1
|
Peczely L, Ollmann T, Laszlo K, Lenard L, Grace AA. The D2-like Dopamine Receptor Agonist Quinpirole Microinjected Into the Ventral Pallidum Dose-Dependently Inhibits the VTA and Induces Place Aversion. Int J Neuropsychopharmacol 2022; 25:590-599. [PMID: 35348731 PMCID: PMC9352176 DOI: 10.1093/ijnp/pyac024] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 03/01/2022] [Accepted: 03/25/2022] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND The ventral pallidum (VP) is a dopaminoceptive forebrain structure regulating the ventral tegmental area (VTA) dopaminergic population activity. We have recently demonstrated that in the VP, the D2-like dopamine (DA) receptor agonist quinpirole dose dependently facilitates memory consolidation in inhibitory avoidance and spatial learning. According to our hypothesis, quinpirole microinjected into the VP can modulate the VTA DAergic activity and influence motivation and learning processes of rats. METHODS Quinpirole was microinjected at 3 different doses into the VP of male rats, and controls received vehicle. Single unit recordings were employed to assess VTA DAergic activity. To investigate the possible reinforcing or aversive effect of quinpirole in the VP, the conditioned place preference paradigm was used. RESULTS Our results showed that intra-VP quinpirole microinjection regulates VTA DAergic neurons according to an inverted U-shaped dose-response curve. The largest dose of quinpirole decreased the population activity and strongly reduced burst activity of the DAergic neurons in the first hour after its application. In contrast, the 2 smaller doses increased DA population activity, but their effect started with a delay 1 hour after their microinjection. The CPP experiments revealed that the largest dose of quinpirole in the VP induced place aversion in the rats. Furthermore, the largest dose of quinpirole induced an acute locomotor activity reduction, while the medium dose led to a long-duration increase in locomotion. CONCLUSIONS In summary, quinpirole dose dependently regulates VTA DAergic activity as well as the motivation and motor behavior of the rats at the level of the VP.
Collapse
Affiliation(s)
- Laszlo Peczely
- Correspondence: Laszlo Peczely, MD, PhD, Institute of Physiology, Faculty of Medicine, University of Pécs, PO Box 99, H-7602 Pécs, Hungary, Szigeti str. 12 ()
| | - Tamas Ollmann
- Learning in Biological and Artificial Systems Research Group, Institute of Physiology, Pittsburgh, PA, USA,Neuropeptides, Cognition, Animal Models of Neuropsychiatric Disorders Research Group, Institute of Physiology, Pecs, Hungary,Medical School, University of Pecs, Pecs, Hungary,Centre for Neuroscience, Pecs, Hungary,University of Pecs, Pecs, Hungary
| | - Kristof Laszlo
- Neuropeptides, Cognition, Animal Models of Neuropsychiatric Disorders Research Group, Institute of Physiology, Pecs, Hungary,Medical School, University of Pecs, Pecs, Hungary,Centre for Neuroscience, Pecs, Hungary,University of Pecs, Pecs, Hungary
| | - Laszlo Lenard
- Learning in Biological and Artificial Systems Research Group, Institute of Physiology, Pittsburgh, PA, USA,Molecular Neuroendocrinology and Neurophysiology Research Group, Szentagothai Research Centre, Pecs, Hungary
| | - Anthony A Grace
- Departments of Neuroscience, Psychiatry and Psychology, University of Pittsburgh, Pittsburgh, PA, USA
| |
Collapse
|
2
|
Watanabe T, Sasaki K. Regulation of dopamine production in the brains during sexual maturation in male honey bees. JOURNAL OF INSECT PHYSIOLOGY 2021; 132:104270. [PMID: 34175313 DOI: 10.1016/j.jinsphys.2021.104270] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 05/30/2021] [Accepted: 06/21/2021] [Indexed: 06/13/2023]
Abstract
To explore the physiological mechanisms that underlie age-related dopamine increases during sexual maturation in the brains of male honey bees, we focused on the expression of genes encoding the enzymes tyrosine hydroxylase (Amth) and DOPA decarboxylase (Amddc), which are involved in dopamine biosynthesis in the brain. We hypothesized that juvenile hormone in hemolymph and tyrosine intake from food known as factors enhancing brain dopamine levels might both control the expression of genes related to dopamine production, and we tested this hypothesis in experiments. The brain levels of tyrosine and DOPA, which are precursors of dopamine, decreased as males aged, whereas the dopamine levels increased, suggesting active metabolism of dopamine precursors. The relative expression levels of Amth and Amddc were significantly higher in the brains of 4-day-old males compared with 0-day-old males, and the higher level of Amddc was maintained after 8 days. Topical application of the juvenile hormone analog methoprene enhanced the expression levels of Amth and Amddc in the brains according to the methoprene concentration. Oral intake of tyrosine enhanced the tyrosine, DOPA and dopamine levels in the brain, and activated Amddc expression in the brain, suggesting that tyrosine intake can increase both substrates and enzyme for dopamine biosynthesis. These results support our hypothesis that juvenile hormone and tyrosine intake may enhance the expression levels of genes encoding enzymes involved in dopamine biosynthesis in male honey bee brains during sexual maturation.
Collapse
Affiliation(s)
- Tomohiro Watanabe
- Graduate School of Agriculture, Tamagawa University, Machida, Tokyo 194-8610, Japan
| | - Ken Sasaki
- Graduate School of Agriculture, Tamagawa University, Machida, Tokyo 194-8610, Japan.
| |
Collapse
|
3
|
Differential Impact of Inhibitory G-Protein Signaling Pathways in Ventral Tegmental Area Dopamine Neurons on Behavioral Sensitivity to Cocaine and Morphine. eNeuro 2021; 8:ENEURO.0081-21.2021. [PMID: 33707203 PMCID: PMC8114902 DOI: 10.1523/eneuro.0081-21.2021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 03/03/2021] [Indexed: 12/21/2022] Open
Abstract
Drugs of abuse engage overlapping but distinct molecular and cellular mechanisms to enhance dopamine (DA) signaling in the mesocorticolimbic circuitry. DA neurons of the ventral tegmental area (VTA) are key substrates of drugs of abuse and have been implicated in addiction-related behaviors. Enhanced VTA DA neurotransmission evoked by drugs of abuse can engage inhibitory G-protein-dependent feedback pathways, mediated by GABAB receptors (GABABRs) and D2 DA receptors (D2Rs). Chemogenetic inhibition of VTA DA neurons potently suppressed baseline motor activity, as well as the motor-stimulatory effect of cocaine and morphine, confirming the critical influence of VTA DA neurons and inhibitory G-protein signaling in these neurons on this addiction-related behavior. To resolve the relative influence of GABABR-dependent and D2R-dependent signaling pathways in VTA DA neurons on behavioral sensitivity to drugs of abuse, we developed a neuron-specific viral CRISPR/Cas9 approach to ablate D2R and GABABR in VTA DA neurons. Ablation of GABABR or D2R did not impact baseline physiological properties or excitability of VTA DA neurons, but it did preclude the direct somatodendritic inhibitory influence of GABABR or D2R activation. D2R ablation potentiated the motor-stimulatory effect of cocaine in male and female mice, whereas GABABR ablation selectively potentiated cocaine-induced activity in male subjects only. Neither D2R nor GABABR ablation impacted morphine-induced motor activity. Collectively, our data show that cocaine and morphine differ in the extent to which they engage inhibitory G-protein-dependent feedback pathways in VTA DA neurons and highlight key sex differences that may impact susceptibility to various facets of addiction.
Collapse
|
4
|
Chetia S, Borah G. Δ 9-Tetrahydrocannabinol Toxicity and Validation of Cannabidiol on Brain Dopamine Levels: An Assessment on Cannabis Duplicity. NATURAL PRODUCTS AND BIOPROSPECTING 2020; 10:285-296. [PMID: 32860199 PMCID: PMC7520491 DOI: 10.1007/s13659-020-00263-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 08/23/2020] [Indexed: 06/11/2023]
Abstract
Δ9-tetrahydrocannabinol (THC) of cannabis is the main psychoactive component which is a global significant concern to human health. Evaluation on THC reported its drastic effect on the brain dopaminergic (DAergic) system stimulating mesolimbic DA containing neurons thereby increasing the level of striatal DA. Cannabidiol (CBD), with its anxiolytic and anti-psychotic property, is potent to ameliorate the THC-induced DAergic variations. Legal authorization of cannabis use and its analogs in most countries led to a drastic dispute in the elicitation of cannabis products. With a recent increase in cannabis-induced disorder rates, the present review highlighted the detrimental effects of THC and the effects of CBD on THC induced alterations in DA synthesis and release. Alongside the reported data, uses of cannabis as a therapeutic medium in a number of health complications are also being briefly reviewed. These evaluated reports led to an anticipation of additional research contradictory to the findings of THC and CBD activity in the brain DAergic system and their medical implementations as therapeutics.
Collapse
Affiliation(s)
- Swapnali Chetia
- Department of Zoology, Rajiv Gandhi University, Rono Hills, Doimukh, Arunachal Pradesh, 791112, India.
| | - Gaurab Borah
- Department of Zoology, Rajiv Gandhi University, Rono Hills, Doimukh, Arunachal Pradesh, 791112, India
| |
Collapse
|
5
|
Rosa HZ, Segat HJ, Barcelos RCS, Roversi K, Rossato DR, de Brum GF, Burger ME. Involvement of the endogenous opioid system in the beneficial influence of physical exercise on amphetamine-induced addiction parameters. Pharmacol Biochem Behav 2020; 197:173000. [PMID: 32702398 DOI: 10.1016/j.pbb.2020.173000] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 05/31/2020] [Accepted: 07/16/2020] [Indexed: 12/21/2022]
Abstract
Psychostimulant drugs addiction is a chronic public health problem and individuals remain susceptible to relapses increasing public expenses even after withdrawal and treatment. Our research group has focused on finding new therapies to be employed in drug addiction treatment, suggesting the physical exercise as a promising tool. This way, it is necessary to know the mechanisms involved in the beneficial influences of physical exercise observing the pathway that could be explored in drug addiction treatment. Male Wistar rats were conditioned with amphetamine (AMPH) following the conditioned place preference (CPP) protocol and subsequently submitted to swimming for 5 weeks (1 h per day, 5 days per week). Half of the animals were injected with Naloxone (0.3 mg/mL/kg body weight, i.p.) 5 min prior each physical exercise day. After AMPH-CPP re-exposure, our outcomes showed that physical exercise, in addition to minimizing the relapse behavior in the CPP, it increased D1R, D2R and DAT in the Ventral Tegmental Area (VTA), but not in the Nucleus accumbens (NAc). Interestingly, while naloxone inhibited the partial beneficial influence of the exercise on drug-relapse behavior, exercise-induced changes in the dopaminergic system were not observed in the group administered with naloxone as well. Based on these evidences, besides reinforcing the beneficial influence of the physical exercise on AMPH-induced drug addiction, we propose the involvement of endogenous opioid system activation, not as a single one, but as a possible mechanism of action resulting from the physical activity practice, thus characterizing an important therapeutic approach, which may contribute to drug withdrawal consequently preventing relapse.
