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Choudhary AG, Awathale SN, Dudhabhate BB, Pawar N, Jadhav G, Upadhya MA, Khedkar T, Gadhikar YA, Sakharkar AJ, Subhedar NK, Kokare DM. Response of nitrergic system in the brain of rat conditioned to intracranial self-stimulation. J Neurochem 2024; 168:1402-1419. [PMID: 38445395 DOI: 10.1111/jnc.16090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 02/15/2024] [Accepted: 02/21/2024] [Indexed: 03/07/2024]
Abstract
The role of nitrergic system in modulating the action of psychostimulants on reward processing is well established. However, the relevant anatomical underpinnings and scope of the involved interactions with mesolimbic dopaminergic system have not been clarified. Using immunohistochemistry, we track the changes in neuronal nitric oxide synthase (nNOS) containing cell groups in the animals conditioned to intracranial self-stimulation (ICSS) via an electrode implanted in the lateral hypothalamus-medial forebrain bundle (LH-MFB) area. An increase in the nNOS immunoreactivity was noticed in the cells and fibers in the ventral tegmental area (VTA) and nucleus accumbens shell (AcbSh), the primary loci of the reward system. In addition, nNOS was up-regulated in the nucleus accumbens core (AcbC), vertical limb of diagonal band (VDB), locus coeruleus (LC), lateral hypothalamus (LH), superficial gray layer (SuG) of the superior colliculus, and periaqueductal gray (PAG). The brain tissue fragments drawn from these areas showed a change in nNOS mRNA expression, but in opposite direction. Intracerebroventricular (icv) administration of nNOS inhibitor, 7-nitroindazole (7-NI) showed decreased lever press activity in a dose-dependent manner in ICSS task. While an increase in the dopamine (DA) and 3, 4-dihydroxyphenylacetic acid (DOPAC) efflux was noted in the microdialysates collected from the AcbSh of ICSS rats, pre-administration of 7-NI (icv route) attenuated the response. The study identifies nitrergic centers that probably mediate sensory, cognitive, and motor components of the goal-directed behavior.
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Affiliation(s)
- Amit G Choudhary
- Department of Pharmaceutical Sciences, Rashtrasant Tukadoji Maharaj Nagpur University, Nagpur, India
| | - Sanjay N Awathale
- Department of Pharmaceutical Sciences, Rashtrasant Tukadoji Maharaj Nagpur University, Nagpur, India
| | - Biru B Dudhabhate
- Department of Pharmaceutical Sciences, Rashtrasant Tukadoji Maharaj Nagpur University, Nagpur, India
| | - Namrata Pawar
- Department of Biotechnology, Savitribai Phule Pune University, Pune, India
| | - Gouri Jadhav
- Department of Biotechnology, Savitribai Phule Pune University, Pune, India
| | - Manoj A Upadhya
- Indian Institute of Science Education and Research (IISER), Pune, India
| | - Trupti Khedkar
- Department of Zoology, Nabira Mahavidyalay, Katol, India
| | - Yashashree A Gadhikar
- Department of Zoology, Government Vidarbha Institute of Science and Humanities, Amravati, India
| | - Amul J Sakharkar
- Department of Biotechnology, Savitribai Phule Pune University, Pune, India
| | | | - Dadasaheb M Kokare
- Department of Pharmaceutical Sciences, Rashtrasant Tukadoji Maharaj Nagpur University, Nagpur, India
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2
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Neuropeptide S facilitates extinction of fear via modulation of mesolimbic dopaminergic circuitry. Neuropharmacology 2022; 221:109274. [DOI: 10.1016/j.neuropharm.2022.109274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 09/12/2022] [Accepted: 09/26/2022] [Indexed: 11/07/2022]
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Wada M, Noda Y, Iwata Y, Tsugawa S, Yoshida K, Tani H, Hirano Y, Koike S, Sasabayashi D, Katayama H, Plitman E, Ohi K, Ueno F, Caravaggio F, Koizumi T, Gerretsen P, Suzuki T, Uchida H, Müller DJ, Mimura M, Remington G, Grace AA, Graff-Guerrero A, Nakajima S. Dopaminergic dysfunction and excitatory/inhibitory imbalance in treatment-resistant schizophrenia and novel neuromodulatory treatment. Mol Psychiatry 2022; 27:2950-2967. [PMID: 35444257 DOI: 10.1038/s41380-022-01572-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 03/31/2022] [Accepted: 04/07/2022] [Indexed: 12/13/2022]
Abstract
Antipsychotic drugs are the mainstay in the treatment of schizophrenia. However, one-third of patients do not show adequate improvement in positive symptoms with non-clozapine antipsychotics. Additionally, approximately half of them show poor response to clozapine, electroconvulsive therapy, or other augmentation strategies. However, the development of novel treatment for these conditions is difficult due to the complex and heterogenous pathophysiology of treatment-resistant schizophrenia (TRS). Therefore, this review provides key findings, potential treatments, and a roadmap for future research in this area. First, we review the neurobiological pathophysiology of TRS, particularly the dopaminergic, glutamatergic, and GABAergic pathways. Next, the limitations of existing and promising treatments are presented. Specifically, this article focuses on the therapeutic potential of neuromodulation, including electroconvulsive therapy, repetitive transcranial magnetic stimulation, transcranial direct current stimulation, and deep brain stimulation. Finally, we propose multivariate analyses that integrate various perspectives of the pathogenesis, such as dopaminergic dysfunction and excitatory/inhibitory imbalance, thereby elucidating the heterogeneity of TRS that could not be obtained by conventional statistics. These analyses can in turn lead to a precision medicine approach with closed-loop neuromodulation targeting the detected pathophysiology of TRS.
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Affiliation(s)
- Masataka Wada
- Department of Neuropsychiatry, Keio University, School of Medicine, Tokyo, Japan
| | - Yoshihiro Noda
- Department of Neuropsychiatry, Keio University, School of Medicine, Tokyo, Japan
| | - Yusuke Iwata
- Department of Neuropsychiatry, University of Yamanashi Faculty of Medicine, Yamanashi, Japan
| | - Sakiko Tsugawa
- Department of Neuropsychiatry, Keio University, School of Medicine, Tokyo, Japan
| | - Kazunari Yoshida
- Department of Neuropsychiatry, Keio University, School of Medicine, Tokyo, Japan.,Tanenbaum Centre for Pharmacogenetics, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada.,Azrieli Adult Neurodevelopmental Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada.,Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Hideaki Tani
- Department of Neuropsychiatry, Keio University, School of Medicine, Tokyo, Japan
| | - Yoji Hirano
- Department of Neuropsychiatry, Kyushu University, Fukuoka, Japan.,Neural Dynamics Laboratory, Research Service, VA Boston Healthcare System, and Department of Psychiatry, Harvard Medical School, Boston, MA, USA
| | - Shinsuke Koike
- Center for Evolutionary Cognitive Sciences, Graduate School of Art and Sciences, The University of Tokyo, Tokyo, Japan
| | - Daiki Sasabayashi
- Department of Neuropsychiatry, University of Toyama Graduate School of Medicine and Pharmaceutical Sciences, Toyama, Japan.,Research Center for Idling Brain Science, University of Toyama, Toyama, Japan
| | - Haruyuki Katayama
- Department of Neuropsychiatry, Keio University, School of Medicine, Tokyo, Japan
| | - Eric Plitman
- Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Kazutaka Ohi
- Department of Psychiatry, Gifu University Graduate School of Medicine, Gifu, Japan
| | - Fumihiko Ueno
- Department of Neuropsychiatry, Keio University, School of Medicine, Tokyo, Japan.,Department of Psychiatry, University of Toronto, Toronto, ON, Canada.,Brain Health Imaging Centre, Centre for Addiction and Mental Health (CAMH), Toronto, ON, Canada
| | - Fernando Caravaggio
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada.,Brain Health Imaging Centre, Centre for Addiction and Mental Health (CAMH), Toronto, ON, Canada
| | - Teruki Koizumi
- Department of Neuropsychiatry, Keio University, School of Medicine, Tokyo, Japan.,Department of Psychiatry, National Hospital Organization Shimofusa Psychiatric Medical Center, Chiba, Japan
| | - Philip Gerretsen
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada.,Brain Health Imaging Centre, Centre for Addiction and Mental Health (CAMH), Toronto, ON, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, Canada.,Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Takefumi Suzuki
- Department of Neuropsychiatry, University of Yamanashi Faculty of Medicine, Yamanashi, Japan
| | - Hiroyuki Uchida
- Department of Neuropsychiatry, Keio University, School of Medicine, Tokyo, Japan
| | - Daniel J Müller
- Tanenbaum Centre for Pharmacogenetics, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada.,Department of Psychiatry, University of Toronto, Toronto, ON, Canada.,Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Masaru Mimura
- Department of Neuropsychiatry, Keio University, School of Medicine, Tokyo, Japan
| | - Gary Remington
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada.,Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Anthony A Grace
- Departments of Neuroscience, Psychiatry and Psychology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Ariel Graff-Guerrero
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada.,Brain Health Imaging Centre, Centre for Addiction and Mental Health (CAMH), Toronto, ON, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, Canada.,Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Shinichiro Nakajima
- Department of Neuropsychiatry, Keio University, School of Medicine, Tokyo, Japan. .,Brain Health Imaging Centre, Centre for Addiction and Mental Health (CAMH), Toronto, ON, Canada.
