocaine-treated animals, the level of extracellular glutamate is significantly downregulated, which results in enhanced phasic glutamate release and cocaine-seeking behaviors. NAC restores the level of extracellular glutamate by activating system Xc-, a sodium-independent antiporter exchanging extracellular cystine with intracellular glutamate. Besides, NAC restores blunted long-term depression in the nucleus accumbens of chronic cocaine-treated animals. To address the molecular mechanisms underlying plasticity repairing by NAC, we investigated the effects of NAC on the levels of major synaptic proteins in the whole lysates of the rat nucleus accumbens. We found that many synaptic proteins, such as actin, PSD-95, GluR1, GluR2, NR2A and gephyrin, were significantly reduced 2.5 hr after NAC treatment in chronic cocaine-treated animals, but not in control animals. It is likely that these reductions were due to NAC-induced protein degradation, since NAC
e397
alterations in the tissue levels of monoamines and their metabolites in the cerebral cortex, the region of striatum and nucleus accumbens, and the region of thalamus and hypothalamus between mice with and without ISL pretreatment. Mice treated with ISL prior to METH (0.5 mg/kg) preconditioning showed a significant METH-induced CPP, similar to that observed in mice treated with vehicle prior to METH preconditioning. Total incidence of METH (10 mg/kg)-induced stereotypy was unaffected by pretreatment with ISL. These observations suggest that ISL selectively inhibits METH-induced hyperlocomotion in mice. Research fund: KAKENHI (21790254).
manner. Our previous study, METH did not induce behavioral sensitization in serotonin transporter knockout mice;therefore, the excess serotonin causes the attenuation of behavioral sensitization. Acute injection of METH (1 or 3 mg/kg,i.p.) resulted in elevated levels of extracellular serotonin in 5-HT1B +/− mice; therefore, METH-induced behavioral sensitization was significantly attenuated in 5-HT1B +/− mice but not in 5-HT1B −/− mice. Overall, monoaminergic systems via 5-HT1B receptors may play a key role in regulating METH-induced hyperlocomotor activity and behavioral sensitization. Research fund: This work was supported by Health Labour Sciences Research Grant.
doi:10.1016/j.neures.2011.07.1739
doi:10.1016/j.neures.2011.07.1741
P4-r19 Chronic ethanol consumption changes expression of microRNA in mouse brain
P4-r21 Dopamine antagonist induced-PSD protein reductions in the rat nucleus accumbens of after repeated cocaine administration
Keisuke Mizuo , Ryuichi Katada, Shunichiro Okazaki, Kenji Tateda, Satoshi Watanabe, Hiroshi Matsumoto Dept. of Legal Med. and Mol. Alcohol., Sapporo Med. Univ., Sch. of Med., Sapporo, Japan Alcoholism is a complex disorder resulting from multiple interaction between genetic, epigenetic and environmental factors. However, the pathogenesis has never been established. In the present study, we investigated whether chronic ethanol consumption can change expression of brainenriched microRNA miR-124 and miR-132 in mouse brain. Mice were treated with liquid diet containing ethanol for 10 days. Using the escalating ethanol dosage schedule, the mice were fed the ethanol diet as follows: 1st day: 1 w/v%; 2nd and 3rd day: 3 w/v%; 4th and 5th day: 4 w/v% and from the 6th to 10th day: 5 w/v% ethanol diet, respectively. The pair-fed control mice were given the same volume of ethanol-free liquid diet with glucose substituted in isocaloric quantities for ethanol. First, we observed withdrawal signs after discontinuation of ethanol treatment. The mice chronically treated with ethanol revealed severe withdrawal signs. Under these conditions, the mice were killed by decapitation and the limbic forebrain (containing nucleus accumbens), lower midbrain (containing ventral tegmental area), amygdala and hippocampus were dissected. Northern blotting analysis for detection of microRNAs in the brain was performed. Here we show that the expression of miR-124 was significantly increased in limbic forebrain and lower midbrain following chronic treatment of ethanol, whereas there was no change in the amygdala and hippocampus. Moreover, miR-132 was not detected in all brain regions. It is widely known that mesolimbic dopaminergic system is implicated in the development of dependence of abused drugs. Taken together, these findings suggest that changes in the expression of miR-124 in mesolimbic dopaminergic system may contribute to the development of ethanol dependence. Research fund: KAKENHI 21790611. doi:10.1016/j.neures.2011.07.1740
P4-r20 Methamphetamine-induced behavioral sensitization in 5-HT1B-KO mice