Collapse
Affiliation(s)
- H Z Rosa
- Programa de Pós-Graduação em Farmacologia, Universidade Federal de Santa Maria - UFSM, Santa Maria, RS, Brazil
| | - H J Segat
- Departamento de Patologia, Universidade Federal de Santa Maria - UFSM, Santa Maria, RS, Brazil
| | - R C S Barcelos
- Programa de Pós-Graduação em Farmacologia, Universidade Federal de Santa Maria - UFSM, Santa Maria, RS, Brazil
| | - Kr Roversi
- Programa de Pós-Graduação em Farmacologia, Universidade Federal de Santa Maria - UFSM, Santa Maria, RS, Brazil
| | - D R Rossato
- Departamento de Fisiologia e Farmacologia, Universidade Federal de Santa Maria - UFSM, Santa Maria, RS, Brazil
| | - G F de Brum
- Programa de Pós-Graduação em Farmacologia, Universidade Federal de Santa Maria - UFSM, Santa Maria, RS, Brazil
| | - M E Burger
- Programa de Pós-Graduação em Farmacologia, Universidade Federal de Santa Maria - UFSM, Santa Maria, RS, Brazil; Departamento de Patologia, Universidade Federal de Santa Maria - UFSM, Santa Maria, RS, Brazil; Departamento de Fisiologia e Farmacologia, Universidade Federal de Santa Maria - UFSM, Santa Maria, RS, Brazil.
| |
Collapse
|
6
|
Silkstone M, Brudzynski SM. Dissimilar interaction between dopaminergic and cholinergic systems in the initiation of emission of 50-kHz and 22-kHz vocalizations. Pharmacol Biochem Behav 2020; 188:172815. [DOI: 10.1016/j.pbb.2019.172815] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 09/09/2019] [Accepted: 10/15/2019] [Indexed: 10/25/2022]
|
7
|
Sampedro-Piquero P, J. Santín L, Castilla-Ortega E. Aberrant Brain Neuroplasticity and Function in Drug Addiction: A Focus on Learning-Related Brain Regions. Behav Neurosci 2019. [DOI: 10.5772/intechopen.85280] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
8
|
Fitoussi A, Zunder J, Tan H, Laviolette SR. Delta-9-tetrahydrocannabinol potentiates fear memory salience through functional modulation of mesolimbic dopaminergic activity states. Eur J Neurosci 2019; 47:1385-1400. [PMID: 29776015 DOI: 10.1111/ejn.13951] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 04/03/2018] [Accepted: 04/12/2018] [Indexed: 01/14/2023]
Abstract
Chronic or acute exposure to delta-9-tetrahydrocannabinol (THC), the main psychoactive compound in cannabis, has been associated with numerous neuropsychiatric side-effects, including dysregulation of emotional processing and associative memory formation. Clinical and preclinical evidence suggests that the effects of THC are due to the ability to modulate mesolimbic dopamine (DA) activity states in the nucleus accumbens (NAc) and ventral tegmental area (VTA). Nevertheless, the mechanisms by which THC modulates mesolimbic DA function and emotional processing are not well understood. Using an olfactory associative fear memory procedure combined with in vivo neuronal electrophysiology, we examined the effects of direct THC microinfusions targeting the shell region of the NAc (NASh) and examined how THC may modulate the processing of fear-related emotional memory and concomitant activity states of the mesolimbic DA system. We report that intra-NASh THC dose-dependently potentiates the emotional salience of normally subthreshold fear conditioning cues. These effects were dependent upon intra-VTA transmission through GABAergic receptor mechanisms and intra-NASh DAergic transmission. Furthermore, doses of intra-NASh THC that potentiated fear memory salience were found to modulate intra-VTA neuronal network activity by increasing the spontaneous firing and bursting frequency of DAergic neurones whilst decreasing the activity levels of a subpopulation of putative GABAergic VTA neurones. These findings demonstrate that THC can act directly in the NASh to modulate mesolimbic activity states and induce disturbances in emotional salience and memory formation through modulation of VTA DAergic transmission.
Collapse
Affiliation(s)
- Aurelie Fitoussi
- Addiction Research Group, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada.,Department of Anatomy & Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada
| | - Jordan Zunder
- Addiction Research Group, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada.,Department of Anatomy & Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada
| | - Huibing Tan
- Addiction Research Group, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada.,Department of Anatomy & Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada
| | - Steven R Laviolette
- Addiction Research Group, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada.,Department of Anatomy & Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada.,Department of Psychiatry, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada
| |
Collapse
|
9
|
Wang W, Zeng F, Hu Y, Li X. A Mini-Review of the Role of Glutamate Transporter in Drug Addiction. Front Neurol 2019; 10:1123. [PMID: 31695674 PMCID: PMC6817614 DOI: 10.3389/fneur.2019.01123] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 10/08/2019] [Indexed: 12/29/2022] Open
Abstract
Goals: The development of new treatment for drug abuse requires identification of targetable molecular mechanisms. The pathology of glutamate neurotransmission system in the brain reward circuit is related to the relapse of multiple drugs. Glutamate transporter regulates glutamate signaling by removing excess glutamate from the synapse. And the mechanisms between glutamate transporter and drug addiction are still unclear. Methods: A systematic review of the literature searched in Pubmed and reporting drug addiction in relation to glutamate transporter. Studies were screened by title, abstract, and full text. Results: This review is to highlight the effects of drug addiction on glutamate transporter and glutamate uptake, and targeting glutamate transporter as an addictive drug addiction treatment. We focus on the roles of glutamate transporter in different brain regions in drug addiction. More importantly, we suggest the functional roles of glutamate transporter may prove beneficial in the treatment of drug addiction. Conclusion: Overall, understanding how glutamate transporter impacts central nervous system may provide a new insight for treatment of drug addiction.
Collapse
Affiliation(s)
- Wenjun Wang
- Institute for Cancer Medicine and School of Basic Medical Sciences, Southwest Medical University, Luzhou, China
| | - Fancai Zeng
- Department of Biochemistry and Molecular Biology, School of Basic Medical Science, Southwest Medical University, Luzhou, China
| | - Yingying Hu
- Department of Biochemistry and Molecular Biology, School of Basic Medical Science, Southwest Medical University, Luzhou, China
| | - Xiang Li
- Department of Biochemistry and Molecular Biology, School of Basic Medical Science, Southwest Medical University, Luzhou, China
| |
Collapse
|
10
|
Sasaki K, Ugajin A, Harano KI. Caste-specific development of the dopaminergic system during metamorphosis in female honey bees. PLoS One 2018; 13:e0206624. [PMID: 30372493 PMCID: PMC6205643 DOI: 10.1371/journal.pone.0206624] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 10/16/2018] [Indexed: 01/02/2023] Open
Abstract
Caste-specific differences in the dopaminergic systems of social insects assist in maintaining caste-specific behavior. To determine how caste differences in the honey bee occur during metamorphosis, a number of comparative analyses between castes were performed including comprehensive quantification of: levels of dopamine and its metabolite in the brain, the gene expression levels of enzymes involved in dopamine biosynthesis and conversion as well as expression levels of dopamine receptors and a dopamine transporter. Dopamine levels standardized to the protein contents of a whole brain at the day of eclosion in queens were 3.6-fold higher than those in workers. Dopamine levels increased until eclosion (7 days) in queens, whereas those in workers increased until 5–6 days before eclosion and then maintained until eclosion (10 days). These caste-specific dopamine dynamics in the brain were supported by the higher expression of genes (Amddc and Amth) encoding enzymes involved in dopamine synthesis in queens. The distribution of cells expressing Amddc in the brain revealed that soma clusters of dopaminergic cells were similar between castes at 7–8 days after pupation, suggesting the upregulation of Amddc expression in some cells in queens rather than addition of cell clusters. In contrast, genes encoding dopamine receptors were downregulated in queens or showed similar expression levels between castes. The expression of genes encoding dopamine transporters did not differ between castes. These results reveal the developmental process of caste-specific dopaminergic systems during metamorphosis in the honey bee, suggesting caste-specific behavior and division of reproduction in this highly eusocial species.
Collapse
Affiliation(s)
- Ken Sasaki
- Graduate School of Agriculture, Tamagawa University, Machida, Tokyo, Japan
- * E-mail:
| | - Atsushi Ugajin
- Graduate School of Agriculture, Tamagawa University, Machida, Tokyo, Japan
| | - Ken-ichi Harano
- Graduate School of Agriculture, Tamagawa University, Machida, Tokyo, Japan
| |
Collapse
|
11
|
You C, Vandegrift BJ, Zhang H, Lasek AW, Pandey SC, Brodie MS. Histone Deacetylase Inhibitor Suberanilohydroxamic Acid Treatment Reverses Hyposensitivity to γ-Aminobutyric Acid in the Ventral Tegmental Area During Ethanol Withdrawal. Alcohol Clin Exp Res 2018; 42:2160-2171. [PMID: 30103280 PMCID: PMC6214766 DOI: 10.1111/acer.13870] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 08/08/2018] [Indexed: 12/24/2022]
Abstract
Background The ventral tegmental area (VTA) is important for alcohol‐related reward and reinforcement. Mouse VTA neurons are hyposensitive to γ‐aminobutyric acid (GABA) during ethanol (EtOH) withdrawal, and GABA responsiveness is normalized by in vitro treatment with histone deacetylase inhibitors (HDACi). The present study examined the effect of a systemically administered HDACi, suberanilohydroxamic acid (SAHA) on GABA sensitivity, and related molecular changes in VTA neurons during withdrawal after chronic EtOH intake in rats. Methods Sprague Dawley male adult rats were fed with Lieber‐DeCarli diet (9% EtOH or control diet) for 16 days. Experimental groups included control diet‐fed and EtOH diet‐fed (0‐ or 24‐hour withdrawal) rats treated with either SAHA or vehicle injection. Single‐unit recordings were used to measure the response of VTA neurons to GABA. Immunohistochemistry was performed to examine levels of HDAC2, acetylated histone H3 lysine 9 (acH3K9), and GABAA receptor α1 and α5 subunits in the VTA; quantitative polymerase chain reaction was performed to examine the mRNA levels of HDAC2 and GABAA receptor subunits. Results VTA neurons from the withdrawal group exhibited GABA hyposensitivity. In vivo SAHA treatment 2 hours before sacrifice normalized the sensitivity of VTA neurons to GABA. EtOH withdrawal was associated with increased HDAC2 and decreased acH3K9 protein levels; SAHA treatment normalized acH3K9 levels. Interestingly, no significant change was observed in the mRNA levels of HDAC2. The mRNA levels, but not protein levels, of GABAA receptor α1 and α5 subunits were increased during withdrawal. Conclusions Withdrawal from chronic EtOH exposure results in a decrease in GABA‐mediated inhibition, and this GABA hyposensitivity is normalized by in vivo SAHA treatment. Disruption of signaling in the VTA produced by alteration of GABA neurotransmission could be 1 neuroadaptive physiological process leading to craving and relapse. These results suggest that HDACi pharmacotherapy with agents like SAHA might be an effective treatment for alcoholism.
