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Effects of reversible inactivation of the ventral tegmental area on the expression of morphine-induced conditioned place preference in the rat
Abstracts prenatal stress inhibits the dendritic maturation of GCs by decreasing the MR expression. doi:10.1016/j.neures.2009.09.1450
P3-o16 Colchicine-induced dentate granule cell loss impairs behavioral effects of acute but not chronic antidepressants Daisuke Miyamoto, Minoru Iijima, Hiroshi Nomura, Haruka Yamamoto, Norio Matsuki Lab. Chem. Pharmacol., Grad. Sch. Pharm., Univ. Tokyo, Japan It is controversial that adult-generated granule cells in the dentate gyrus are the target of antidepressants. To test whether the dentate granule cells are required for the behavioral effects of acute and chronic antidepressants treatments, we selectively ablated dentate granule cells by intrahippocampal colchicine injection. Acute treatments of desipramine or fluoxetine (20 mg/kg, i.p., 3 times) decreased the immobility in the forced swimming test (FST) in control rats, but not in colchicine injected rats. Chronic treatments of desipramine or fluoxetine (10 mg/kg, p.o., 28days) decreased the immobility in FST and the latency to feed in novelty suppressed feeding test in both control and colchicine injected rats. We confirmed the decrease of proliferating cells in the subgranular zone by immunohistochemistry for BrdU in the colchicine injected rats and the decrease was not reversed by chronic antidepressant. These findings suggest that the dentate granule cells are not essential for the behavioral effects of chronic antidepressants. doi:10.1016/j.neures.2009.09.1451
S255
P3-o19 Intense exercise-induced depression-like behavior is improved by imipramine in mice Kaori Nagasaka, Yasushi Kanai, Akiko Muroyama, Yasuhide Mitsumoto Dept. of Alternative Med. and Exp. Therapeutics, Faculty of Pharmaceutical Sciences, Hokuriku University, Japan Exercise training has been well recognized as an important strategy to counteract the risk factors related to neurodegenerative and psychiatric disorders, such as depression and anxiety. Some exercise can be also injurious to tissues. In fact, this kind of exercise generates high levels of reactive oxygen species, leading to oxidative damage in brain. In this study, we showed that intense exercise (IE, run on treadmill at a speed of 10 m/min for 30 min each day for 1 week) led to depression-like behavior in mice using a behavioral paradigm of forced swimming test (FST). Imipramine (10 mg/kg, i.p.) completely reversed the increased immobility time in the FST in the exercised mice. Locomotor activity was not influenced by IE. Theses results indicate that IE certainly becomes a physical stress, which leads to depression-like behavior. IE could induce the alteration of brain environment, because the emotional abnormality was improved by a known antidepressant. doi:10.1016/j.neures.2009.09.1454
P3-o20 Lowering barometric pressure aggravates depression-like behavior in rats Jun Sato, Kanoko Fukaya, Hiroyuki Mizoguchi
anxiety/
Res. Inst. Environ. Med., Nagoya Univ., Nagoya, Japan
P3-o17 Diesel exhaust particles during fetal period increase anxietylike behavior Akira Sato 1 , Satoshi Yokota 1 , Keisuke Mizuo 2 , Nozomu Moriya 1 , Isao Sugawara 3 , Ken Takeda 1 1 Lab. of Hygienic Chemistry, Grad. Sch. of Medicine, Tokyo Univ. of Sci., Japan; 2 Research Center for Health Science of Nanoparticles, Tokyo University of Science, Japan; 3 The Research Institute of Tuberculosis, Japan
Diesel exhaust (DE) is a major contributor to air pollution. It has been reported that DE causes various adverse health effects; however, the influence of DE on the brain has yet to be clarified. We investigated the effects of exposure to diesel exhaust particles (DEP) during fetal period on the central nervous system in mice using several behavioral tests. In the elevated plus maze test, DEP exposure significantly increased the number of entries into the open arms of the maze, but there was no difference between DEP administered and control mice in other tests. That mice administered with DEP during the fetal period display increased anxiety-like behavior suggests that DEP exposure may lead them to more easily experience anxiety. doi:10.1016/j.neures.2009.09.1452