Shigenobu Toda , Sakurako Kosugi, Yoshio Iguchi, Yoshio Minabe Department of Psychiatry and Neurobiology, Kanazawa Univ., Kanazawa, Japan Based on the pathological data from the studies of Parkinsonism, it is proposed that dopaminergic tone is involved in maintaining spine morphology in the striatum, however, the precise molecular mechanisms have not been revealed yet. Since dopaminergic tone is elevated in the nucleus accumbens (NAc) of rats after repeated cocaine administration, we examined the significance of dopaminergic tone in maintaining the components of postsynaptic density (PSD) in medium spiny neurons, by employing dopamine D1/D2 antagonist, flupenthixol (Flu). We found that Flu decreased many PSD proteins, including actin, PSD-95, GluR1, GluR2 and NR2A in PSD fraction of the NAc in repeatedly cocaine treated rats in 30 min, but not in control rats. Surprisingly, the ratio of PSD proteins to extrasynaptic membrane (ESM) proteins were elevated at the same time, suggesting that Flu induced protein influx from outside PSD so that the original PSD proteins were excluded from PSD and/or diluted by non-PSD proteins. A similar observation was obtained from rats after repeated cocaine administration; 2h after a cocaine challenge, most of PSD proteins were reduced in PSD fraction, whereas PSD/ESM ratio was elevated. It is possible that Flu or a cocaine challenge induced actin depolymerization, which results in the collapse of PSD proteins. Supporting this idea, actin severing/depolymerizing factor, cofilin, was induced in PSD fraction by a cocaine challenge. However, our investigation in spine morphology suggested that actin depolymerization may not be the sole determinant. A current model of regulation in spine morphology during induction of longterm potentiation (LTP) indicates a restriction of protein diffusion between spines and dendrites for promoting compartmentalization of spine heads (Bloodgood and Sabatini, 2005). Based on this model, we propose that our observation may be reflecting something opposite process to LTP, and that dopamine D2 signaling may be involved in this process. Research fund: KAKENHI (22591257 and 22791114) and Takeda Science Foundation. doi:10.1016/j.neures.2011.07.1742
Yuki Moriya , Kana Ishihara, Yoshiyuki Kasahara, Ichiro Sora Grad. School of Med., Dept. of Neuroscience, Division of Psychobiology, Tohoku Univ Background: Methamphetamine (METH), a psychostimulant drug causes euphoria and locomotor hyperactivity by acting on the mesolimbic dopamine pathway, thus making it tends to abuse and addiction. Behavior sensitization, a phenomenon involved increasing behavioral response to repeated exposure to a psychostimulant, persists many months after the last administration. In our previous study, the behavioral sensitization was enhanced with the homozygous 5-HT1B receptors knockout (5-HT1B −/−) mice rather than the wild-type mice; however, it was attenuated with the heterozygous 5-HT1B-KO (5-HT1B +/−) mice. Purpose: In our current experiment, our objective was to investigate the extracellular monoamine levels using in vivo microdialysis in 5-HT1B-KO mice after single administration of METH. Results: There were significant differences in extracellular monoamine levels between METH- and saline-treated mice. The METH-induced increase in striatal dopamine levels in 5-HT1B −/−mice was significantly higher than other genotype mice. Moreover, a tendency to a higher level of striatal serotonin was observed in 5-HT1B +/− mice at 1 and 3 mg/kg METH. Discussion: These results show that a gene dose-dependent increase in extracellular dopamine levels was observed in the striatum. Consequently, enhanced striatal extracellular dopamine levels contributed to the expression of behavioral sensitization in 5-HT1B −/− mice in the dose-dependent
P4-s01 Glutamate-independent effects of N-acetylcysteine in synaptic protein turnover in the rat nucleus accumbens after repeated cocaine administration Sakurako Kosugi , Yoshio Iguchi, Yoshio Minabe, Shigenobu Toda Department of Psy. and Neurobi., Grad. Sch. of Med., Kanazawa University, Kanazawa, Japan Drug addiction causes serious public health issue, however, there are few therapeutic approaches available to date. Recently, N-acetylcysteine (NAC), known as cysteine precursor used against oxidative stress, was emerged as a potential candidate to treat cocaine addiction. In the nucleus accumbens of repeatedly cocaine-treated animals, the level of extracellular glutamate is significantly downregulated, which results in enhanced phasic glutamate release and cocaine-seeking behaviors. NAC restores the level of extracellular glutamate by activating system Xc-, a sodium-independent antiporter exchanging extracellular cystine with intracellular glutamate. Besides, NAC restores blunted long-term depression in the nucleus accumbens of chronic cocaine-treated animals. To address the molecular mechanisms underlying plasticity repairing by NAC, we investigated the effects of NAC on the levels of major synaptic proteins in the whole lysates of the rat nucleus accumbens. We found that many synaptic proteins, such as actin, PSD-95, GluR1, GluR2, NR2A and gephyrin, were significantly reduced 2.5 hr after NAC treatment in chronic cocaine-treated animals, but not in control animals. It is likely that these reductions were due to NAC-induced protein degradation, since NAC