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Awathale SN, Waghade AM, Kawade HM, Jadhav G, Choudhary AG, Sagarkar S, Sakharkar AJ, Subhedar NK, Kokare DM. Neuroplastic Changes in the Superior Colliculus and Hippocampus in Self-rewarding Paradigm: Importance of Visual Cues. Mol Neurobiol 2021; 59:890-915. [PMID: 34797522 DOI: 10.1007/s12035-021-02597-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 10/11/2021] [Indexed: 12/21/2022]
Abstract
Coincident excitation via different sensory modalities encoding objects of positive salience is known to facilitate learning and memory. With a view to dissect the contribution of visual cues in inducing adaptive neural changes, we monitored the lever press activity of a rat conditioned to self-administer sweet food pellets in the presence/absence of light cues. Application of light cues facilitated learning and consolidation of long-term memory. The superior colliculus (SC) of rats trained on light cue showed increased neuronal activity, dendritic branching, and brain-derived neurotrophic factor (BDNF) protein and mRNA expression. Concomitantly, the hippocampus showed augmented neurogenesis as well as BDNF protein and mRNA expression. While intra-SC administration of U0126 (inhibitor of ERK 1/2 and long-term memory) impaired memory formation, lidocaine (local anaesthetic) hindered memory recall. The light cue-dependent sweet food pellet self-administration was coupled with increased efflux of dopamine (DA) and 3,4-dihydroxyphenylacetic acid (DOPAC) in the nucleus accumbens shell (AcbSh). In conditioned rats, pharmacological inhibition of glutamatergic signalling in dentate gyrus (DG) reduced lever press activity, as well as DA and DOPAC secretion in the AcbSh. We suggest that the neuroplastic changes in the SC and hippocampus might represent memory engrams sculpted by visual cues encoding reward information.
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Affiliation(s)
- Sanjay N Awathale
- Department of Pharmaceutical Sciences, Rashtrasant Tukadoji Maharaj Nagpur University, Nagpur, 440 033, India
| | - Akash M Waghade
- Department of Pharmaceutical Sciences, Rashtrasant Tukadoji Maharaj Nagpur University, Nagpur, 440 033, India
| | - Harish M Kawade
- Department of Pharmaceutical Sciences, Rashtrasant Tukadoji Maharaj Nagpur University, Nagpur, 440 033, India
| | - Gouri Jadhav
- Department of Biotechnology, Savitribai Phule Pune University, Pune, 411 007, India
| | - Amit G Choudhary
- Indian Institute of Science Education and Research (IISER), Dr. Homi Bhabha Road, Pune, 411 008, India
| | - Sneha Sagarkar
- Department of Zoology, Savitribai Phule Pune University, Pune, 411 007, India
| | - Amul J Sakharkar
- Department of Biotechnology, Savitribai Phule Pune University, Pune, 411 007, India
| | - Nishikant K Subhedar
- Indian Institute of Science Education and Research (IISER), Dr. Homi Bhabha Road, Pune, 411 008, India
| | - Dadasaheb M Kokare
- Department of Pharmaceutical Sciences, Rashtrasant Tukadoji Maharaj Nagpur University, Nagpur, 440 033, India.
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Awathale SN, Choudhary AG, Subhedar NK, Kokare DM. Neuropeptide CART modulates dopamine turnover in the nucleus accumbens: Insights into the anatomy of rewarding circuits. J Neurochem 2021; 158:1172-1185. [PMID: 34287909 DOI: 10.1111/jnc.15479] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 07/18/2021] [Accepted: 07/18/2021] [Indexed: 12/25/2022]
Abstract
Neuropeptide cocaine- and amphetamine-regulated transcript (CART) is known to influence the activity of the canonical mesolimbic dopaminergic pathway and modulate reward seeking behaviour. CART neurons of the lateral hypothalamus (LH) send afferents to the ventral tegmental area (VTA) and paraventricular thalamic nucleus (PVT) and these nuclei, in turn, send secondary projections to nucleus accumbens. We try to dissect the precise sites of CART's action in these circuits in promoting reward. Rats were implanted with bipolar electrode targeted at the lateral hypothalamus-medial forebrain bundle (LH-MFB) and trained to press the lever through intracranial self-stimulation (ICSS) protocol. CART (55-102) administered directly into posterior VTA (pVTA) or PVT of the conditioned rats significantly increased the number of lever presses, indicating reward-promoting activity of the peptide. Concomitant increase in dopamine (DA) and 3, 4-dihydroxyphenylacetic acid (DOPAC) efflux was noted in the microdialysate collected from the nucleus accumbens shell (AcbSh). On the other hand, immunoneutralization of endogenous CART with CART antibodies injected directly in the pVTA or PVT reduced the lever press activity as well as DA and DOPAC efflux in the AcbSh. Injection of CART (1-39) in pVTA or PVT was ineffective. We suggest that CART cells in the LH-MFB area send afferents to (a) pVTA and influence dopaminergic neurons projecting to AcbSh and (b) PVT, from where the secondary neurons may feed into the AcbSh. Excitation of the CARTergic pathway to the pVTA as well as the PVT seems to promote DA release in the AcbSh and contribute to the generation of reward.
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Affiliation(s)
- Sanjay N Awathale
- Department of Pharmaceutical Sciences, Rashtrasant Tukadoji Maharaj Nagpur University, Nagpur, India
| | - Amit G Choudhary
- Indian Institute of Science Education and Research (IISER), Pune, India
| | | | - Dadasaheb M Kokare
- Department of Pharmaceutical Sciences, Rashtrasant Tukadoji Maharaj Nagpur University, Nagpur, India
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Keramatian A, Alaei H, Eidi A, Radahmadi M. Electrical stimulation mPFC affects morphine addiction by changing glutamate concentration in the ventral tegmental area. Metab Brain Dis 2019; 34:1171-1180. [PMID: 31115726 DOI: 10.1007/s11011-019-00426-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 04/28/2019] [Indexed: 11/26/2022]
Abstract
Morphine addiction is known as a serious social problem. Medial prefrontal cortex (mPFC) and ventral tegmental area (VTA) are two important sites of the brain that contribute to this type of addiction, and a complicated relation exists in between. In addition, neurotransmitters like glutamate and γ--Amino Butyric Acid (GABA) play an important role in the formation of these relations. Thus, the present study was undertaken to investigate these relations by evaluating the level of associated changes in the indicated neurotransmitters in the VTA, using HPLC method. This was performed after electrical stimulation and inducing lesion of mPFC and through microinjections of N-Methyl-D-Aspartate (NMDA) and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor antagonists, respectively AP5 and CNQX, into the VTA of addicted rats. Our results showed that intra-peritoneal (i.p.) administration of morphine in 9 days in the morphine group, and also electrical stimulation (100 μA) of mPFC, receiving (i.p.) morphine, caused an increase in the glutamate release in the VTA, compared to the control group, but the increase of glutamate levels in the VTA in the morphine-stimulation group was not significant, compared to the morphine group. Moreover, GABA release into this area was decreasing in morphine and morphine- stimulation groups, compared to the control group. Our findings also showed that electrical lesion (0.4 mA) of mPFC, and also microinjection of glutamate antagonists into the VTA, receiving (i.p.) morphine in rats, caused a decrease of glutamate in the VTA. Therefore, it could be concluded that the relation between mPFC and VTA is highly effective in the formation of reward system.