P3-o18 Influence of chronic cerebral hypoperfusion on depressive phenotypes Kaichi Yoshizaki 1,2 , Yoshinobu Hara 1 , Hideaki Wakita 2 , Noriko Osumi 1 1
Div. Dev. Neurosci., Univ. of Tohoku, Miyagi, Japan; Nat. Inst. for Longevi. Sci., Aichi, Japan
2
Vasc. Dement. Res.,
Although previous studies have demonstrated that hypoperfusion in the prefrontal cortex and anterior cingulate gyrus is involved in the pathophysiology of depression, the etiology and pathologic mechanisms of depression by cerebral hypoperfusion remain unclear. Here we attempted to investigate the influence of chronic cerebral hypopefusion on depressive phenotypes. Mice (C57BL6/J, male, 12-week-old) subjected to permanent right unilateral common carotid artery occlusion (UCCAO) were investigated for depression-like behaviors by open field test (OFT), novel suppressed feeding test (NSFT) and sucrose consumption test (SCT) at 1 and 4 weeks after the surgery. The results showed that mice subjected to right UCCAO did not exhibit any differences in OFT, NSFT and SCT, although these right UCCAO mice exhibit impaired cognitive functions (Yoshizaki et al., 2008). Now we assess the depression-like behaviors in mice subjected to left UCCAO to investigate the influence of unilateral cerebral hypoperfusion as an etiology of the depressive phenotypes. doi:10.1016/j.neures.2009.09.1453
Weather changes have been known to influence the condition among patients with mood disorders. However, there is no relevant animal model for testing the influence of climatic factors on emotional impairment. Firstly we examined the effect of lowering barometric pressure (LP) on the immobility time (IT) in the forced swim test (FST) in rats, which is considered as an index of learned helplessness. When the rats were exposed to daily repeated FST, the IT gradually increased. This increment was inhibited by chronic administration of antidepressant (imipramine), suggesting that the immobility is anxiety/depression-like behavior. LP (27 hPa below the atmospheric pressure) increased IT in rats submitted to the repeated FST. Secondarily we examined the effect of daily LP exposure on the maintenance of IT after withdrawal from 6-day FST. When the rats were challenged in FST under LP condition on day 14 after the withdrawal, IT was significantly longer than those in non-conditioned rats. The current findings demonstrate that LP in the range of natural weather changes augmented the anxiety/depression-like behavior in rats. doi:10.1016/j.neures.2009.09.1455
P3-p01 Effects of reversible inactivation of the ventral tegmental area on the expression of morphine-induced conditioned place preference in the rat Mahsa Moaddab, Pegah Azizi, Majid Hassanpour-Ezatti, Abbas Haghparast Neuroscience Research Center, Shahid Beheshti University, Tehran, Iran The mesolimbic dopamine pathway originating in the ventral tegmental area (VTA) is considered to be a fundamental component in regulating opioid reinforcement. In the present study, reversible inactivation of VTA was done through the unilateral and bilateral intra-VTA microinjection of 2% lidocaine just 10 min before the test session after the 3-day conditioning phase (5 mg/kg; s.c.) in male albino Wistar rats. Animal displacement, conditioning score and locomotor activity were recorded by Ethovision software. Our results indicated that bilateral but not unilateral intra-VTA injection of lidocaine decreased the expression of morphine-induced conditioned place preference (CPP) compared to saline-microinjected respective group. Therefore, our data further support the idea that the mesolimbic dopaminergic system has an important role in the memory-related mechanisms involved in the expression of morphine-induced CPP. doi:10.1016/j.neures.2009.09.1456
P3-p02 Effects of CB1 receptor antagonist within the nucleus accumbens on the expression of morphine-induced conditioned place preference in morphine-sensitized rats Pegah Azizi, Mahsa Moaddab, Majid Hassanpour-Ezatti, Abbas Haghparast Neuroscience Research Center, Shahid Beheshti University, M.C., Iran Morphine-induced sensitization is a major problem of morphine dependence and plays an important role in the abuse liability of opioid drugs. In the present study,