Collapse
Affiliation(s)
- Chang You
- Department of Physiology and Biophysics , University of Illinois at Chicago, Chicago, Illinois.,Center for Alcohol Research in Epigenetics , Department of Psychiatry, University of Illinois at Chicago, Chicago, Illinois
| | - Bertha J Vandegrift
- Department of Physiology and Biophysics , University of Illinois at Chicago, Chicago, Illinois.,Center for Alcohol Research in Epigenetics , Department of Psychiatry, University of Illinois at Chicago, Chicago, Illinois
| | - Huaibo Zhang
- Center for Alcohol Research in Epigenetics , Department of Psychiatry, University of Illinois at Chicago, Chicago, Illinois.,Jesse Brown VA Medical Center , Chicago, Illinois
| | - Amy W Lasek
- Center for Alcohol Research in Epigenetics , Department of Psychiatry, University of Illinois at Chicago, Chicago, Illinois
| | - Subhash C Pandey
- Center for Alcohol Research in Epigenetics , Department of Psychiatry, University of Illinois at Chicago, Chicago, Illinois.,Jesse Brown VA Medical Center , Chicago, Illinois
| | - Mark S Brodie
- Department of Physiology and Biophysics , University of Illinois at Chicago, Chicago, Illinois.,Center for Alcohol Research in Epigenetics , Department of Psychiatry, University of Illinois at Chicago, Chicago, Illinois
| |
Collapse
|
12
|
You C, Vandegrift B, Brodie MS. Ethanol actions on the ventral tegmental area: novel potential targets on reward pathway neurons. Psychopharmacology (Berl) 2018; 235:1711-1726. [PMID: 29549390 PMCID: PMC5949141 DOI: 10.1007/s00213-018-4875-y] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 03/06/2018] [Indexed: 12/14/2022]
Abstract
The ventral tegmental area (VTA) evaluates salience of environmental stimuli and provides dopaminergic innervation to many brain areas affected by acute and chronic ethanol exposure. While primarily associated with rewarding and reinforcing stimuli, recent evidence indicates a role for the VTA in aversion as well. Ethanol actions in the VTA may trigger neuroadaptation resulting in reduction of the aversive responses to alcohol and a relative increase in the rewarding responses. In searching for effective pharmacotherapies for the treatment of alcohol abuse and alcoholism, recognition of this imbalance may reveal novel strategies. In addition to conventional receptor/ion channel pharmacotherapies, epigenetic factors that control neuroadaptation to chronic ethanol treatment can be targeted as an avenue for development of therapeutic approaches to restore the balance. Furthermore, when exploring therapies to address reward/aversion imbalance in the action of alcohol in the VTA, sex differences have to be taken into account to ensure effective treatment for both men and women. These principles apply to a VTA-centric approach to therapies, but should hold true when thinking about the overall approach in the development of neuroactive drugs to treat alcohol use disorders. Although the functions of the VTA itself are complex, it is a useful model system to evaluate the reward/aversion imbalance that occurs with ethanol exposure and could be used to provide new leads in the efforts to develop novel drugs to treat alcoholism.
Collapse
Affiliation(s)
- Chang You
- Department of Physiology and Biophysics, University of Illinois at Chicago, 835 S. Wolcott Ave, Room E-202, M/C 901, Chicago, IL, 60612, USA
- Center for Alcohol Research in Epigenetics, Department of Psychiatry, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | - Bertha Vandegrift
- Department of Physiology and Biophysics, University of Illinois at Chicago, 835 S. Wolcott Ave, Room E-202, M/C 901, Chicago, IL, 60612, USA
- Center for Alcohol Research in Epigenetics, Department of Psychiatry, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | - Mark S Brodie
- Department of Physiology and Biophysics, University of Illinois at Chicago, 835 S. Wolcott Ave, Room E-202, M/C 901, Chicago, IL, 60612, USA.
- Center for Alcohol Research in Epigenetics, Department of Psychiatry, University of Illinois at Chicago, Chicago, IL, 60612, USA.
| |
Collapse
|
13
|
Bergamini G, Mechtersheimer J, Azzinnari D, Sigrist H, Buerge M, Dallmann R, Freije R, Kouraki A, Opacka-Juffry J, Seifritz E, Ferger B, Suter T, Pryce CR. Chronic social stress induces peripheral and central immune activation, blunted mesolimbic dopamine function, and reduced reward-directed behaviour in mice. Neurobiol Stress 2018; 8:42-56. [PMID: 29888303 PMCID: PMC5991330 DOI: 10.1016/j.ynstr.2018.01.004] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 12/19/2017] [Accepted: 01/31/2018] [Indexed: 12/19/2022] Open
Abstract
Psychosocial stress is a major risk factor for depression, stress leads to peripheral and central immune activation, immune activation is associated with blunted dopamine (DA) neural function, DA function underlies reward interest, and reduced reward interest is a core symptom of depression. These states might be inter-independent in a complex causal pathway. Whilst animal-model evidence exists for some specific steps in the pathway, there is currently no animal model in which it has been demonstrated that social stress leads to each of these immune, neural and behavioural states. Such a model would provide important existential evidence for the complex pathway and would enable the study of causality and mediating mechanisms at specific steps in the pathway. Therefore, in the present mouse study we investigated for effects of 15-day resident-intruder chronic social stress (CSS) on each of these states. Relative to controls, CSS mice exhibited higher spleen levels of granulocytes, inflammatory monocytes and T helper 17 cells; plasma levels of inducible nitric oxide synthase; and liver expression of genes encoding kynurenine pathway enzymes. CSS led in the ventral tegmental area to higher levels of kynurenine and the microglia markers Iba1 and Cd11b and higher binding activity of DA D1 receptor; and in the nucleus accumbens (NAcc) to higher kynurenine, lower DA turnover and lower c-fos expression. Pharmacological challenge with DA reuptake inhibitor identified attenuation of DA stimulatory effects on locomotor activity and NAcc c-fos expression in CSS mice. In behavioural tests of operant responding for sucrose reward validated as sensitive assays for NAcc DA function, CSS mice exhibited less reward-directed behaviour. Therefore, this mouse study demonstrates that a chronic social stressor leads to changes in each of the immune, neural and behavioural states proposed to mediate between stress and disruption of DA-dependent reward processing. The model can now be applied to investigate causality and, if demonstrated, underlying mechanisms in specific steps of this immune-neural-behavioural pathway, and thereby to identify potential therapeutic targets. Mouse chronic social stress (CSS) leads to spleen and liver immune activation. Mouse CSS leads to mesolimbic immune activation and blunted dopamine function. Mouse CSS leads to reduced reward-directed behaviour in operant tests. This constitutes an important model for the study of pathophysiological mechanisms.
Collapse
Affiliation(s)
- Giorgio Bergamini
- Preclinical Laboratory for Translational Research into Affective Disorders, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Switzerland.,Center for Clinical Studies, Vetsuisse Faculty, University of Zurich, Switzerland.,Neuroscience Center Zurich, University of Zurich and ETH Zurich, Switzerland
| | - Jonas Mechtersheimer
- Preclinical Laboratory for Translational Research into Affective Disorders, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Switzerland
| | - Damiano Azzinnari
- Preclinical Laboratory for Translational Research into Affective Disorders, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Switzerland.,Neuroscience Center Zurich, University of Zurich and ETH Zurich, Switzerland
| | - Hannes Sigrist
- Preclinical Laboratory for Translational Research into Affective Disorders, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Switzerland
| | - Michaela Buerge
- Preclinical Laboratory for Translational Research into Affective Disorders, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Switzerland.,Neuroscience Center Zurich, University of Zurich and ETH Zurich, Switzerland
| | - Robert Dallmann
- Warwick Medical School, University of Warwick, Coventry, United Kingdom
| | | | - Afroditi Kouraki
- Department of Life Sciences, University of Roehampton, London, UK
| | | | - Erich Seifritz
- Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Switzerland.,Neuroscience Center Zurich, University of Zurich and ETH Zurich, Switzerland
| | - Boris Ferger
- CNS Diseases Research Germany, Boehringer Ingelheim Pharma GmbH & Co. KG., Biberach, Germany
| | - Tobias Suter
- Neuroimmunology and MS Research, Neurology, and Clinical Research Priority Program Multiple Sclerosis, University Hospital Zurich, University of Zurich, Switzerland.,Neuroscience Center Zurich, University of Zurich and ETH Zurich, Switzerland
| | - Christopher R Pryce
- Preclinical Laboratory for Translational Research into Affective Disorders, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Switzerland.,Neuroscience Center Zurich, University of Zurich and ETH Zurich, Switzerland
| |
Collapse
|
14
|
Fujiwara T, Kofuji T, Mishima T, Akagawa K. Syntaxin 1B contributes to regulation of the dopaminergic system through GABA transmission in the CNS. Eur J Neurosci 2017; 46:2867-2874. [PMID: 29139159 DOI: 10.1111/ejn.13779] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 11/09/2017] [Accepted: 11/09/2017] [Indexed: 12/17/2022]
Abstract
In neuronal plasma membrane, two syntaxin isoforms, HPC-1/syntaxin 1A (STX1A) and syntaxin 1B (STX1B), are predominantly expressed as soluble N-ethylmaleimide-sensitive fusion attachment protein receptors, also known as t-SNAREs. We previously reported that glutamatergic and GABAergic synaptic transmissions are impaired in Stx1b null mutant (Stx1b-/- ) mice but are almost normal in Stx1a null mutant (Stx1a-/- ) mice. These observations suggested that STX1A and STX1B have distinct functions in fast synaptic transmission in the central nervous system (CNS). Interestingly, recent studies indicated that Stx1a-/- or Stx1a+/- mice exhibit disruption in the monoaminergic system in the CNS, causing unusual behaviour that is similar to neuropsychological alterations observed in psychiatric patients. Here, we studied whether STX1B contributes to the regulation of monoaminergic system and if STX1B is related to neuropsychological properties in human neuropsychological disorders similar to STX1A. We found that monoamine release in vitro was normal in Stx1b+/- mice unlike Stx1a-/- or Stx1a+/- mice, but the basal extracellular dopamine (DA) concentration in the ventral striatum was increased. DA secretion in the ventral striatum is regulated by GABAergic neurons, and Stx1b+/- mice exhibited reduced GABA release both in vitro and in vivo, disrupting the DAergic system in the CNS of these mice. We also found that Stx1b+/- mice exhibited reduced pre-pulse inhibition (PPI), which is believed to represent one of the prominent schizotypal behavioural profiles of human psychiatric patients. The reduction in PPI was rescued by DA receptor antagonists. These observations indicated that STX1B contributes to excess activity of the DAergic system through regulation of GABAergic transmission.
Collapse
Affiliation(s)
- Tomonori Fujiwara
- Department of Cell Physiology, Kyorin University School of Medicine, Shinkawa, Mitaka, Tokyo, 181-8611, Japan
| | - Takefumi Kofuji
- Department of Cell Physiology, Kyorin University School of Medicine, Shinkawa, Mitaka, Tokyo, 181-8611, Japan.,Radioisotope Laboratory, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Tatsuya Mishima
- Department of Cell Physiology, Kyorin University School of Medicine, Shinkawa, Mitaka, Tokyo, 181-8611, Japan
| | - Kimio Akagawa
- Department of Cell Physiology, Kyorin University School of Medicine, Shinkawa, Mitaka, Tokyo, 181-8611, Japan
| |
Collapse
|
15
|
Cannabidiol Counteracts Amphetamine-Induced Neuronal and Behavioral Sensitization of the Mesolimbic Dopamine Pathway through a Novel mTOR/p70S6 Kinase Signaling Pathway. J Neurosci 2017; 36:5160-9. [PMID: 27147666 DOI: 10.1523/jneurosci.3387-15.2016] [Citation(s) in RCA: 95] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 02/25/2016] [Indexed: 12/13/2022] Open
Abstract
UNLABELLED Schizophrenia-related psychosis is associated with disturbances in mesolimbic dopamine (DA) transmission, characterized by hyperdopaminergic activity in the mesolimbic pathway. Currently, the only clinically effective treatment for schizophrenia involves the use of antipsychotic medications that block DA receptor transmission. However, these medications produce serious side effects leading to poor compliance and treatment outcomes. Emerging evidence points to the involvement of a specific phytochemical component of marijuana called cannabidiol (CBD), which possesses promising therapeutic properties for the treatment of schizophrenia-related psychoses. However, the neuronal and molecular mechanisms through which CBD may exert these effects are entirely unknown. We used amphetamine (AMPH)-induced sensitization and sensorimotor gating in rats, two preclinical procedures relevant to schizophrenia-related psychopathology, combined with in vivo single-unit neuronal electrophysiology recordings in the ventral tegmental area, and molecular analyses to characterize the actions of CBD directly in the nucleus accumbens shell (NASh), a brain region that is the current target of most effective antipsychotics. We demonstrate that Intra-NASh CBD attenuates AMPH-induced sensitization, both in terms of DAergic neuronal activity measured in the ventral tegmental area and psychotomimetic behavioral analyses. We further report that CBD controls downstream phosphorylation of the mTOR/p70S6 kinase signaling pathways directly within the NASh. Our findings demonstrate a novel mechanism for the putative antipsychotic-like properties of CBD in the mesolimbic circuitry. We identify the molecular signaling pathways through which CBD may functionally reduce schizophrenia-like neuropsychopathology. SIGNIFICANCE STATEMENT The cannabis-derived phytochemical, cannabidiol (CBD), has been shown to have pharmacotherapeutic efficacy for the treatment of schizophrenia. However, the mechanisms by which CBD may produce antipsychotic effects are entirely unknown. Using preclinical behavioral procedures combined with molecular analyses and in vivo neuronal electrophysiology, our findings identify a functional role for the nucleus accumbens as a critical brain region whereby CBD can produce effects similar to antipsychotic medications by triggering molecular signaling pathways associated with the effects of classic antipsychotic medications. Specifically, we report that CBD can attenuate both behavioral and dopaminergic neuronal correlates of mesolimbic dopaminergic sensitization, via a direct interaction with mTOR/p70S6 kinase signaling within the mesolimbic pathway.