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Affiliation(s)
- Asal Keramatian
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Hojjatallah Alaei
- Department of Physiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
| | - Akram Eidi
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Maryam Radahmadi
- Department of Physiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
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Ramshini E, Alaei H, Reisi P, Naghdi N, Afrozi H, Alaei S, Alehashem M, Eftekharvaghefi S. Effect of intracerebroventricular injection of GABA receptors antagonists on morphine-induced changes in GABA and GLU transmission within the mPFC: an in vivo microdialysis study. IRANIAN JOURNAL OF BASIC MEDICAL SCIENCES 2019; 22:246-250. [PMID: 31156783 PMCID: PMC6528724 DOI: 10.22038/ijbms.2019.28478.6925] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Objective(s): Many studies have focused on ventral tegmental area than of other mesocorticolimbic areas, and implicated a key role for the medial prefrontal cortex (mPFC) in the development of addictive behaviors. So far, the role of gamma-aminobutyric acid (GABA) receptors in the discriminative properties of morphine has received little attention and few studies evaluated the role of these receptors in drug dependence. Hence, we investigated the role of this receptor on morphine- induced GABA/ glutamate (GLU) changes in the mPFC following morphine administration using in vivo microdialysis. Materials and Methods: In this study, 60 rats weighing 270-300 g were divided into six groups. First, microdialysis probe was inserted into the mPFC and was perfused with artificial cerebrospinal fluid and collected the baseline samples in all groups. In saline and morphine groups, the saline, in phaclophen and (phaclofen+morphine) groups, phaclofen (100 nmol), and in bicuculline and (bicuculline+morphine) groups, bicuculline (20 nmol) was injected intracerebroventricular. In saline, phaclofen and bicuculline groups 20 min later, animals received saline (0.2 ml, IP) and others groups received morphine (20 mg/kg, IP). Results: Our results showed that morphine increased the average concentration of GABA and decreased the concentration of GLU within mPFC. Pretreatment with phaclofen and bicuculline 20 min before morphine administration had no effect on GABA and GLU release for 100 min. Conclusion: The present study indicated that morphine influence the GABA and GLU transmission in mPFC. Therefore evaluation of neurochemistry changes of this neural circuitry may provide further insight into the mechanisms underlying drug dependence.
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Affiliation(s)
- Effat Ramshini
- Department of Physiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Hojjatallah Alaei
- Department of Physiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Parham Reisi
- Department of Physiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Naser Naghdi
- Department of Physiology, Pasteur Institute of Iran, Tehran, Iran
| | | | - Samaneh Alaei
- Department of Physiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Maryam Alehashem
- Tracheal Diseases Research Center, National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Hayashida KI, Obata H. Strategies to Treat Chronic Pain and Strengthen Impaired Descending Noradrenergic Inhibitory System. Int J Mol Sci 2019; 20:ijms20040822. [PMID: 30769838 PMCID: PMC6412536 DOI: 10.3390/ijms20040822] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2019] [Revised: 02/04/2019] [Accepted: 02/12/2019] [Indexed: 12/28/2022] Open
Abstract
Gabapentinoids (gabapentin and pregabalin) and antidepressants (tricyclic antidepressants and serotonin noradrenaline reuptake inhibitors) are often used to treat chronic pain. The descending noradrenergic inhibitory system from the locus coeruleus (LC) to the dorsal horn of the spinal cord plays an important role in the analgesic mechanisms of these drugs. Gabapentinoids activate the LC by inhibiting the release of γ-aminobutyric acid (GABA) and inducing the release of glutamate, thereby increasing noradrenaline levels in the spinal cord. Antidepressants increase noradrenaline levels in the spinal cord by inhibiting reuptake, and accumulating noradrenaline inhibits chronic pain through α2-adrenergic receptors in the spinal cord. Recent animal studies, however, revealed that the function of the descending noradrenergic inhibitory system is impaired in chronic pain states. Other recent studies found that histone deacetylase inhibitors and antidepressants restore the impaired noradrenergic descending inhibitory system acting on noradrenergic neurons in the LC.
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Affiliation(s)
- Ken-Ichiro Hayashida
- Doctorial Course in Medicine, Organ Function-Oriented Medicine, Akita University Graduate School of Medicine;1-1-1, Hondo, Akita-City, Akita 010-8543, Japan.
| | - Hideaki Obata
- Center for Pain Management and Department of Anesthesiology, Fukushima Medical University; 1 Hikarigaoka, Fukushima-City, Fukushima 960-1295, Japan.
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Descending Noradrenergic Inhibition: An Important Mechanism of Gabapentin Analgesia in Neuropathic Pain. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1099:93-100. [DOI: 10.1007/978-981-13-1756-9_8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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10
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GABA levels in the ventromedial prefrontal cortex during the viewing of appetitive and disgusting food images. Neuroscience 2016; 333:114-22. [PMID: 27436536 DOI: 10.1016/j.neuroscience.2016.07.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Revised: 07/05/2016] [Accepted: 07/07/2016] [Indexed: 02/06/2023]
Abstract
Characterizing how the brain appraises the psychological dimensions of reward is one of the central topics of neuroscience. It has become clear that dopamine neurons are implicated in the transmission of both rewarding information and aversive and alerting events through two different neuronal populations involved in encoding the motivational value and the motivational salience of stimuli, respectively. Nonetheless, there is less agreement on the role of the ventromedial prefrontal cortex (vmPFC) and the related neurotransmitter release during the processing of biologically relevant stimuli. To address this issue, we employed magnetic resonance spectroscopy (MRS), a non-invasive methodology that allows detection of some metabolites in the human brain in vivo, in order to assess the role of the vmPFC in encoding stimulus value rather than stimulus salience. Specifically, we measured gamma-aminobutyric acid (GABA) and, with control purposes, Glx levels in healthy subjects during the observation of appetitive and disgusting food images. We observed a decrease of GABA and no changes in Glx concentration in the vmPFC in both conditions. Furthermore, a comparatively smaller GABA reduction during the observation of appetitive food images than during the observation of disgusting food images was positively correlated with the scores obtained to the body image concerns sub-scale of Body Uneasiness Test (BUT). These results are consistent with the idea that the vmPFC plays a crucial role in processing both rewarding and aversive stimuli, possibly by encoding stimulus salience through glutamatergic and/or noradrenergic projections to deeper mesencephalic and limbic areas.
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Locklear MN, Cohen AB, Jone A, Kritzer MF. Sex Differences Distinguish Intracortical Glutamate Receptor-Mediated Regulation of Extracellular Dopamine Levels in the Prefrontal Cortex of Adult Rats. Cereb Cortex 2016; 26:599-610. [PMID: 25260707 PMCID: PMC4712796 DOI: 10.1093/cercor/bhu222] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Executive functions of the prefrontal cortex (PFC) are sensitive to local dopamine (DA) levels. Although sex differences distinguish these functions and their dysfunction in disease, the basis for this is unknown. We asked whether sex differences might result from dimorphisms in the glutamatergic mechanisms that regulate PFC DA levels. Using antagonists selective for α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and N-methyl-d-aspartate (NMDA) receptors, we compared drug effects on in vivo microdialysis DA measurements in the PFC of adult male and female rats. We found that baseline DA levels were similar across sex, AMPA antagonism decreased PFC DA in both sexes, and NMDA antagonism increased DA in males but decreased DA in females. We also found that, at subseizure-producing drug levels, γ-aminobutyric acid (GABA)-A antagonism did not affect DA in either sex but that GABA-B antagonism transiently increased PFC DA in both sexes, albeit more so in females. Finally, when NMDA antagonism was coincident with GABA-B antagonism, PFC DA levels in males responded as if to GABA-B antagonism alone, whereas in females, DA effects mirrored those induced by NMDA antagonism. Taken together, these data suggest commonalities and fundamental differences in the intracortical amino acid transmitter mechanisms that regulate DA homeostasis in the male and female rat PFCs.