P3-o16 Colchicine-induced dentate granule cell loss impairs behavioral effects of acute but not chronic antidepressants Daisuke Miyamoto, Minoru Iijima, Hiroshi Nomura, Haruka Yamamoto, Norio Matsuki Lab. Chem. Pharmacol., Grad. Sch. Pharm., Univ. Tokyo, Japan It is controversial that adult-generated granule cells in the dentate gyrus are the target of antidepressants. To test whether the dentate granule cells are required for the behavioral effects of acute and chronic antidepressants treatments, we selectively ablated dentate granule cells by intrahippocampal colchicine injection. Acute treatments of desipramine or fluoxetine (20 mg/kg, i.p., 3 times) decreased the immobility in the forced swimming test (FST) in control rats, but not in colchicine injected rats. Chronic treatments of desipramine or fluoxetine (10 mg/kg, p.o., 28days) decreased the immobility in FST and the latency to feed in novelty suppressed feeding test in both control and colchicine injected rats. We confirmed the decrease of proliferating cells in the subgranular zone by immunohistochemistry for BrdU in the colchicine injected rats and the decrease was not reversed by chronic antidepressant. These findings suggest that the dentate granule cells are not essential for the behavioral effects of chronic antidepressants. doi:10.1016/j.neures.2009.09.1451
S255
P3-o19 Intense exercise-induced depression-like behavior is improved by imipramine in mice Kaori Nagasaka, Yasushi Kanai, Akiko Muroyama, Yasuhide Mitsumoto Dept. of Alternative Med. and Exp. Therapeutics, Faculty of Pharmaceutical Sciences, Hokuriku University, Japan Exercise training has been well recognized as an important strategy to counteract the risk factors related to neurodegenerative and psychiatric disorders, such as depression and anxiety. Some exercise can be also injurious to tissues. In fact, this kind of exercise generates high levels of reactive oxygen species, leading to oxidative damage in brain. In this study, we showed that intense exercise (IE, run on treadmill at a speed of 10 m/min for 30 min each day for 1 week) led to depression-like behavior in mice using a behavioral paradigm of forced swimming test (FST). Imipramine (10 mg/kg, i.p.) completely reversed the increased immobility time in the FST in the exercised mice. Locomotor activity was not influenced by IE. Theses results indicate that IE certainly becomes a physical stress, which leads to depression-like behavior. IE could induce the alteration of brain environment, because the emotional abnormality was improved by a known antidepressant. doi:10.1016/j.neures.2009.09.1454
P3-o20 Lowering barometric pressure aggravates depression-like behavior in rats Jun Sato, Kanoko Fukaya, Hiroyuki Mizoguchi
anxiety/
Res. Inst. Environ. Med., Nagoya Univ., Nagoya, Japan
P3-o17 Diesel exhaust particles during fetal period increase anxietylike behavior Akira Sato 1 , Satoshi Yokota 1 , Keisuke Mizuo 2 , Nozomu Moriya 1 , Isao Sugawara 3 , Ken Takeda 1 1 Lab. of Hygienic Chemistry, Grad. Sch. of Medicine, Tokyo Univ. of Sci., Japan; 2 Research Center for Health Science of Nanoparticles, Tokyo University of Science, Japan; 3 The Research Institute of Tuberculosis, Japan
Diesel exhaust (DE) is a major contributor to air pollution. It has been reported that DE causes various adverse health effects; however, the influence of DE on the brain has yet to be clarified. We investigated the effects of exposure to diesel exhaust particles (DEP) during fetal period on the central nervous system in mice using several behavioral tests. In the elevated plus maze test, DEP exposure significantly increased the number of entries into the open arms of the maze, but there was no difference between DEP administered and control mice in other tests. That mice administered with DEP during the fetal period display increased anxiety-like behavior suggests that DEP exposure may lead them to more easily experience anxiety. doi:10.1016/j.neures.2009.09.1452