Collapse
|
16
|
Simmons DV, Petko AK, Paladini CA. Differential expression of long-term potentiation among identified inhibitory inputs to dopamine neurons. J Neurophysiol 2017; 118:1998-2008. [PMID: 28701538 DOI: 10.1152/jn.00270.2017] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 07/06/2017] [Accepted: 07/10/2017] [Indexed: 01/10/2023] Open
Abstract
The in vivo firing pattern of ventral tegmental area (VTA) dopamine neurons is controlled by GABA afferents originating primarily from the nucleus accumbens (NAc), rostromedial tegmental nucleus (RMTg), and local GABA neurons within the VTA. Although different forms of plasticity have been observed from GABA inputs to VTA dopamine neurons, one dependent on cyclic GMP synthesis and the other on adenylyl cyclase activation, it is unknown whether plasticity is differentially expressed in each. Using an optogenetic strategy, we show that identified inhibitory postsynaptic currents (IPSCs) from local VTA GABA neurons and NAc afferents exhibit a cyclic GMP-dependent long-term potentiation (LTP) that is capable of inhibiting the firing activity of dopamine neurons. However, this form of LTP was not induced from RMTg afferents. Only an adenylyl cyclase-mediated increase in IPSCs was exhibited by all three inputs. Thus discrete plasticity mechanisms recruit overlapping but different subsets of GABA inputs to VTA dopamine neurons.NEW & NOTEWORTHY We describe a mapping of plasticity expression, mediated by different mechanisms, among three distinct GABA afferents to ventral tegmental area (VTA) dopamine neurons: the rostromedial tegmental nucleus, the nucleus accumbens, and the local GABA neurons within the VTA known to synapse on VTA dopamine neurons. This work is the first demonstration that discrete plasticity mechanisms recruit overlapping but different subsets of GABA inputs to VTA dopamine neurons.
Collapse
Affiliation(s)
- DeNard V Simmons
- Neurosciences Institute, The University of Texas at San Antonio, San Antonio, Texas
| | - Alyssa K Petko
- Neurosciences Institute, The University of Texas at San Antonio, San Antonio, Texas
| | - Carlos A Paladini
- Neurosciences Institute, The University of Texas at San Antonio, San Antonio, Texas
| |
Collapse
|
17
|
Karim TJ, Reyes-Vazquez C, Dafny N. Comparison of the VTA and LC response to methylphenidate: a concomitant behavioral and neuronal study of adolescent male rats. J Neurophysiol 2017; 118:1501-1514. [PMID: 28615331 DOI: 10.1152/jn.00145.2017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 06/12/2017] [Accepted: 06/12/2017] [Indexed: 12/21/2022] Open
Abstract
Methylphenidate (MPD), also known as Ritalin, is a psychostimulant used to treat attention deficit hyperactivity disorder. However, it is increasingly being misused by normal adolescents for recreation and academic advantage. Therefore, it is important to elucidate the behavioral and neurophysiological effects of MPD in normal subjects. MPD inhibits the reuptake of catecholamines, mainly found in the ventral tegmental area (VTA) and locus coeruleus (LC). The VTA and LC normally mediate attention, motivation, and drug reward behaviors. Selective neuronal connections between the VTA and LC have been identified implicating regular interaction between the structures. The objective of this study was to compare the neuronal responses of the VTA and LC to MPD in normal adolescent rats. Animals were implanted with permanent electrodes in the VTA and LC, and neuronal units were recorded following acute and repetitive (chronic) saline or 0.6, 2.5, or 10.0 mg/kg MPD exposure. Animals displayed either behavioral sensitization or tolerance to all three doses of MPD. Acute MPD exposure elicited excitation in the majority of all VTA and LC units. Chronic MPD exposure elicited a further increase in VTA and LC neuronal activity in animals exhibiting behavioral sensitization and an attenuation in VTA and LC neuronal activity in animals exhibiting behavioral tolerance, demonstrating neurophysiological sensitization and tolerance, respectively. The similar pattern in VTA and LC unit activity suggests that the two structures are linked in their response to MPD. These results may help determine the exact mechanism of action of MPD, resulting in optimized treatment of patients.NEW & NOTEWORTHY The same dose of 0.6, 2.5, and 10 mg/kg methylphenidate (MPD) elicits either behavioral sensitization or tolerance in adolescent rats. There is a direct correlation between the ventral tegmental area (VTA) and locus coeruleus (LC) neuronal response to chronic MPD exposure. Both the VTA and LC are involved in the behavioral and neurophysiological effects of chronic MPD.
Collapse
Affiliation(s)
- Tahseen J Karim
- Department of Neurobiology and Anatomy, McGovern Medical School, Houston, Texas
| | - Cruz Reyes-Vazquez
- Department of Neurobiology and Anatomy, McGovern Medical School, Houston, Texas
| | - Nachum Dafny
- Department of Neurobiology and Anatomy, McGovern Medical School, Houston, Texas
| |
Collapse
|
18
|
Sil’kis IG, Markevich VA. The influence of acetylcholine, dopamine, and GABA on the functioning of the corticostriatal neuronal network in Alzheimer’s and Parkinson’s diseases: A hypothetical mechanism. NEUROCHEM J+ 2017. [DOI: 10.1134/s1819712416040103] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
19
|
Faison SL, Schindler CW, Goldberg SR, Wang JB. l-tetrahydropalmatine reduces nicotine self-administration and reinstatement in rats. BMC Pharmacol Toxicol 2016; 17:49. [PMID: 27817750 PMCID: PMC5098281 DOI: 10.1186/s40360-016-0093-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 10/04/2016] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND The negative consequences of nicotine use are well known and documented, however, abstaining from nicotine use and achieving abstinence poses a major challenge for the majority of nicotine users trying to quit. l-Tetrahydropalmatine (l-THP), a compound extracted from the Chinese herb Corydalis, displayed utility in the treatment of cocaine and heroin addiction via reduction of drug-intake and relapse. The present study examined the effects of l-THP on abuse-related effects of nicotine. METHODS Self-administration and reinstatement testing was conducted. Rats trained to self-administer nicotine (0.03 mg/kg/injection) under a fixed-ratio 5 schedule (FR5) of reinforcement were pretreated with l-THP (3 or 5 mg/kg), varenicline (1 mg/kg), bupropion (40 mg/kg), or saline before daily 2-h sessions. Locomotor, food, and microdialysis assays were also conducted in separate rats. RESULTS l-THP significantly reduced nicotine self-administration (SA). l-THP's effect was more pronounced than the effect of varenicline and similar to the effect of bupropion. In reinstatement testing, animals were pretreated with the same compounds, challenged with nicotine (0.3 mg/kg, s.c.), and reintroduced to pre-extinction conditions. l-THP blocked reinstatement of nicotine seeking more effectively than either varenicline or bupropion. Locomotor data revealed that therapeutic doses of l-THP had no inhibitory effects on ambulatory ability and that l-THP (3 and 5 mg/kg) significantly blocked nicotine induced hyperactivity when administered before nicotine. In in-vivo microdialysis experiments, l-THP, varenicline, and bupropion alone elevated extracellular dopamine (DA) levels in the nucleus accumbens shell (nAcb). CONCLUSIONS Since l-THP reduces nicotine taking and blocks relapse it could be a useful alternative to varenicline and bupropion as a treatment for nicotine addiction.
Collapse
Affiliation(s)
- Shamia L. Faison
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, MD USA
- Preclinical Pharmacology Section, Behavioral Neuroscience Research Branch, National Institute on Drug Abuse, National Institutes of Health, DHHS, Baltimore, MD USA
| | - Charles W. Schindler
- Preclinical Pharmacology Section, Behavioral Neuroscience Research Branch, National Institute on Drug Abuse, National Institutes of Health, DHHS, Baltimore, MD USA
| | - Steven R. Goldberg
- Preclinical Pharmacology Section, Behavioral Neuroscience Research Branch, National Institute on Drug Abuse, National Institutes of Health, DHHS, Baltimore, MD USA
| | - Jia Bei Wang
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, MD USA
| |
Collapse
|
20
|
Midbrain functional connectivity and ventral striatal dopamine D2-type receptors: link to impulsivity in methamphetamine users. Mol Psychiatry 2016; 21:1554-1560. [PMID: 26830141 PMCID: PMC4970974 DOI: 10.1038/mp.2015.223] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Revised: 11/11/2015] [Accepted: 12/07/2015] [Indexed: 12/23/2022]
Abstract
Stimulant use disorders are associated with deficits in striatal dopamine receptor availability, abnormalities in mesocorticolimbic resting-state functional connectivity (RSFC) and impulsivity. In methamphetamine-dependent research participants, impulsivity is correlated negatively with striatal D2-type receptor availability, and mesocorticolimbic RSFC is stronger than that in controls. The extent to which these features of methamphetamine dependence are interrelated, however, is unknown. This question was addressed in two studies. In Study 1, 19 methamphetamine-dependent and 26 healthy control subjects underwent [18F]fallypride positron emission tomography to measure ventral striatal dopamine D2-type receptor availability, indexed by binding potential (BPND), and functional magnetic resonance imaging (fMRI) to assess mesocorticolimbic RSFC, using a midbrain seed. In Study 2, an independent sample of 20 methamphetamine-dependent and 18 control subjects completed the Barratt Impulsiveness Scale in addition to fMRI. Study 1 showed a significant group by ventral striatal BPND interaction effect on RSFC, reflecting a negative relationship between ventral striatal BPND and RSFC between the midbrain and striatum, orbitofrontal cortex and insula in methamphetamine-dependent participants, but a positive relationship in the control group. In Study 2, an interaction of the group with RSFC on impulsivity was observed. Methamphetamine-dependent users exhibited a positive relationship of midbrain RSFC to the left ventral striatum with cognitive impulsivity, whereas a negative relationship was observed in healthy controls. The results indicate that ventral striatal D2-type receptor signaling may affect the system-level activity within the mesocorticolimbic system, providing a functional link that may help explain high impulsivity in methamphetamine-dependent individuals.