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Affiliation(s)
- M N Locklear
- Graduate Program in Neuroscience Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY 11794-5230, USA
| | - A B Cohen
- Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY 11794-5230, USA
| | - A Jone
- Graduate Program in Neuroscience Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY 11794-5230, USA
| | - M F Kritzer
- Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY 11794-5230, USA
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12
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O'Connor WT, O'Shea SD. Clozapine and GABA transmission in schizophrenia disease models. Pharmacol Ther 2015; 150:47-80. [DOI: 10.1016/j.pharmthera.2015.01.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 01/06/2015] [Indexed: 11/30/2022]
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13
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Sex-specific enhanced behavioral toxicity induced by maternal exposure to a mixture of low dose endocrine-disrupting chemicals. Neurotoxicology 2014; 45:121-30. [PMID: 25454719 DOI: 10.1016/j.neuro.2014.09.008] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Revised: 09/15/2014] [Accepted: 09/15/2014] [Indexed: 01/12/2023]
Abstract
Humans are increasingly and consistently exposed to a variety of endocrine disrupting chemicals (EDCs), chemicals that have been linked to neurobehavioral disorders such as ADHD and autism. Many of such EDCs have been shown to adversely influence brain mesocorticolimbic systems raising the potential for cumulative toxicity. As such, understanding the effects of developmental exposure to mixtures of EDCs is critical to public health protection. Consequently, this study compared the effects of a mixture of four EDCs to their effects alone to examine potential for enhanced toxicity, using behavioral domains and paradigms known to be mediated by mesocorticolimbic circuits (fixed interval (FI) schedule controlled behavior, novel object recognition memory and locomotor activity) in offspring of pregnant mice that had been exposed to vehicle or relatively low doses of four EDCs, atrazine (ATR - 10mg/kg), perfluorooctanoic acid (PFOA - 0.1mg/kg), bisphenol-A (BPA - 50 μg/kg), 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD - 0.25 μg/kg) alone or combined in a mixture (MIX), from gestational day 7 until weaning. EDC-treated males maintained significantly higher horizontal activity levels across three testing sessions, indicative of delayed habituation, whereas no effects were found in females. Statistically significant effects of MIX were seen in males, but not females, in the form of increased FI response rates, in contrast to reductions in response rate with ATR, BPA and TCDD, and reduced short term memory in the novel object recognition paradigm. MIX also reversed the typically lower neophobia levels of males compared to females. With respect to individual EDCs, TCDD produced notable increases in FI response rates in females, and PFOA significantly increased ambulatory locomotor activity in males. Collectively, these findings show the potential for enhanced behavioral effects of EDC mixtures in males and underscore the need for animal studies to fully investigate mixtures, including chemicals that converge on common physiological substrates to examine potential mechanisms of toxicity with full dose effect curves to assist in interpretations of relevant mechanisms.
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Suto T, Severino AL, Eisenach JC, Hayashida KI. Gabapentin increases extracellular glutamatergic level in the locus coeruleus via astroglial glutamate transporter-dependent mechanisms. Neuropharmacology 2014; 81:95-100. [PMID: 24495399 DOI: 10.1016/j.neuropharm.2014.01.040] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Revised: 01/20/2014] [Accepted: 01/24/2014] [Indexed: 01/02/2023]
Abstract
Gabapentin has shown to be effective in animals and humans with acute postoperative and chronic pain. Yet the mechanisms by which gabapentin reduces pain have not been fully addressed. The current study performed in vivo microdialysis in the locus coeruleus (LC) in normal and spinal nerve ligated (SNL) rats to examine the effect of gabapentin on extracellular glutamate concentration and its mechanisms of action with focus on presynaptic GABA-B receptors, astroglial glutamate transporter-1 (GLT-1), and interactions with α2δ subunits of voltage-gated Ca(2+) channels and endogenous noradrenaline. Basal extracellular concentration and tissue content of glutamate in the LC were greater in SNL rats than normal ones. Intravenously administered and LC-perfused gabapentin increased extracellular glutamate concentration in the LC. The net amount of glutamate increased by gabapentin is larger in SNL rats compared with normal ones, although the percentage increases from the baseline did not differ. The gabapentin-related α2δ ligand pregabalin increased extracellular glutamate concentration in the LC, whereas another α2δ ligand, 3-exo-aminobicyclo [2.2.1] heptane-2-exo-carboxylic acid (ABHCA), did not. Selective blockade by the dihydrokainic acid or knock-down of GLT-1 by the small interfering RNA abolished the gabapentin-induced glutamate increase in the LC, whereas blockade of GABA-B receptors by the CGP-35348 and depletion of noradrenalin by the dopamine-β-hydroxylase antibody conjugated to saporin did not. These results suggest that gabapentin induces glutamate release from astrocytes in the LC via GLT-1-dependent mechanisms to stimulate descending inhibition. The present study also demonstrates that this target of gabapentin in astrocytes does not require interaction with α2δ subunits in neurons.
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Affiliation(s)
- Takashi Suto
- Department of Anesthesiology, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157, USA
| | - Amie L Severino
- Department of Anesthesiology, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157, USA
| | - James C Eisenach
- Department of Anesthesiology, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157, USA
| | - Ken-ichiro Hayashida
- Department of Anesthesiology, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157, USA.
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15
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Brisch R, Saniotis A, Wolf R, Bielau H, Bernstein HG, Steiner J, Bogerts B, Braun K, Jankowski Z, Kumaratilake J, Henneberg M, Gos T, Henneberg M, Gos T. The role of dopamine in schizophrenia from a neurobiological and evolutionary perspective: old fashioned, but still in vogue. Front Psychiatry 2014; 5:47. [PMID: 24904434 PMCID: PMC4032934 DOI: 10.3389/fpsyt.2014.00047] [Citation(s) in RCA: 178] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Accepted: 04/23/2014] [Indexed: 12/12/2022] Open
Abstract
Dopamine is an inhibitory neurotransmitter involved in the pathology of schizophrenia. The revised dopamine hypothesis states that dopamine abnormalities in the mesolimbic and prefrontal brain regions exist in schizophrenia. However, recent research has indicated that glutamate, GABA, acetylcholine, and serotonin alterations are also involved in the pathology of schizophrenia. This review provides an in-depth analysis of dopamine in animal models of schizophrenia and also focuses on dopamine and cognition. Furthermore, this review provides not only an overview of dopamine receptors and the antipsychotic effects of treatments targeting them but also an outline of dopamine and its interaction with other neurochemical models of schizophrenia. The roles of dopamine in the evolution of the human brain and human mental abilities, which are affected in schizophrenia patients, are also discussed.
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Affiliation(s)
- Ralf Brisch
- Department of Forensic Medicine, Medical University of Gdańsk , Gdańsk , Poland
| | - Arthur Saniotis
- School of Medical Sciences, The University of Adelaide , Adelaide, SA , Australia ; Centre for Evolutionary Medicine, University of Zurich , Zurich , Switzerland
| | - Rainer Wolf
- Department of Psychiatry and Psychotherapy, Ruhr University Bochum , Bochum , Germany
| | - Hendrik Bielau
- Department of Psychiatry, Otto-von-Guericke-University of Magdeburg , Magdeburg , Germany
| | - Hans-Gert Bernstein
- Department of Psychiatry, Otto-von-Guericke-University of Magdeburg , Magdeburg , Germany
| | - Johann Steiner
- Department of Psychiatry, Otto-von-Guericke-University of Magdeburg , Magdeburg , Germany
| | - Bernhard Bogerts
- Department of Psychiatry, Otto-von-Guericke-University of Magdeburg , Magdeburg , Germany
| | - Katharina Braun
- Department of Zoology, Institute of Biology, Otto-von-Guericke-University of Magdeburg , Magdeburg , Germany
| | - Zbigniew Jankowski
- Department of Forensic Medicine, Medical University of Gdańsk , Gdańsk , Poland
| | - Jaliya Kumaratilake
- Biological Anthropology and Comparative Anatomy Research Unit, School of Biomedical Sciences, The University of Adelaide , Adelaide, SA , Australia
| | - Maciej Henneberg
- Biological Anthropology and Comparative Anatomy Research Unit, School of Biomedical Sciences, The University of Adelaide , Adelaide, SA , Australia
| | - Tomasz Gos
- Department of Forensic Medicine, Medical University of Gdańsk , Gdańsk , Poland
| | - Maciej Henneberg
- Biological Anthropology and Comparative Anatomy Research Unit, School of Biomedical Sciences, The University of Adelaide , Adelaide, SA , Australia
| | - Tomasz Gos
- Department of Forensic Medicine, Medical University of Gdańsk , Gdańsk , Poland
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Hearing M, Kotecki L, Marron Fernandez de Velasco E, Fajardo-Serrano A, Chung HJ, Luján R, Wickman K. Repeated cocaine weakens GABA(B)-Girk signaling in layer 5/6 pyramidal neurons in the prelimbic cortex. Neuron 2013; 80:159-70. [PMID: 24094109 DOI: 10.1016/j.neuron.2013.07.019] [Citation(s) in RCA: 93] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/16/2013] [Indexed: 01/18/2023]
Abstract
Repeated cocaine exposure triggers adaptations in layer 5/6 glutamatergic neurons in the medial prefrontal cortex (mPFC) that promote behavioral sensitization and drug-seeking behavior. While suppression of metabotropic inhibitory signaling has been implicated in these behaviors, underlying mechanisms are unknown. Here, we show that Girk/K(IR)3 channels mediate most of the GABA(B) receptor (GABA(B)R)-dependent inhibition of layer 5/6 pyramidal neurons in the mPFC and that repeated cocaine suppresses this pathway. This adaptation was selective for GABA(B)R-dependent Girk signaling in layer 5/6 pyramidal neurons of the prelimbic cortex (PrLC) and involved a D₁/₅ dopamine receptor- and phosphorylation-dependent internalization of GABA(B)R and Girk channels. Persistent suppression of Girk signaling in layer 5/6 of the dorsal mPFC enhanced cocaine-induced locomotor activity and occluded behavioral sensitization. Thus, the cocaine-induced suppression of GABA(B)R-Girk signaling in layer 5/6 pyramidal neurons of the prelimbic cortex appears to represent an early adaptation critical for promoting addiction-related behavior.