P3-o18 Influence of chronic cerebral hypoperfusion on depressive phenotypes Kaichi Yoshizaki 1,2 , Yoshinobu Hara 1 , Hideaki Wakita 2 , Noriko Osumi 1 1
Div. Dev. Neurosci., Univ. of Tohoku, Miyagi, Japan; Nat. Inst. for Longevi. Sci., Aichi, Japan
2
Vasc. Dement. Res.,
Although previous studies have demonstrated that hypoperfusion in the prefrontal cortex and anterior cingulate gyrus is involved in the pathophysiology of depression, the etiology and pathologic mechanisms of depression by cerebral hypoperfusion remain unclear. Here we attempted to investigate the influence of chronic cerebral hypopefusion on depressive phenotypes. Mice (C57BL6/J, male, 12-week-old) subjected to permanent right unilateral common carotid artery occlusion (UCCAO) were investigated for depression-like behaviors by open field test (OFT), novel suppressed feeding test (NSFT) and sucrose consumption test (SCT) at 1 and 4 weeks after the surgery. The results showed that mice subjected to right UCCAO did not exhibit any differences in OFT, NSFT and SCT, although these right UCCAO mice exhibit impaired cognitive functions (Yoshizaki et al., 2008). Now we assess the depression-like behaviors in mice subjected to left UCCAO to investigate the influence of unilateral cerebral hypoperfusion as an etiology of the depressive phenotypes. doi:10.1016/j.neures.2009.09.1453
Weather changes have been known to influence the condition among patients with mood disorders. However, there is no relevant animal model for testing the influence of climatic factors on emotional impairment. Firstly we examined the effect of lowering barometric pressure (LP) on the immobility time (IT) in the forced swim test (FST) in rats, which is considered as an index of learned helplessness. When the rats were exposed to daily repeated FST, the IT gradually increased. This increment was inhibited by chronic administration of antidepressant (imipramine), suggesting that the immobility is anxiety/depression-like behavior. LP (27 hPa below the atmospheric pressure) increased IT in rats submitted to the repeated FST. Secondarily we examined the effect of daily LP exposure on the maintenance of IT after withdrawal from 6-day FST. When the rats were challenged in FST under LP condition on day 14 after the withdrawal, IT was significantly longer than those in non-conditioned rats. The current findings demonstrate that LP in the range of natural weather changes augmented the anxiety/depression-like behavior in rats. doi:10.1016/j.neures.2009.09.1455
P3-p01 Effects of reversible inactivation of the ventral tegmental area on the expression of morphine-induced conditioned place preference in the rat Mahsa Moaddab, Pegah Azizi, Majid Hassanpour-Ezatti, Abbas Haghparast Neuroscience Research Center, Shahid Beheshti University, Tehran, Iran The mesolimbic dopamine pathway originating in the ventral tegmental area (VTA) is considered to be a fundamental component in regulating opioid reinforcement. In the present study, reversible inactivation of VTA was done through the unilateral and bilateral intra-VTA microinjection of 2% lidocaine just 10 min before the test session after the 3-day conditioning phase (5 mg/kg; s.c.) in male albino Wistar rats. Animal displacement, conditioning score and locomotor activity were recorded by Ethovision software. Our results indicated that bilateral but not unilateral intra-VTA injection of lidocaine decreased the expression of morphine-induced conditioned place preference (CPP) compared to saline-microinjected respective group. Therefore, our data further support the idea that the mesolimbic dopaminergic system has an important role in the memory-related mechanisms involved in the expression of morphine-induced CPP. doi:10.1016/j.neures.2009.09.1456
P3-p02 Effects of CB1 receptor antagonist within the nucleus accumbens on the expression of morphine-induced conditioned place preference in morphine-sensitized rats Pegah Azizi, Mahsa Moaddab, Majid Hassanpour-Ezatti, Abbas Haghparast Neuroscience Research Center, Shahid Beheshti University, M.C., Iran Morphine-induced sensitization is a major problem of morphine dependence and plays an important role in the abuse liability of opioid drugs. In the present study,