Collapse
|
21
|
Oliva I, Wanat MJ. Ventral Tegmental Area Afferents and Drug-Dependent Behaviors. Front Psychiatry 2016; 7:30. [PMID: 27014097 PMCID: PMC4780106 DOI: 10.3389/fpsyt.2016.00030] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 02/23/2016] [Indexed: 01/10/2023] Open
Abstract
Drug-related behaviors in both humans and rodents are commonly thought to arise from aberrant learning processes. Preclinical studies demonstrate that the acquisition and expression of many drug-dependent behaviors involves the ventral tegmental area (VTA), a midbrain structure comprised of dopamine, GABA, and glutamate neurons. Drug experience alters the excitatory and inhibitory synaptic input onto VTA dopamine neurons, suggesting a critical role for VTA afferents in mediating the effects of drugs. In this review, we present evidence implicating the VTA in drug-related behaviors, highlight the diversity of neuronal populations in the VTA, and discuss the behavioral effects of selectively manipulating VTA afferents. Future experiments are needed to determine which VTA afferents and what neuronal populations in the VTA mediate specific drug-dependent behaviors. Further studies are also necessary for identifying the afferent-specific synaptic alterations onto dopamine and non-dopamine neurons in the VTA following drug administration. The identification of neural circuits and adaptations involved with drug-dependent behaviors can highlight potential neural targets for pharmacological and deep brain stimulation interventions to treat substance abuse disorders.
Collapse
Affiliation(s)
- Idaira Oliva
- Department of Biology, Neurosciences Institute, University of Texas at San Antonio , San Antonio, TX , USA
| | - Matthew J Wanat
- Department of Biology, Neurosciences Institute, University of Texas at San Antonio , San Antonio, TX , USA
| |
Collapse
|
22
|
Hernandez G, Cheer JF. To Act or Not to Act: Endocannabinoid/Dopamine Interactions in Decision-Making. Front Behav Neurosci 2015; 9:336. [PMID: 26733830 PMCID: PMC4681836 DOI: 10.3389/fnbeh.2015.00336] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Accepted: 11/19/2015] [Indexed: 12/11/2022] Open
Abstract
Decision-making is an ethologically adaptive construct that is impaired in multiple psychiatric disorders. Activity within the mesocorticolimbic dopamine system has been traditionally associated with decision-making. The endocannabinoid system through its actions on inhibitory and excitatory synapses modulates dopamine activity and decision-making. The aim of this brief review is to present a synopsis of available data obtained when the endocannabinoid system is manipulated and dopamine activity recorded. To this end, we review research using different behavioral paradigms to provide further insight into how this ubiquitous signaling system biases dopamine-related behaviors to regulate decision-making.
Collapse
Affiliation(s)
- Giovanni Hernandez
- Faculté de Pharmacie, Université de Montréal Montréal, Quebec, QC, Canada
| | - Joseph F Cheer
- Department of Anatomy and Neurobiology, University of Maryland School of MedicineBaltimore, Maryland, MD, USA; Department of Psychiatry, University of Maryland School of MedicineBaltimore, Maryland, MD, USA
| |
Collapse
|
23
|
Adermark L, Morud J, Lotfi A, Jonsson S, Söderpalm B, Ericson M. Age-contingent influence over accumbal neurotransmission and the locomotor stimulatory response to acute and repeated administration of nicotine in Wistar rats. Neuropharmacology 2015; 97:104-12. [PMID: 26079444 DOI: 10.1016/j.neuropharm.2015.06.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Revised: 05/28/2015] [Accepted: 06/01/2015] [Indexed: 10/23/2022]
Abstract
Nicotine addiction is one of the leading contributors to the global burden of disease, and early onset smokers report a more severe addiction with lower chance of cessation than those with a late onset. Preclinical research supports an age-dependent component to the rewarding and reinforcing properties of nicotine, and the aim of this study was to define behavioral adaptations and changes in accumbal neurotransmission that arise over 15 days of intermittent nicotine treatment (0.36 mg/kg/day) in rats of three different ages (5 weeks, 10 weeks, 36 weeks old). Repeated treatment increased the locomotor stimulatory response to nicotine in all age groups, but significantly faster in the two younger groups. In addition, nicotine decreased rearing activity in a way that sustained even after repeated administration in aged rats but not in the younger age groups. Electrophysiological field potential recordings revealed a decline in input/output function in the nucleus accumbens (NAc) of animals intermittently treated with nicotine starting at 5 weeks of age, but not in older animals. In drug naïve rats, acute administration of nicotine modulated both accumbal dopamine output and excitatory transmission in a partially age-dependent manner. Fifteen days of intermittent nicotine treatment did not alter the acute effect displayed by nicotine on dopamine levels or evoked field potentials. The data presented here show that both acute and repeated nicotine administration modulates accumbal neurotransmission and behavior in an age-contingent manner and that these age-dependent differences could reflect important neurobiological underpinnings associated with the increased vulnerability for nicotine-addiction in adolescents.
Collapse
Affiliation(s)
- L Adermark
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.
| | - J Morud
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - A Lotfi
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - S Jonsson
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - B Söderpalm
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden; Beroendekliniken, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - M Ericson
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| |
Collapse
|
24
|
Galaj E, Manuszak M, Arastehmanesh D, Ranaldi R. Microinjections of a dopamine D1 receptor antagonist into the ventral tegmental area block the expression of cocaine conditioned place preference in rats. Behav Brain Res 2014; 272:279-85. [PMID: 25017572 DOI: 10.1016/j.bbr.2014.07.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Revised: 06/11/2014] [Accepted: 07/03/2014] [Indexed: 11/17/2022]
Abstract
Stimulation of dopamine (DA) D1 receptors in the ventral tegmental area (VTA) is involved in primary rewards. In the current study we investigated whether VTA D1 receptor stimulation likewise plays a role in mediating the rewarding effects of cocaine-associated stimuli, using the cocaine conditioned place preference (CPP) paradigm. Rats were prepared with cannulae so as to allow microinjections in the VTA and later conditioned to a cocaine-associated environment using the CPP paradigm. Prior to each conditioning session rats were injected with either saline or cocaine (10mg/kg, intraperitoneally) and then placed in one of the two sides of the CPP apparatus. Sessions lasted 30min a day over a period of eight days, such that rats alternated daily between consistently experiencing cocaine in one side and saline in the other. On the test day, which was conducted one day after conditioning, rats were given bilateral microinjections of one of four doses of the D1 antagonist, SCH 23390, (0, 2, 4 or 8μg/0.5μl) directly into the VTA and allowed free access to both sides of the apparatus. Preference for either side was measured as time spent in each side and compared to the same measures taken before conditioning. The D1 antagonist produced a dose-related, significant reduction in the preference for the cocaine-paired side compared to vehicle. These data suggest that the expression of cocaine conditioned place preference requires stimulation of VTA D1 receptors and, as such, are the first to suggest a role for VTA dendritically released DA in cocaine-, or other reward-, related learning.
Collapse
Affiliation(s)
- E Galaj
- Graduate Center of City University of New York, NY, United States
| | | | | | - R Ranaldi
- Graduate Center of City University of New York, NY, United States; Queens College, NY, United States.
| |
Collapse
|
25
|
Effects of alcohol on the membrane excitability and synaptic transmission of medium spiny neurons in the nucleus accumbens. Alcohol 2012; 46:317-27. [PMID: 22445807 DOI: 10.1016/j.alcohol.2011.12.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Revised: 12/05/2011] [Accepted: 12/19/2011] [Indexed: 12/29/2022]
Abstract
Chronic and excessive alcohol drinking lead to alcohol dependence and loss of control over alcohol consumption, with serious detrimental health consequences. Chronic alcohol exposure followed by protracted withdrawal causes profound alterations in the brain reward system that leads to marked changes in reinforcement mechanisms and motivational state. These long-lasting neuroadaptations are thought to contribute to the development of cravings and relapse. The nucleus accumbens (NAcc), a central component of the brain reward system, plays a critical role in alcohol-induced neuroadaptive changes underlying alcohol-seeking behaviors. Here we review the findings that chronic alcohol exposure produces long-lasting neuroadaptive changes in various ion channels that govern intrinsic membrane properties and neuronal excitability, as well as excitatory and inhibitory synaptic transmission in the NAcc that underlie alcohol-seeking behavior during protracted withdrawal.
Collapse
|
26
|
Nucleus accumbens medium spiny neurons target non-dopaminergic neurons in the ventral tegmental area. J Neurosci 2011; 31:7811-6. [PMID: 21613494 DOI: 10.1523/jneurosci.1504-11.2011] [Citation(s) in RCA: 159] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The midbrain ventral tegmental area (VTA) projection to the nucleus accumbens (NAc) is implicated in motivation and reinforcement. A significant number of NAc medium spiny neurons (MSNs) project back to the VTA, although the nature of this projection is essentially unknown. For example, do NAc MSNs directly target accumbens-projecting dopamine neurons and do they act via the GABA(A) or GABA(B) receptor? To address these issues, we expressed the light-sensitive channel rhodopsin-2 in the rat NAc and made electrophysiological recordings from VTA neurons ex vivo. We found that the NAc directly targets non-dopaminergic VTA neurons, including some that project back to the NAc. These MSN GABAergic terminals are opioid sensitive and act via GABA(A) receptors.
Collapse
|
27
|
Danielli B, Scheggi S, Grappi S, Marchese G, De Montis MG, Tagliamonte A, Gambarana C. Modifications in DARPP-32 phosphorylation pattern after repeated palatable food consumption undergo rapid habituation in the nucleus accumbens shell of non-food-deprived rats. J Neurochem 2010; 112:531-41. [DOI: 10.1111/j.1471-4159.2009.06483.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
28
|
Sotty F, Montezinho LP, Steiniger-Brach B, Nielsen J. Phosphodiesterase 10A inhibition modulates the sensitivity of the mesolimbic dopaminergic system to D-amphetamine: involvement of the D1-regulated feedback control of midbrain dopamine neurons. J Neurochem 2009; 109:766-75. [PMID: 19236563 DOI: 10.1111/j.1471-4159.2009.06004.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Phosphodiesterase (PDE) 10A is highly expressed in medium spiny neurons of the striatum, at the confluence of the corticostriatal glutamatergic and the midbrain dopaminergic pathways, both believed to be involved in the physiopathology of schizophrenia. There is a growing body of evidence suggesting that targeting PDE10A may be beneficial for the treatment of positive symptoms in schizophrenia. The aim of the present study was to investigate how PDE10A inhibition modulates mesolimbic dopaminergic neurotransmission. We found that the selective PDE10A inhibitor, MP-10, blocked D-amphetamine-induced hyperactivity as well as D-amphetamine-induced dopamine efflux in the nucleus accumbens in a dose-dependent manner. We further investigated the mechanism by which PDE10A inhibition affects dopaminergic neurotransmission. We report that MP-10 potentiated the effect of a high but not a low dose of D-amphetamine on the mean firing rate of dopaminergic neurons recorded from the ventral tegmental area. Similarly, the effect of a high, but not a low dose of D-amphetamine, was completely reversed by the selective D(1) antagonist, SCH23390. These data suggest that the D(1)-regulated feedback control of midbrain dopamine neurons is a critical pathway involved in the modulation of the response of mesolimbic dopamine neurons to D-amphetamine by PDE10A inhibition.