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Affiliation(s)
- Matthew Hearing
- Department of Pharmacology, University of Minnesota, Minneapolis, MN 55455, USA
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Ahmadi H, Nasehi M, Rostami P, Zarrindast MR. Involvement of the nucleus accumbens shell dopaminergic system in prelimbic NMDA-induced anxiolytic-like behaviors. Neuropharmacology 2013; 71:112-23. [DOI: 10.1016/j.neuropharm.2013.03.017] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2012] [Revised: 03/21/2013] [Accepted: 03/23/2013] [Indexed: 01/21/2023]
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Fliegel S, Brand I, Spanagel R, Noori HR. Ethanol-induced alterations of amino acids measured by in vivo microdialysis in rats: a meta-analysis. In Silico Pharmacol 2013; 1:7. [PMID: 25505652 PMCID: PMC4230485 DOI: 10.1186/2193-9616-1-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Accepted: 05/07/2013] [Indexed: 12/14/2022] Open
Abstract
PURPOSE In recent years in vivo microdialysis has become an important method in research studies investigating the alterations of neurotransmitters in the extracellular fluid of the brain. Based on the major involvement of glutamate and γ-aminobutyric acid (GABA) in mediating a variety of alcohol effects in the mammalian brain, numerous microdialysis studies have focused on the dynamical behavior of these systems in response to alcohol. METHODS Here we performed multiple meta-analyses on published datasets from the rat brain: (i) we studied basal extracellular concentrations of glutamate and GABA in brain regions that belong to a neurocircuitry involved in neuropsychiatric diseases, especially in alcoholism (Noori et al., Addict Biol 17:827-864, 2012); (ii) we examined the effect of acute ethanol administration on glutamate and GABA levels within this network and (iii) we studied alcohol withdrawal-induced alterations in glutamate and GABA levels within this neurocircuitry. RESULTS For extraction of basal concentrations of these neurotransmitters, datasets of 6932 rats were analyzed and the absolute basal glutamate and GABA levels were estimated for 18 different brain sites. In response to different doses of acute ethanol administration, datasets of 529 rats were analyzed and a non-linear dose response (glutamate and GABA release) relationship was observed in several brain sites. Specifically, glutamate in the nucleus accumbens shows a decreasing logarithmic dose response curve. Finally, regression analysis of 11 published reports employing brain microdialysis experiments in 104 alcohol-dependent rats reveals very consistent augmented extracellular glutamate and GABA levels in various brain sites that correlate with the intensity of the withdrawal response were identified. CONCLUSIONS In summary, our results provide standardized basal values for future experimental and in silico studies on neurotransmitter release in the rat brain and may be helpful to understand the effect of ethanol on neurotransmitter release. Furthermore, this study illustrates the benefit of meta-analyses using the generalization of a wide range of preclinical data.
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Affiliation(s)
- Sarah Fliegel
- Institute of Psychopharmacology, Central Institute of Mental Health, Faculty of Medicine Mannheim, University of Heidelberg, J5, 68159 Mannheim, Germany
| | - Ines Brand
- Institute of Psychopharmacology, Central Institute of Mental Health, Faculty of Medicine Mannheim, University of Heidelberg, J5, 68159 Mannheim, Germany
| | - Rainer Spanagel
- Institute of Psychopharmacology, Central Institute of Mental Health, Faculty of Medicine Mannheim, University of Heidelberg, J5, 68159 Mannheim, Germany
| | - Hamid R Noori
- Institute of Psychopharmacology, Central Institute of Mental Health, Faculty of Medicine Mannheim, University of Heidelberg, J5, 68159 Mannheim, Germany
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Corriveau JA, Glenn MJ. Postnatal choline levels mediate cognitive deficits in a rat model of schizophrenia. Pharmacol Biochem Behav 2013; 103:60-8. [PMID: 22917834 DOI: 10.1016/j.pbb.2012.08.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Revised: 07/23/2012] [Accepted: 08/04/2012] [Indexed: 02/02/2023]
Abstract
In the present study, we investigated whether the essential nutrient choline may protect against schizophrenic-like cognitive deficits in a rat model. Theories regarding the etiology of schizophrenia suggest that early life events render an individual more vulnerable to adult challenges, and the combination may precipitate disease onset. To model this, the adult male offspring of dams who either experienced stress during late gestation or did not were given a 5 mg/kg dose of the NMDA antagonist,MK-801. The presence of both the prenatal challenge of stress and the adult challenge of MK-801 was expected to impair memory in these offspring. Memory was not expected to be impaired in rats that did not experience prenatal stress, but did receive MK-801 as adults. To study whether choline levels altered outcomes in these groups, rats were fed a choline-supplemented, -deficient, or standard diet during the period between the two challenges: beginning at weaning and continuing for 25 days. All rats consumed regular rat chow thereafter. The efficacy of the model was confirmed in the standard fed rats in that only those that were prenatally stressed and received MK-801 as adults displayed impaired memory on a novelty preference test of object recognition. Contrary to this finding and consistent with our hypothesis, choline-supplemented rats that were also both prenatally stressed and given MK-801 as adults showed intact memory. Choline deficiency impaired memory in rats that were just prenatally stressed, just given MK-801 as adults, and subjected to both. Thus, a choline deficient diet may render rats vulnerable to either challenge. Taken together, we offer evidence that developmental choline levels modulate the effects of prenatal stress and/or MK-801 and thereby alter the cognitive outcome in a rat model of schizophrenia.
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20
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Lesion of medial prefrontal cortex reduces morphine-induced extracellular dopamine level in the ventral tegmental area: A microdialysis study in rats. Pharmacol Biochem Behav 2012; 102:77-81. [DOI: 10.1016/j.pbb.2012.03.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Voigt RM, Herrold AA, Napier TC. Baclofen facilitates the extinction of methamphetamine-induced conditioned place preference in rats. Behav Neurosci 2012; 125:261-7. [PMID: 21463025 DOI: 10.1037/a0022893] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The powerful, long-lasting association between the rewarding effects of a drug and contextual cues associated with drug administration can be studied using conditioned place preference (CPP). The GABA(B) receptor agonist baclofen facilitates the extinction of morphine-induced CPP in mice. The current study extended this work by determining if baclofen could enhance the extinction of methamphetamine (Meth) CPP. CPP was established using a six-day conditioning protocol wherein Meth-pairings were alternated with saline-pairings. Rats were subsequently administered baclofen (2 mg/kg i.p. or vehicle) immediately after each daily forced extinction session, which consisted of a saline injection immediately prior to being placed into the previously Meth- or saline-paired chamber. One extinction training cycle, consisted of six once-daily forced extinction sessions, mimicking the alternating procedure established during conditioning, followed by a test for preference (Ext test). CPP persisted for at least four extinction cycles in vehicle-treated rats. In contrast, CPP was inhibited following a single extinction training cycle. These data indicate that Meth-induced CPP was resistant to extinction, but extinction training was rendered effective when the training was combined with baclofen. These findings converge with the prior demonstration of baclofen facilitating the extinction of morphine-induced CPP indicating that GABA(B) receptor actions are independent of the primary (unconditioned) stimulus (i.e., the opiate or the stimulant) and likely reflect mechanisms engaged by extinction learning processes per se. Thus, baclofen administered in conjunction with extinction training may be of value for addiction therapy regardless of the class of drug being abused.
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Affiliation(s)
- Robin M Voigt
- Rush University Medical Center, 1735 W. Harrison St., Chicago, IL 60612, USA.
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22
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Vallée N, Rissoe JJ, Blatteau JE. Effect of an hyperbaric nitrogen narcotic ambience on arginine and citrulline levels, the precursor and co-product of nitric oxide, in rat striatum. Med Gas Res 2011; 1:16. [PMID: 22146244 PMCID: PMC3231870 DOI: 10.1186/2045-9912-1-16] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Accepted: 07/05/2011] [Indexed: 11/21/2022] Open
Abstract
Previous studies performed in the laboratory have shown that nitrogen narcosis induces a decrease in striatal glutamate and dopamine levels. Although we stimulated the N-methyl-D-aspartate (NMDA) receptor, an important glutamate receptor required for motor and locomotor activity managed by the striatum, and demonstrated that the receptor was effective when exposed to nitrogen at 3MPa, it was not possible to return the striatal glutamate level to its base values. We conclude that it was the striatopetal neurons of the glutamatergic pathways that were mainly affected in this hyperbaric syndrome, without understanding the principal reasons. Hence we sought to establish what happens in the vicinity of the plasma membrane, downstream the NMDA-Receptor, and we used the hypothesis that there could be neuronal nitric oxide synthase (nNOS) disturbances. A microdialysis study was performed in rat striatum in order to analyse levels of citrulline, the NO co-product, and arginine, the NO precursor. Those both NO metabolites were detectable with an HPLC coupled to a fluorimetric detector. Exposure to pressurized nitrogen induced a reduction in citrulline (-18.9%) and arginine (-10.4%) levels. Under the control normobaric conditions, the striatal NMDA infusion enhanced the citrulline level (+85.6%), whereas under 3 MPa of nitrogen, the same NMDA infusion did not change the citrulline level which remains equivalent to that of the baseline. The level of arginine increased (+45.7%) under normobaric conditions but a decrease occurred in pressurized nitrogen (-51.6%). Retrodialysis with Saclofen and KCl in the prefrontal cortex under normobaric conditions led to an increase in striatal levels of citrulline (+30.5%) and a decrease in arginine levels (-67.4%). There was no significant difference when nitrogen at 3MPa was added. To conclude, the synthesis of citrulline/NO is reduced in nitrogen narcosis while it seems possible to activate it artificially by infusion. We have suggested that the low glutamate levels recorded in nitrogen narcosis induced these dopamine and NO reductions in the striatum.
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Affiliation(s)
- Nicolas Vallée
- Institut de Recherches Biomédicales des Armées-Antenne Toulon, Equipe Résidente de Recherche Opérationnelle, BP 20548, 83041 Toulon Cedex 9, France.
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Brown AM, Skamarauskas J, Lister T, Madjd A, Ray DE. Differential susceptibility of astrocytic and neuronal function to 3-chloropropanediol in the rat inferior colliculus. J Neurochem 2011; 116:996-1004. [PMID: 21155803 DOI: 10.1111/j.1471-4159.2010.07138.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
We have previously shown that systemic administration of S(+)3-chloropropanediol (3-CPD) produces a morphological loss of astrocytes in specific nuclei of the rodent brain that precedes loss of both neurones and endothelial tight junctions. Here, we have evaluated the differential susceptibility of neuronal and astrocytic function to 3-CPD, in order to see if this parallels the morphological selectivity. To do this, we have developed an in vivo method for monitoring astrocyte function over time by giving hourly 20-min bolus challenge exposures to ammonia via an implanted microdialysis probe and measuring the resulting transient increases in the extracellular glutamine : glutamate ratio. These challenge ammonia exposures evoked a stable response for at least 5 h when the probe was implanted in the rat inferior colliculus, but caused no behavioural response or morphological damage. Although 3-CPD produced a rapid and sustained abolition of the ammonia response within 2 h, the field potential response of inferior collicular neurones to sound fell significantly to 75.0 ± 3.9% pre-dose at up to 8 h but then fell markedly, reaching 20.5 ± 3.7% at 2 days. Blood flow in the inferior colliculus also showed only late changes, increasing substantially at 2 days. Astrocyte damage at the EM level was seen from 3 h, followed by loss of astrocytes from 18 h to a minimum of 7 ± 10% control at 3 days. The rapid abolition of the ammonia response suggests that in addition to selective astrocyte death, 3-CPD also produces an earlier impairment of astrocyte function that precedes loss of neuronal function. This initial functional selectivity of 3-CPD provides a potential investigative tool in neurochemical studies of astrocyte-neuronal interactions.
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Affiliation(s)
- Angus M Brown
- School of Biomedical Sciences, Queens Medical Centre, University of Nottingham, Nottingham, UK.
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Stimulation of medial prefrontal cortex serotonin 2C (5-HT(2C)) receptors attenuates cocaine-seeking behavior. Neuropsychopharmacology 2010; 35:2037-48. [PMID: 20520599 PMCID: PMC3055305 DOI: 10.1038/npp.2010.72] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Serotonin 2C receptor (5-HT(2C)R) agonists administered systemically attenuate both cocaine-primed and cue-elicited reinstatement of extinguished cocaine-seeking behavior. To further elucidate the function of these receptors in addiction-like processes, this study examined the effects of microinfusing the 5-HT(2C)R agonist MK212 (0, 10, 30, 100 ng/side/0.2 microl) into the medial prefrontal cortex (mPFC) on cocaine self-administration and reinstatement of extinguished cocaine-seeking behavior. Male Sprague-Dawley rats were trained to self-administer cocaine (0.75 mg/kg, i.v.) paired with light and tone cues. Once responding stabilized, rats received MK212 microinfusions before tests for maintenance of cocaine self-administration. Next, extinction training to reduce cocaine-seeking behavior, defined as responses performed without cocaine reinforcement available, occurred until low extinction baselines were achieved. Rats then received MK212 microinfusions before tests for reinstatement of extinguished cocaine-seeking behavior elicited by cocaine-priming injections (10 mg/kg, i.p.) or response-contingent presentations of the cocaine-associated cues; operant responses during cocaine-primed reinstatement tests produced no consequences. MK212 microinfusions into the prelimbic and infralimbic, but not anterior cingulate, regions of the mPFC dose-dependently attenuated both cocaine-primed and cue-elicited reinstatement of extinguished cocaine-seeking behavior, but did not reliably affect cocaine self-administration. A subsequent experiment showed that the effects of MK212 (100 ng/side/0.2 microl) on reinstatement of extinguished cocaine-seeking behavior were blocked by co-administration of the 5-HT(2C)R antagonist SB242084 (200 ng/side/0.2 microl). MK212 administered alone into the mPFC as a drug prime produced no discernable effects on cocaine-seeking behavior. These findings suggest that stimulation of 5-HT(2C)Rs in the mPFC attenuates the incentive motivational effects produced by sampling cocaine or exposure to drug-paired cues.
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Vallee N, Rostain JC, Risso JJ. A Pressurized Nitrogen Counterbalance to Cortical Glutamatergic Pathway Stimulation. Neurochem Res 2010; 35:718-26. [DOI: 10.1007/s11064-010-0125-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/12/2010] [Indexed: 10/19/2022]
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Kantrowitz J, Citrome L, Javitt D. GABA(B) receptors, schizophrenia and sleep dysfunction: a review of the relationship and its potential clinical and therapeutic implications. CNS Drugs 2009; 23:681-91. [PMID: 19594197 PMCID: PMC4988234 DOI: 10.2165/00023210-200923080-00005] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Evidence for an intrinsic relationship between sleep, cognition and the symptomatic manifestations of schizophrenia is accumulating. This review presents evidence for the possible utility of GABA(B) receptor agonists for the treatment of subjective and objective sleep abnormalities related to schizophrenia. At the phenotypic level, sleep disturbance occurs in 16-30% of patients with schizophrenia and is related to reduced quality of life and poor coping skills. On the neurophysiological level, studies suggest that sleep deficits reflect a core component of schizophrenia. Specifically, slow-wave sleep deficits, which are inversely correlated with cognition scores, are seen. Moreover, sleep plays an increasingly well documented role in memory consolidation in schizophrenia. Correlations of slow-wave sleep deficits with impaired reaction time and declarative memory have also been reported. Thus, both behavioural insomnia and sleep architecture are critical therapeutic targets in patients with schizophrenia. However, long-term treatment with antipsychotics often results in residual sleep dysfunction and does not improve slow-wave sleep, and adjunctive GABA(A) receptor modulators, such as benzodiazepines and zolpidem, can impair sleep architecture and cognition in schizophrenia. GABA(B) receptor agonists have therapeutic potential in schizophrenia. These agents have minimal effect on rapid eye movement sleep while increasing slow-wave sleep. Preclinical associations with increased expression of genes related to slow-wave sleep production and circadian rhythm function have also been reported. GABA(B) receptor deficits result in a sustained hyperdopaminergic state and can be reversed by a GABA(B) receptor agonist. Genetic, postmortem and electrophysiological studies also associate GABA(B) receptors with schizophrenia. While studies thus far have not shown significant effects, prior focus on the use of GABA(B) receptor agonists has been on the positive symptoms of schizophrenia, with minimal investigation of GABA(B) receptor agonists such as baclofen or gamma-hydroxybutyric acid and their effects on sleep architecture, cognition and negative symptoms in patients with schizophrenia. Further study is needed.