Collapse
Affiliation(s)
- Florence Sotty
- Department of Neurophysiology, H. Lundbeck A/S, Copenhagen-Valby, Denmark.
| | | | | | | |
Collapse
|
29
|
Sagara H, Kitamura Y, Sendo T, Araki H, Gomita Y. Motivational effect of nomifensine in the intracranial self-stimulation behavior using a runway method. Biol Pharm Bull 2008; 31:1036-40. [PMID: 18451543 DOI: 10.1248/bpb.31.1036] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Intracranial self-stimulation (ICSS) behavior is an experimental methodology to study reward and motivational effects. We have established a new paradigm to evaluate enhancing motivation by drugs in the runway method using the priming stimulation of ICSS. In the present study, we investigated the effects of nomifensine on the experimental extinction process of non-reinforcing reward and pre-trial electric priming stimulations in lateral hypothalamic self-stimulation. In this study, the experimental extinction process of the non-reinforcing reward means the experimental method of excluding reward effect in ICSS behavior. The extinction process in the runway method consisted of these 15 trials. Nomifensine, an antidepressant drug, delayed the running speed of the extinction process at doses of 5 and 10 mg/kg (i.p.) compared with the vehicle alone. This result suggests that the delay in the running speed of the extinction process promotes a motivational effect in rats. Previously, priming stimulation in the runway method was found to affect motivational function of ICSS. Therefore, our findings suggest the possible application of nomifensine for improving motivation.
Collapse
Affiliation(s)
- Hidenori Sagara
- Department of Hospital Pharmacy, Okayama University Medical School, 2-5-1 Shikata-cho, Okayama 700-8558, Japan
| | | | | | | | | |
Collapse
|
30
|
Eiler WJA, June HL. Blockade of GABA(A) receptors within the extended amygdala attenuates D(2) regulation of alcohol-motivated behaviors in the ventral tegmental area of alcohol-preferring (P) rats. Neuropharmacology 2007; 52:1570-9. [PMID: 17451754 PMCID: PMC2743737 DOI: 10.1016/j.neuropharm.2007.03.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2006] [Revised: 02/27/2007] [Accepted: 03/01/2007] [Indexed: 11/19/2022]
Abstract
The dopamine (DA) mesolimbic pathway, which originates from DA cell bodies within the ventral tegmental area (VTA), has been shown by various studies to play a role in the mediation of various drugs of abuse including alcohol (EtOH). It has been suggested that the VTA's control of EtOH reward is mediated in part by the D2 receptors within the VTA. These receptors may be under the regulation of reciprocal GABAergic inputs from forebrain components of the mesolimbic path such as the nucleus accumbens (NAcc), a classic EtOH reward substrate, and the bed nucleus of the stria terminalis, a substrate recently implicated in EtOH reinforcement, forming a self-regulating feedback loop. To test this hypothesis, D2 regulation of EtOH self-administration (SA) was evaluated by the microinfusion of the D2 antagonist eticlopride into the VTA of P rats, which produced profound reductions in EtOH SA in the highest (20.0 and 40.0microg) doses tested in both BST/VTA and NAcc/VTA implanted P rats. To determine the role of GABA in the mediation of EtOH SA, a 32.0ng dose the non-selective GABA antagonist SR 95531 was microinfused into the BST producing no effect on responding for EtOH and into the NAcc which lead to a reduction in EtOH responding. Finally, the hypothesis that GABA innervation of the VTA from the mesolimbic forebrain may influence EtOH SA was examined by the simultaneous infusion of eticlopride (40.0microg) into the VTA and SR 95531 (32.0ng) into either the BST or NAcc. This combination infusion completely attenuated the reduction in EtOH SA observed with the 40.0microg dose of eticlopride alone in both groups of animals. These results suggest that while the D2 receptors within the VTA regulate EtOH-motivated behaviors, this is modulated by GABAergic input from the mesolimbic forebrain, specifically from the BST and NAcc.
Collapse
Affiliation(s)
- William JA Eiler
- Psychobiology of Addictions Program, Department of Psychology, Indiana University-Purdue University, Indianapolis, IN 46202
| | - Harry L. June
- Division of Alcohol and Drug Abuse, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD 21201
- Department of Pharmacology and Experimental Therapeutics, University of Maryland School of Medicine, Baltimore, MD 21201
| |
Collapse
|
31
|
David HN, Ansseau M, Abraini JH. Dopamine-glutamate reciprocal modulation of release and motor responses in the rat caudate-putamen and nucleus accumbens of "intact" animals. ACTA ACUST UNITED AC 2005; 50:336-60. [PMID: 16278019 DOI: 10.1016/j.brainresrev.2005.09.002] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2004] [Revised: 09/10/2005] [Accepted: 09/16/2005] [Indexed: 10/25/2022]
Abstract
Functional interactions between dopaminergic neurotransmission and glutamatergic neurotransmission are well known to play a crucial integrative role in the striatum, the major input structure of the basal ganglia now widely recognized to contribute to the control of motor activity and movements but also to the processing of cognitive and limbic functions. However, the nature of these interactions is still a matter of debate and controversy. This review (1) summarizes anatomical data on the distribution of dopaminergic and glutamatergic receptors in the striatum-accumbens complex, (2) focuses on the dopamine-glutamate interactions in the modulation of each other's release in the striatum-accumbens complex, and (3) examines the dopamine-glutamate interactions in the entire striatum involved in the control of locomotor activity. The effects of dopaminergic and glutamatergic receptor selective agonists and antagonists on dopamine and glutamate release as well on motor responses are analyzed in the entire striatum, by reviewing both in vitro and in vivo data. Regarding in vivo data, only findings from focal injections studies in the nucleus accumbens or the caudate-putamen of "intact" animals are reviewed. Altogether, the available data demonstrate that dopamine and glutamate do not uniformly interact to modulate each others' release and postsynaptic modulation of striatal output neurons. Depending on the receptor subtypes involved, interactions between dopaminergic and glutamatergic transmission vary as a multiple and complex combination of tonic, phasic, facilitatory, and inhibitory properties.
Collapse
Affiliation(s)
- Hélène N David
- Unité de Psychologie Médicale, CHU Sart-Tilman, B 4000 Liège, Belgium.
| | | | | |
Collapse
|
32
|
Broom SL, Yamamoto BK. Effects of subchronic methamphetamine exposure on basal dopamine and stress-induced dopamine release in the nucleus accumbens shell of rats. Psychopharmacology (Berl) 2005; 181:467-76. [PMID: 15986185 DOI: 10.1007/s00213-005-0007-6] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2004] [Accepted: 03/15/2005] [Indexed: 10/25/2022]
Abstract
RATIONALE Subchronic administration of stimulants reduces basal dopamine (DA) concentrations and blocks stress-induced DA release in the nucleus accumbens (NA) of rats during withdrawal. However, no studies have attempted to relate early withdrawal from chronic drug exposure to stress reactivity and changes in DA transmission. OBJECTIVES The effects of subchronic low-dose methamphetamine (METH) administration on regional changes in dopamine transporter (DAT) and norepinephrine transporter (NET) immunoreactivity and function during early withdrawal were examined. The effects of subchronic METH on stress responsivity measured by DA release in the nucleus accumbens shell (NA SHELL) and core (NA CORE) during acute restraint stress were also examined. METHODS Male rats received single injections of METH (2.0 mg/kg i.p.) or saline (SAL) for 10 days and then were killed 24 h after the last injection. DAT and NET protein in NA, striatum (STR), medial prefrontal cortex (mPFC), and hippocampus were assayed by Western blot analysis. Experiment 2 measured basal extracellular DA concentrations and restraint-stress-induced DA release in vivo in the NA SHELL and CORE of SAL- and METH-pretreated rats after 24-h withdrawal. Experiment 3 examined the in vivo regulation of extracellular DA in the NA SHELL and/or CORE after local administration of GBR12909 (50 microM) or nisoxetine (100 microM; NA SHELL). RESULTS Subchronic METH increased DAT but not NET immunoreactivity in the NA compared to the STR and mPFC. METH reduced basal extracellular DA and blocked restraint-stress-induced DA release in the NA SHELL. DA uptake blockade increased extracellular DA more in the NA SHELL of METH rats, whereas NE uptake blockade increased basal DA concentrations to a similar extent in METH and SAL rats. CONCLUSIONS These results suggest that subchronic METH exposure selectively increases NA DAT and consequently reduces basal and stress-induced DA release in the NA SHELL during early withdrawal.
Collapse
Affiliation(s)
- Susan L Broom
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Room L-613, 715 Albany Street, Boston, MA 02118, USA
| | | |
Collapse
|
33
|
Rahman S, Zhang J, Corrigall WA. Effects of nicotine preexposure on sulpiride-induced dopamine release in the nucleus accumbens. Eur J Pharmacol 2005; 494:31-4. [PMID: 15194448 DOI: 10.1016/j.ejphar.2004.04.044] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2003] [Revised: 03/08/2004] [Accepted: 04/26/2004] [Indexed: 11/20/2022]
Abstract
We examined the effects of nicotine preexposure or saline on dopamine release to sulpiride in the rat nucleus accumbens. Microdialysis was used to locally perfuse the sulpiride into the ventral tegmental area while sampling dopamine levels in the nucleus accumbens. The increase (130% and 165% of basal) in extracellular accumbens dopamine levels observed during ventral tegmental area perfusion for 80 min with 10-100 microM sulpiride in saline-treated animals was reduced (128% and 105% of basal) in nicotine-preexposed animals. The reduction of sulpiride-induced nucleus accumbens dopamine release after nicotine treatment is likely the result of down-regulation of somatodendritic dopamine autoreceptors.
Collapse
Affiliation(s)
- Shafiqur Rahman
- Smoking and Nicotine Dependence Research, Centre for Addiction and Mental Health, and Department of Psychiatry, University of Toronto, Toronto, ON, Canada.
| | | | | |
Collapse
|
34
|
Andrews CM, Kung HF, Lucki I. The 5-HT1A receptor modulates the effects of cocaine on extracellular serotonin and dopamine levels in the nucleus accumbens. Eur J Pharmacol 2005; 508:123-30. [PMID: 15680262 DOI: 10.1016/j.ejphar.2004.12.033] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2004] [Accepted: 12/07/2004] [Indexed: 11/20/2022]
Abstract
The regulation of extracellular levels of serotonin (5-HT) and dopamine in response to cocaine by 5-HT1A receptors was examined using in vivo microdialysis and the 5-HT1A receptor antagonist 4-(2'-methoxy-)-phenyl-1-[2'-(N-2''-pyridinyl)-p-fluorobenzamido-]ethyl-piperazine (p-MPPF). Pretreatment with p-MPPF significantly augmented the increase in extracellular levels of both 5-HT and dopamine in the nucleus accumbens produced by systemic administration of cocaine. Levels of 5-HT or dopamine were unaffected by p-MPPF given alone. Extracellular levels of 5-HT and dopamine were increased dramatically by cocaine infused locally into the nucleus accumbens. Systemic injection of cocaine given during the cocaine infusion reduced 5-HT and dopamine levels, presumably by activating inhibitory 5-HT and dopamine autoreceptors outside of the locus of infusion. The reduction of 5-HT and dopamine levels by systemic cocaine during accumbal infusion was blocked by pretreatment with the 5-HT1A receptor antagonist p-MPPF. Taken together, these findings suggest that the 5-HT1A autoreceptor acts to modulate the effects of cocaine on both 5-HT and dopamine levels in the nucleus accumbens.