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Affiliation(s)
- Joshua Kantrowitz
- Nathan S. Kline Institute for Psychiatric Research, Orangeburg, New York, USA
| | - Leslie Citrome
- Nathan S. Kline Institute for Psychiatric Research, Orangeburg, New York, USA,Department of Psychiatry, New York University School of Medicine, New York, New York, USA
| | - Daniel Javitt
- Nathan S. Kline Institute for Psychiatric Research, Orangeburg, New York, USA,Department of Psychiatry, New York University School of Medicine, New York, New York, USA
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Prefrontal GABA(B) receptor activation attenuates phencyclidine-induced impairments of prepulse inhibition: involvement of nitric oxide. Neuropsychopharmacology 2009; 34:1673-84. [PMID: 19145229 DOI: 10.1038/npp.2008.225] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Recent theories propose that both GABA and glutamate signaling are compromised in patients with schizophrenia. These deficits can be observed in several brain regions including the prefrontal cortex (PFC), an area extensively linked to the cognitive dysfunction in this disease and notably affected by NMDA receptor antagonists such as phencyclidine (PCP). We have previously demonstrated that inhibition of the nitric oxide (NO) pathways in the brain, particularly in the PFC, prevents a wide range of PCP-induced behavioral deficits including disruption of prepulse inhibition (PPI). This study investigated the role of GABA(B) receptor signaling and NO in the effects of PCP on PPI. Mice received systemic or prefrontal injections of the GABA(B) receptor agonist baclofen (2.5-5 mg/kg and 1 mM) before PCP treatment (5 mg/kg) and were thereafter tested for PPI. GABA/NO interactions were studied by combining baclofen and the NO synthase inhibitor L-NAME (20 mg/kg) in subthreshold doses. The role of GABA(B) receptors for NO production in vivo was assessed using NO-sensors implanted into the rat PFC. PCP-induced PPI deficits were attenuated in an additive manner by systemic baclofen treatment, whereas prefrontal microinjections of baclofen completely blocked the effects of PCP, without affecting PPI per se. The combination of baclofen and L-NAME was more effective in preventing the effects of PCP than any compound by itself. Additionally, baclofen decreased NO release in the PFC in a dose-related manner. This study proposes a role for GABA(B) receptor signaling in the effects of PCP, with altered NO levels as a downstream consequence. Thus, prefrontal NO signaling mirrors an altered level of cortical inhibition that may be of importance for information processing deficits in schizophrenia.
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Abstract
Microdialysis is an in vivo sampling technique that permits the quantification of various substances (e.g., neurotransmitters, peptides, electrolytes) in blood and tissue. It is also used to infuse substances into the brain and spinal cord. This unit describes methods for the construction and stereotaxic implantation of microdialysis probes into discrete brain regions of the rat and mouse. Procedures for the conduct of conventional and quantitative microdialysis experiments in the awake and anesthetized rodent are also provided.
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Affiliation(s)
- Agustin Zapata
- Integrative Neuroscience Section, NIH/NIDA Intramural Research Program, Baltimore, Maryland, USA
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Wang F, Chen H, Sharp BM. Neuroadaptive changes in the mesocortical glutamatergic system during chronic nicotine self-administration and after extinction in rats. J Neurochem 2008; 106:943-56. [PMID: 18466321 DOI: 10.1111/j.1471-4159.2008.05456.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Nicotine self-administration causes adaptation in the mesocorticolimbic glutamatergic system, including the up-regulation of ionotropic glutamate receptor subunits. We therefore determined the effects of nicotine self-administration and extinction on NMDA-induced glutamate neurotransmission between the medial prefrontal cortex (mPFC) and ventral tegmental area (VTA). On day 19 of nicotine SA, both regions were microdialyzed for glutamate while mPFC was sequentially perfused with Kreb's Ringer buffer (KRB), 200 microM NMDA, KRB, 500 microM NMDA, KRB, and 100 mM KCl. Basal glutamate levels were unaffected, but nicotine self-administration significantly potentiated mPFC glutamate release to 200 microM NMDA, which was ineffective in controls. Furthermore, in VTA, nicotine self-administration significantly amplified glutamate responses to both mPFC infusions of NMDA. This hyper-responsive glutamate neurotransmission and enhanced glutamate subunit expression were reversed by extinction. Behavioral studies also showed that a microinjection of 2-amino-5-phosphonopentanoic acid (NMDA-R antagonist) into mPFC did not affect nicotine or sucrose self-administration. However, in VTA, NBQX (AMPA-R antagonist) attenuated both nicotine and sucrose self-administration. Collectively, these studies indicate that mesocortical glutamate neurotransmission adapts to chronic nicotine self-administration and VTA AMPA-R may be involved in the maintenance of nicotine self-administration.
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Affiliation(s)
- Fan Wang
- Department of Pharmacology, University of Tennessee Health Science Center, Memphis, Tennesse, USA
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Smith C, Bowery N, Whitehead K. GABA transporter type 1 (GAT-1) uptake inhibition reduces stimulated aspartate and glutamate release in the dorsal spinal cord in vivo via different GABAergic mechanisms. Neuropharmacology 2007; 53:975-81. [DOI: 10.1016/j.neuropharm.2007.09.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2007] [Revised: 09/19/2007] [Accepted: 09/24/2007] [Indexed: 10/22/2022]
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Bortolato M, Frau R, Orrù M, Piras AP, Fà M, Tuveri A, Puligheddu M, Gessa GL, Castelli MP, Mereu G, Marrosu F. Activation of GABA(B) receptors reverses spontaneous gating deficits in juvenile DBA/2J mice. Psychopharmacology (Berl) 2007; 194:361-9. [PMID: 17604981 DOI: 10.1007/s00213-007-0845-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2007] [Accepted: 05/30/2007] [Indexed: 10/23/2022]
Abstract
RATIONALE Gamma-amino-butyric acid (GABA)(B) receptors play a key role in the pathophysiology of psychotic disorders. We previously reported that baclofen, the prototypical GABA(B) agonist, elicits antipsychotic-like effects in the rat paradigm of prepulse inhibition (PPI) of the startle, a highly validated animal model of schizophrenia. OBJECTIVES We studied the role of GABA(B) receptors in the spontaneous PPI deficits displayed by DBA/2J mice. MATERIALS AND METHODS We tested the effects of baclofen (1.25-5 mg/kg, intraperitoneal [i.p.]) in DBA/2J and C57BL/6J mice, in comparison to the antipsychotic drugs haloperidol (1 mg/kg, i.p.) and clozapine (5 mg/kg, i.p.). Furthermore, we investigated the expression of GABA(B) receptors in the brain of DBA/2J and C57BL/6J mice by quantitative autoradiography. RESULTS Baclofen dose-dependently restored PPI deficit in DBA/2J mice, in a fashion similar to the antipsychotic clozapine (5 mg/kg, i.p.). This effect was reversed by pretreatment with the GABA(B) antagonist SCH50211 (50 mg/kg, i.p.). In contrast, baclofen did not affect PPI in C57BL/6J mice. Finally, quantitative autoradiographic analyses assessed a lower GABA(B) receptor expression in DBA/2J mice in comparison to C57BL/6J controls in the prefrontal cortex and hippocampus but not in other brain regions. CONCLUSIONS Our data highlight GABA(B) receptors as an important substrate for sensorimotor gating control in DBA/2J mice and encourage further investigations on the role of GABA(B) receptors in sensorimotor gating, as well as in the pathophysiology of psychotic disturbances.
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Affiliation(s)
- Marco Bortolato
- Department of Neuroscience "Bernard B. Brodie", University of Cagliari, Cittadella Universitaria, S.S.554 Km 4,500, 09042, Monserrato (CA), Italy.
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Bartoletti M, Ricci F, Gaiardi M. A GABA(B) agonist reverses the behavioral sensitization to morphine in rats. Psychopharmacology (Berl) 2007; 192:79-85. [PMID: 17242923 DOI: 10.1007/s00213-006-0693-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2006] [Accepted: 12/28/2006] [Indexed: 11/28/2022]
Abstract
RATIONALE In laboratory animals, repeated administration of drugs of abuse causes sensitization to their stimulant and rewarding effects. Neuroadaptations underlying sensitization could be related to those that contribute to addictive behaviors. An increased understanding of the molecular mechanisms of sensitization could lead to improved treatments for addiction. OBJECTIVES Since baclofen (BCF) co-administration has been reported to block the development and the expression of motor sensitization to morphine (MOR), the present study examined the hypothesis that a chronic treatment with BCF alone might reverse and/or prevent MOR-induced sensitization. METHODS Rats were first sensitized to MOR (saline or 10 mg/kg MOR i.p.; days 1-10) and then chronically treated with BCF (saline or 2 mg/kg BCF i.p.; days 11-20). Finally, the motility effect of MOR (10 mg/kg i.p.) was assessed 3 and 30 days after the end of BCF treatment. The same rats were again challenged with MOR on day 70, after a further period of saline or MOR treatment (days 51-60). RESULTS Behavioral sensitization to MOR was observed in control animals but not in rats chronically treated with BCF (days 23 and 50). Thus, BCF completely reversed MOR-induced sensitization, and its effect was long lasting. However, a previous repeated BCF treatment did not prevent the development of sensitization to MOR both in naive and desensitized rats. CONCLUSIONS The present results confirm that gamma-aminobutyric acid (GABA)(B) receptors play an important role in the expression of motor sensitization to MOR and suggest that GABA(B) agonists could be useful for reversing the neuroadaptations related to drug addiction.
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Affiliation(s)
- Maria Bartoletti
- Department of Pharmacology, University of Bologna, Via Irnerio 48, 40126, Bologna, Italy.
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Liu S, Bubar MJ, Lanfranco MF, Hillman GR, Cunningham KA. Serotonin2C receptor localization in GABA neurons of the rat medial prefrontal cortex: implications for understanding the neurobiology of addiction. Neuroscience 2007; 146:1677-88. [PMID: 17467185 PMCID: PMC2913252 DOI: 10.1016/j.neuroscience.2007.02.064] [Citation(s) in RCA: 118] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2006] [Revised: 01/31/2007] [Accepted: 02/15/2007] [Indexed: 10/23/2022]
Abstract
Serotonin (5-HT) action via the 5-HT(2C) receptor (5-HT(2C)R) provides an important modulatory influence over neurons of the prefrontal cortex (PFC), which is critically involved in disorders of executive function including substance use disorders. In the present study, we investigated the distribution of the 5-HT(2C)R in the rat prelimbic prefrontal cortex (PrL), a subregion of the medial prefrontal cortex (mPFC), using a polyclonal antibody raised against the 5-HT(2C)R. The expression of 5-HT(2C)R immunoreactivity (IR) was highest in the deep layers (layers V/VI) of the mPFC. The 5-HT(2C)R-IR was typically most intense at the periphery of cell bodies and the initial segment of cell processes. Approximately 50% of the 5-HT(2C)R-IR detected was found in glutamate decarboxylase, isoform 67 (GAD 67)-positive neurons. Of the subtypes of GABA interneurons identified by expression of several calcium-binding proteins, a significantly higher percentage of neurons expressing IR for parvalbumin also expressed 5-HT(2C)R-IR than did the percentage of neurons expressing calbindin-IR or calretinin-IR that also expressed 5-HT(2C)R-IR. Since parvalbumin is located in basket and chandelier GABA interneurons which project to cell body and initial axon segments of pyramidal cells, respectively, these results raise the possibility that the 5-HT(2C)R in the mPFC acts via the parvalbumin-positive GABAergic interneurons to regulate the output of pyramidal cells in the rat mPFC.
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Affiliation(s)
- S Liu
- Center for Addiction Research, Department of Pharmacology and Toxicology, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77555-1031, USA
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Takita M, Kuramochi M, Izaki Y, Ohtomi M. In vivo temporal property of GABAergic neural transmission in collateral feed-forward inhibition system of hippocampal-prefrontal pathway. Brain Res 2007; 1150:69-73. [PMID: 17382915 DOI: 10.1016/j.brainres.2007.02.063] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2006] [Revised: 02/20/2007] [Accepted: 02/23/2007] [Indexed: 11/23/2022]
Abstract
Anatomical evidence suggests that rat CA1 hippocampal afferents collaterally innervate excitatory projecting pyramidal neurons and inhibitory interneurons, creating a disynaptic, feed-forward inhibition microcircuit in the medial prefrontal cortex (mPFC). We investigated the temporal relationship between the frequency of paired synaptic transmission and gamma-aminobutyric acid (GABA)ergic receptor-mediated modulation of the microcircuit in vivo under urethane anesthesia. Local perfusions of a GABAa antagonist (-)-bicuculline into the mPFC via microdialysis resulted in a statistically significant disinhibitory effect on intrinsic GABA action, increasing the first and second mPFC responses following hippocampal paired stimulation at interstimulus intervals of 100-200 ms, but not those at 25-50 ms. This (-)-bicuculline-induced disinhibition was compensated by the GABAa agonist muscimol, which itself did not attenuate the intrinsic oscillation of the local field potentials. The perfusion of a sub-minimal concentration of GABAb agonist (R)-baclofen slightly enhanced the synaptic transmission, regardless of the interstimulus interval. In addition to the tonic control by spontaneous fast-spiking GABAergic neurons, it is clear the sequential transmission of the hippocampal-mPFC pathway can phasically drive the collateral feed-forward inhibition system through activation of a GABAa receptor, bringing an active signal filter to the various types of impulse trains that enter the mPFC from the hippocampus in vivo.
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Affiliation(s)
- Masatoshi Takita
- Cognition and Action Group, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8566, Japan.
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Suzuki T, Nurrochmad A, Ozaki M, Khotib J, Nakamura A, Imai S, Shibasaki M, Yajima Y, Narita M. Effect of a selective GABAB receptor agonist baclofen on the μ-opioid receptor agonist-induced antinociceptive, emetic and rewarding effects. Neuropharmacology 2005; 49:1121-31. [PMID: 16095635 DOI: 10.1016/j.neuropharm.2005.06.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2005] [Revised: 06/13/2005] [Accepted: 06/14/2005] [Indexed: 10/25/2022]
Abstract
The management of excessive adverse effects of opioids is a major clinical problem. The present study was undertaken to investigate the effect of a selective gamma-aminobutyric acid (GABA)(B) receptor agonist baclofen on the mu-opioid receptor agonist-induced antinociceptive, emetic and rewarding effects. Either morphine or fentanyl produced a dose-dependent antinociceptive effect in both ferrets using Randall-Selitto test and mice using tail-flick test. Under these conditions, pretreatment of baclofen produced an additive antinociception induced by morphine or fentanyl. Furthermore, the augmentation of antinociception induced by systemic administration of baclofen with morphine or fentanyl was completely abolished by either i.c.v. or i.t. pretreatment with the selective GABA(B) receptor antagonist CGP 35348 in mice. We next investigated the emetic response induced by mu-opioid receptor agonist in ferrets. Morphine at lower doses than that used for antinociceptive assay produced both retching and vomiting, whereas fentanyl failed to produce the retching and vomiting in ferrets. Here we reported for the first time that baclofen significantly suppressed the retching and vomiting induced by morphine, indicating the involvement of GABA(B) receptor in emetic control pathway. Furthermore, baclofen also inhibited place preference elicited morphine or fentanyl in rats. Taken together, these results suggest that co-administration of baclofen with mu-opioid receptor agonist produced a potentiation of antinociceptive effect, whereas an untoward effect was completely blocked.
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Affiliation(s)
- Tsutomu Suzuki
- Department of Toxicology, Hoshi University School of Pharmacy and Pharmaceutical Sciences, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan.
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Bartoletti M, Gubellini C, Ricci F, Gaiardi M. Baclofen blocks the development of sensitization to the locomotor stimulant effect of amphetamine. Behav Pharmacol 2005; 16:553-8. [PMID: 16170232 DOI: 10.1097/01.fbp.0000179279.98029.e9] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The GABAB agonist baclofen (BCF) has recently been reported to block the expression of sensitization to the locomotor effect of amphetamine (AMPH), and to reverse it after repeated administration. The present study was undertaken to investigate whether baclofen could also prevent the development of sensitization to the psychostimulant. Chronic AMPH treatment (1.5 mg/kg i.p. for 10 days) led to an increased locomotor response to AMPH (1.5 mg/kg) when the animals were challenged 3 and 30 days after the end of repeated treatment. Chronic co-administration of BCF (2 mg/kg, i.p.) and AMPH blocked the development of sensitization to the stimulant effect of AMPH. An ancillary experiment excluded that a 'state-dependency' hypothesis could account for the effect of baclofen. Furthermore, a previous repeated treatment with baclofen alone had no influence either on the acute AMPH effect or on the subsequent development of sensitization to AMPH. In conclusion, the results confirm that GABAB receptors play an important role in the acquisition of AMPH behavioural sensitization and further support a potential use of GABAB agonists in the treatment of psychostimulant addiction.
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Affiliation(s)
- M Bartoletti
- Department of Pharmacology, University of Bologna, Via Irnerio 48, I-40126 Bologna, Italy.
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