Collapse
Affiliation(s)
- Christine M Andrews
- Institute of Neurological Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA
| | | | | |
Collapse
|
35
|
Rahman S, Zhang J, Corrigall WA. Local perfusion of nicotine differentially modulates somatodendritic dopamine release in the rat ventral tegmental area after nicotine preexposure. Neurochem Res 2004; 29:1687-93. [PMID: 15453263 DOI: 10.1023/b:nere.0000035803.64724.17] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
We examined the effects of nicotine perfusion into the ventral tegmental area (VTA) on extracellular dopamine (DA) levels in rats using in vivo microdialysis. Local perfusion with nicotine for 80 min (10-100 microM) modestly increased (approximately 105-131% of basal) the extracellular DA levels in the VTA of rats that had been pretreated with saline for 5 days. In animals that had been pretreated with nicotine for 5 days (0.3 mg/kg, s.c.), perfusion with nicotine for 80 min (10-100 microM) dose-dependently increased the extracellular DA levels in the VTA of rats and did so to a greater extent than in saline-pretreated animals (125-171% of basal). Co-perfusion through the dialysis probe with 100 microM mecamylamine, a nonselective nicotinic acetylcholine receptor (nAChR) antagonist, or 100 microM dihydro-beta-erythroidine, a high affinity and competitive nAChR antagonist, attenuated the enhancement of extracellular DA levels produced by 100 microM nicotine alone. These results suggest that local nicotine challenge potentiated the somatodendritic DA release after nicotine preexposure by stimulation of high-affinity nAChRs in the VTA.
Collapse
Affiliation(s)
- S Rahman
- Smoking and Nicotine Dependence Research, Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario M5S 2S1, Canada.
| | | | | |
Collapse
|
36
|
Fuchs H, Hauber W. Changes in extracellular dopamine in the rat globus pallidus induced by typical and atypical antipsychotic drugs. Neurochem Int 2004; 45:1029-38. [PMID: 15337302 DOI: 10.1016/j.neuint.2004.05.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2004] [Revised: 04/30/2004] [Accepted: 05/14/2004] [Indexed: 01/23/2023]
Abstract
Typical antipsychotic drugs with a high extrapyramidal motor side-effects liability markedly increase extracellular dopamine in the caudate-putamen, while atypical antipsychotic drugs with a low incidence of extrapyramidal motor side-effects have less pronounced stimulating actions on striatal dopamine. Therefore, it has been suggested that the extrapyramidal motor side-effects liability of antipsychotic drugs (APD) is correlated with their ability to increase extracellular dopamine in the caudate-putamen. The globus pallidus (GP) is another basal ganglia structure probably mediating extrapyramidal motor side-effects of typical antipsychotic drugs. Therefore, the present study sought to determine whether extracellular dopamine in the globus pallidus might be a further indicator to differentiate neurochemical actions of typical and atypical antipsychotic drugs. Using in vivo microdialysis we compared effects on pallidal dopamine induced by typical and atypical antipsychotic drugs in rats. Experiment I demonstrated that systemic administration of haloperidol (1 mg/kg; i.p.) and clozapine (20 mg/kg; i.p.) induced a significant pallidal dopamine release to about 160 and 180% of baseline, respectively. Experiment II revealed that reverse microdialysis of raclopride and clozapine using a cumulative dosing regimen did not stimulate extracellular dopamine in the globus pallidus if low (1microM) or intermediate (10 and 100 microM) concentrations were used. Only at a high concentration (1,000 microM), raclopride and clozapine induced a significant pallidal dopamine release to about 130 and 300% of baseline values, respectively. Thus, effects of typical and atypical antipsychotic drugs on pallidal dopamine were similar and thus, may not be related to their differential extrapyramidal motor side-effects liability. Furthermore, the finding that reverse microdialysis of raclopride over a wide range of concentrations did not stimulate pallidal dopamine concentrations tentatively suggests that pallidal dopamine release under basal conditions is not regulated by D2 autoreceptors.
Collapse
Affiliation(s)
- Holger Fuchs
- Abteilung Tierphysiologie, Biologisches Institut, Universität Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart, Germany
| | | |
Collapse
|
37
|
Adell A, Artigas F. The somatodendritic release of dopamine in the ventral tegmental area and its regulation by afferent transmitter systems. Neurosci Biobehav Rev 2004; 28:415-31. [PMID: 15289006 DOI: 10.1016/j.neubiorev.2004.05.001] [Citation(s) in RCA: 121] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2004] [Revised: 05/12/2004] [Accepted: 05/12/2004] [Indexed: 10/26/2022]
Abstract
The release of dopamine in the ventral tegmental area (VTA) plays an important role in the autoinhibition of the dopamine neurons of the mesocorticolimbic system through the activation of somatodendritic dopamine D2 autoreceptors. Accordingly, the intra-VTA application of dopamine D2 receptor agonists reduces the firing rate and release of dopamine in the VTA, and this control appears to possess a tonic nature because the corresponding antagonists enhance the somatodendritic release of the transmitter. In addition, the release of dopamine in the VTA is increased by potassium or veratridine depolarization and abolished by tetrodotoxin and calcium omission. Overall, it appears that the somatodendritic release of dopamine is consistently lower than that in nerve endings. Apart from intrinsic dopaminergic mechanisms, other transmitter systems such as serotonin, noradrenaline, acetylcholine, GABA and glutamate play a role in the control of the activity of dopaminergic neurons of the VTA, although the final action depends on the particular receptor involved as well as the neuronal type where it is localized. Given the involvement of the mesocorticolimbic dopaminergic systems in the pathogenesis of severe neuropsychiatric disorders such as schizophrenia, the knowledge of the factors that regulate the release of dopamine in the VTA could provide new insight into the ethiogenesis of the disease as well as its implication on the mechanisms of action of therapeutic drugs.
Collapse
Affiliation(s)
- Albert Adell
- Department of Neurochemistry, Institut d'Investigacions Biomèdiques de Barcelona, CSIC (IDIBAPS), Carrer Rosselló 161, 6th floor, E-08036 Barcelona, Spain.
| | | |
Collapse
|
38
|
Engleman EA, Ingraham CM, O'Brien CE, McBride WJ, Murphy JM. Effect of housing conditions on sulpiride-induced increases in extracellular dopamine (DA) levels in the nucleus accumbens of alcohol-preferring (P) rats. Brain Res 2004; 1022:247-50. [PMID: 15353236 DOI: 10.1016/j.brainres.2004.06.069] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/27/2004] [Indexed: 10/26/2022]
Abstract
The effect of housing conditions on sulpiride-induced increases in extracellular dopamine (DA) levels was investigated in the nucleus accumbens (NAC) of P rats. Rats were double-housed (DH) in plastic tubs, or single-housed (SH) in hanging wire cages for 12 weeks. Microdialysis in the NAC showed greater sulpiride-induced DA increases in the NAC of SH vs. DH rats, with no difference in basal levels. The data indicate that housing conditions can alter DA D(2) receptor function in the NAC.
Collapse
Affiliation(s)
- Eric A Engleman
- Department of Psychology, Institute of Psychiatric Research, Indiana University School of Medicine, Rm. M115, 791 Union Drive, Indianapolis, IN 46202, USA.
| | | | | | | | | |
Collapse
|
39
|
Nagel J, Hauber W. Reverse microdialysis of a dopamine D2 receptor antagonist alters extracellular adenosine levels in the rat nucleus accumbens. Neurochem Int 2004; 44:609-15. [PMID: 15016476 DOI: 10.1016/j.neuint.2003.10.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2003] [Accepted: 10/02/2003] [Indexed: 11/16/2022]
Abstract
Recent evidence suggests that modulation of dopaminergic transmission alters striatal levels of extracellular adenosine. The present study used reverse microdialysis of the selective dopamine D(2) receptor antagonist raclopride to investigate whether a blockade of dopamine D(2) receptors modifies extracellular adenosine concentrations in the nucleus accumbens. Results reveal that perfusion of raclopride produced an increase of dialysate adenosine which was significant with a high (10 mM) and intermediate (1 mM) drug concentration, but not with lower drug concentrations (10 and 100 microM). Thus, the present study demonstrates that a selective blockade of dopamine D(2) receptors in the nucleus accumbens produced a pronounced increase of extracellular adenosine. The cellular mechanisms underlying this effect are yet unknown. It is suggested that the increase of extracellular adenosine might be related to a homeostatic modulatory mechanism proposed to be a key function of adenosine in response to neuronal metabolic challenges.
Collapse
Affiliation(s)
- J Nagel
- Department of Animal Physiology, Institute of Biology, University of Stuttgart, Pfaffenwaldring 57, Stuttgart D-70550, Germany
| | | |
Collapse
|
40
|
Huotari M, García-Horsman JA, Karayiorgou M, Gogos JA, Männistö PT. D-amphetamine responses in catechol-O-methyltransferase (COMT) disrupted mice. Psychopharmacology (Berl) 2004; 172:1-10. [PMID: 14574438 DOI: 10.1007/s00213-003-1627-3] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2002] [Accepted: 08/13/2003] [Indexed: 11/28/2022]
Abstract
RATIONALE We have earlier found that 1). COMT inhibitors did not enhance amphetamine-induced dopamine efflux into striatal extracellular, that 2). they did not increase dopamine levels in striatal tissue and that 3). they did not potentiate amphetamine-induced turning behavior of hemiparkinsonian rats. Further, when COMT knockout mice were challenged with l-dopa or a dopamine transporter (DAT) inhibitor, an accumulation of dopamine occurred and the neurochemical and locomotor effects of l-dopa and GBR 12909 were modified accordingly. OBJECTIVE Since DAT inhibitors and amphetamine apparently have different mechanisms of action, we were interested to see how COMT knockout mice would react to d-amphetamine treatment. METHODS We measured the effects of d-amphetamine on locomotor activity and on the levels of catecholamines and their metabolites in striatal microdialysis fluid and in striatal, hypothalamic and cortical brain regions of COMT gene disrupted mice. Striatal dopamine receptor binding was also determined. RESULTS. After d-amphetamine administration, the DOPAC content in homozygous mice was 3-fold in the striatum, 17- to 18-fold in the cortex and 7- to 8-fold in the hypothalamus higher than in wild-type control mice, and there were no indications of genotypexsex interactions. However, the lack of COMT did not potentiate d-amphetamine-induced dopamine levels in brain tissue or in striatal extracellular fluid. D-amphetamine-induced (10 mg/kg) hyperlocomotion was less suppressed in male COMT knockout mice than in their wild-type counterparts. Striatal dopamine D(1) and D(2) receptor levels in male mice were not altered by COMT gene disruption. CONCLUSIONS Changes in COMT activity modulates dopamine metabolism but the behavioral effects of d-amphetamine in male mice only to a small extent, and this action does not seem to depend on the actual extracellular dopamine concentration. Nor is it mediated through compensatory changes in dopamine D(1) and D(2) receptor levels. In dopaminergic neurons, the contribution of intracellular COMT remains secondary in conditions when dopamine is released by d-amphetamine.
Collapse
Affiliation(s)
- Marko Huotari
- University of Kuopio, Department of Pharmacology and Toxicology, PO Box 1627, 70211, Kuopio, Finland
| | | | | | | | | |
Collapse
|
41
|
Rahman S, Zhang J, Engleman EA, Corrigall WA. Neuroadaptive changes in the mesoaccumbens dopamine system after chronic nicotine self-administration: A microdialysis study. Neuroscience 2004; 129:415-24. [PMID: 15501598 DOI: 10.1016/j.neuroscience.2004.08.010] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/13/2004] [Indexed: 11/25/2022]
Abstract
There is little evidence to date to indicate if mesoaccumbens dopamine function at the neurochemical level is altered during early abstinence from chronic i.v. nicotine self-administration. Thus, a quantitative microdialysis (no-net-flux) approach was used to measure basal extracellular concentrations and extraction fractions of dopamine in the nucleus accumbens (ACB) of rats that self-administered nicotine i.v. for 25 days, as well as in rats serving as yoked comparison groups (yoked nicotine and yoked saline). After 24-48 h of the final self-administration session, there was a significant reduction in basal extracellular dopamine levels in the ACB of the self-administration group compared with the yoked saline group (1.35+/-0.15 nM versus 3.70+/-0.28 nM). The basal extracellular dopamine levels in the yoked nicotine group (1.46+/-0.20 nM) were not significantly different compared with the nicotine self-administration group. The in vivo extraction fraction of dopamine, an indirect measure of dopamine uptake, was significantly increased in the nicotine self-administration (86%) and yoked nicotine (91%) groups compared with the yoked saline group (77%). In addition, a marked reduction in the elevation of extracellular dopamine levels in the ACB occurred after a nicotine challenge as measured by conventional microdialysis in the self-administration (112% of basal) and yoked nicotine (121% of basal) groups as compared with a yoked saline (154% of basal) group. The reduced basal ACB dopamine levels in the nicotine groups during early abstinence appears to be due to increased clearance, suggesting increased dopamine uptake is occurring as a result of the chronic nicotine treatment. The reduced elevation of extracellular dopamine levels in the ACB upon nicotine challenge suggests a functional desensitization or downregulation phenomenon involving acetylcholine receptors (nicotinic nAChRs). Overall, these results provide clear evidence for a neuroadaptive change that alters dopamine transmission in the ACB during abstinence from chronic i.v. nicotine exposure.
Collapse
Affiliation(s)
- S Rahman
- Smoking and Nicotine Dependence Research, Neuroscience Department, Centre for Addiction and Mental Health, University of Toronto, 33 Russell Street, Toronto, Ontario, M5S 2S1 Canada.
| | | | | | | |
Collapse
|
42
|
Rahman S, Zhang J, Engleman E, Corrigall W. Neuroadaptive changes in the mesoaccumbens dopamine system after chronic nicotine self-administration: A microdialysis study. Neuroscience 2004. [DOI: https://doi.org/10.1016/j.neuroscience.2004.08.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
43
|
Engleman EA, McBride WJ, Li TK, Lumeng L, Murphy JM. Ethanol drinking experience attenuates (-)sulpiride-induced increases in extracellular dopamine levels in the nucleus accumbens of alcohol-preferring (P) rats. Alcohol Clin Exp Res 2003; 27:424-31. [PMID: 12658107 DOI: 10.1097/01.alc.0000056618.57931.a5] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND The reinforcing properties of ethanol may be partly mediated through the mesolimbic dopamine (DA) system. This study examines the effects of local application of the DA D(2) receptor antagonist (-)sulpiride (SUL) on ethanol drinking of alcohol-preferring (P) rats, and extracellular DA levels in the nucleus accumbens (NAc) of P rats that were either ethanol-naive or had been chronically drinking ethanol. METHODS Microdialysis was used to sample NAc DA levels, and reverse microdialysis was used to locally administer the D(2) antagonist (-)sulpiride (SUL) into the NAc of adult female P rats that were either drinking ethanol (n = 17) or were ethanol-naive (n = 24). Stable intake of 15% (v/v) ethanol (>/=0.75 g/kg) was established for the ethanol-drinking group in daily 1-hr access periods over a minimum of 4 weeks before surgery. Naive and ethanol-drinking rats were implanted with bilateral guide cannulae aimed 4 mm above the NAc shell. After recovery from surgery, microdialysis probes (active area = 2 mm) were inserted bilaterally into the NAc. Two days later, rats in the ethanol-drinking and naive groups were each divided into two groups; one group was bilaterally perfused (1.0 microl/min) with artificial cerebrospinal fluid (aCSF) and the other group was further divided into three subgroups that were perfused with aCSF + either 50, 100, or 200 microM SUL for 240 min. During the last 60 min of perfusion, the ethanol-drinking rats were given their daily 1-hr ethanol access period. Following ethanol access, the aCSF + SUL subgroups were then given aCSF only. The entire perfusion procedure was repeated 24 hr later, but the aCSF only and aCSF + SUL group treatment conditions were transposed. RESULTS In ethanol-drinking rats, 100 and 200 microM SUL increased extracellular NAc DA levels to approximately 200% of basal values, but did not significantly alter ethanol intake. In ethanol-naive P rats, 100 and 200 microM SUL increased extracellular NAc DA levels significantly more (450% of basal; p < 0.05) than in the ethanol-drinking group. CONCLUSIONS The findings are consistent with the hypothesis that ethanol-drinking experience causes a desensitization or a down-regulation of D(2) autoreceptors in the NAc of P rats.
Collapse
Affiliation(s)
- Eric A Engleman
- Department of Psychology, Purdue School of Science, 402 N. Blackford Street, IUPUI, Indianapolis, IN 46202-3275, USA
| | | | | | | | | |
Collapse
|
44
|
Abstract
1. Microdialysis is an established technique for studying physiological, pharmacological and pathological changes of a wide range of low molecular weight substances in the brain extracellular fluid. Many studies have proven its sensitivity in sampling the extracellular space in discrete brain locations, such as the striatum, and monitoring the action of exogenous substances. 2. The two main areas of application of microdialysis are the recovery of endogenous substances, primarily the neurotransmitters, and the infusion of drugs through the microdialysis cannula (retrodialysis). 3. Microdialysis in awake animals is the tool of choice for studying the relationship between changes in behaviour and neurotransmitters in certain brain areas. In addition, the concomitant recording of the electroencephalogram at the site of microdialysis has been shown to be extremely useful in determining the role of certain neurotransmitters in paroxysmal activity. 4. Clinical applications of microdialysis have included monitoring of ischaemic injury, subarachnoid haemorrhage, trauma and epilepsy. With the recent availability of standardized equipment, the use of microdialysis in the neurological clinic is likely to become more common.
Collapse
Affiliation(s)
- James A Bourne
- Department of Physiology, Monash University, Melbourne, Victoria, Australia.
| |
Collapse
|
45
|
Pickel VM, Chan J, Nirenberg MJ. Region-specific targeting of dopamine D2-receptors and somatodendritic vesicular monoamine transporter 2 (VMAT2) within ventral tegmental area subdivisions. Synapse 2002; 45:113-24. [PMID: 12112404 DOI: 10.1002/syn.10092] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Throughout the ventral tegmental area (VTA), dopamine is packaged within subcellular organelles by the vesicular monoamine transporter-2 (VMAT2). Somatodendritically released dopamine in this region binds to the D2 receptor (D2R) to modulate ongoing neurotransmission. Although autoregulation of mesocortical dopaminergic neurons in the parabrachial VTA (PB-VTA) is known to be less efficacious than that of mesolimbic dopaminergic neurons in the paranigral (PN-VTA), the cellular basis for this regional heterogeneity is not known. For this reason, we used electron microscopic immunocytochemistry to determine the subcellular localization of the dopamine storage vesicles (identified by the presence of VMAT2) in relation to the D2R in these VTA subdivisions. In both regions, D2R immunoreactivity was principally located on extrasynaptic dendritic plasma membranes near excitatory-type synapses. Equivalent percentages (72 and 74%) of the D2R-labeled dendrites in each region contained VMAT2-immunoreactive tubulovesicles. Of the total VMAT2-labeled dendrites, however, a significantly lower percentage in the PB-VTA (26%) than in the PN-VTA (38%) contained D2R labeling. In contrast, a significantly higher number of VMAT2 immunogold-silver deposits was seen within individual dendrites in the PB-VTA than in PN-VTA. In both regions, D2R immunoreactivity was also detected in VMAT2-negative axon terminals that formed synapses on dendrites containing VMAT2. Our results are the first to demonstrate that within VTA neurons and their afferents the D2R is strategically positioned for activation by dopamine released from dendritic storage vesicles. These findings also suggest that the potential for D2R activation may affect the expression levels of VMAT2 in VTA dendrites.
Collapse
Affiliation(s)
- Virginia M Pickel
- Department of Neurology and Neuroscience, Weill Medical College of Cornell University, New York, New York 10021, USA.
| | | | | |
Collapse
|
46
|
Jedynak JP, Ali SF, Haycock JW, Hope BT. Acute administration of cocaine regulates the phosphorylation of serine-19, -31 and -40 in tyrosine hydroxylase. J Neurochem 2002; 82:382-8. [PMID: 12124439 DOI: 10.1046/j.1471-4159.2002.00982.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Acute cocaine can inhibit catecholamine biosynthesis by regulating the enzymatic activity of tyrosine hydroxylase via alterations in the phosphorylation state of the enzyme. The mechanisms underlying acute cocaine-dependent regulation of tyrosine hydroxylase phosphorylation have not been determined. In this study, 0, 15 or 30 mg/kg cocaine was administered intraperitoneally to rats and the phosphorylation state of tyrosine hydroxylase in the brain was examined using antibodies specific for the phosphorylated forms of serine-19, -31 and -40 in tyrosine hydroxylase. In the caudate and nucleus accumbens, cocaine dose-dependently decreased the levels of phosphorylated serine-19, -31 and -40. In the ventral tegmental area, the levels of phosphorylated serine-19, but not serine-31 and -40, were decreased by 15 and 30 mg/kg cocaine. In the amygdala, the levels of phosphorylated serine-19, but not serine-31 or -40, were decreased. The functional effects of these alterations in phosphorylation state were assessed by measuring tyrosine hydroxylase activity in vivo (accumulation of DOPA after administration of the decarboxylase inhibitor NSD-1015). Acute administration of 30 mg/kg cocaine significantly decreased l-DOPA production in caudate and accumbens but not in amygdala. These data suggest that the phosphorylation of serine-31 or -40, but not serine-19, is involved in the regulation of tyrosine hydroxylase activity by acute cocaine.
Collapse
Affiliation(s)
- Jakub P Jedynak
- Behavioral Neuroscience Branch, The National Institute on Drug Abuse, Intramural Research Program, Baltimore, Maryland 21224, USA
| | | | | | | |
Collapse
|
47
|
Mengual E, Pickel VM. Ultrastructural immunocytochemical localization of the dopamine D2 receptor and tyrosine hydroxylase in the rat ventral pallidum. Synapse 2002; 43:151-62. [PMID: 11793420 DOI: 10.1002/syn.10033] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The mesopallidal dopamine system plays a role in locomotor activity and reward. To understand the potential contribution of the dopamine D2 receptor (D2R) to the action of dopamine in the ventral pallidum (VP), we used electron microscopic immunocytochemistry to examine the cellular and subcellular localization of an antipeptide antiserum against the D2R in both ventromedial and dorsolateral VP compartments. In each region the majority of the total D2R-labeled profiles (n = 1,132) were axon terminals (55%) and small unmyelinated axons (27%). These terminals were often apposed to other axon terminals or dendrites and formed almost exclusively symmetric, inhibitory-type axodendritic synapses. Immunogold D2R labeling in axon terminals was seen on the plasmalemma and membranes of nearby synaptic vesicles. In ventral pallidal sections processed for dual detection of D2R peptide and the catecholamine-synthesizing enzyme tyrosine hydroxylase (TH), D2R labeling was detected in a few axons and axon terminals containing TH immunoreactivity as well as in axons contacted by TH-labeled terminals. In most cases, however, the D2R-labeled profiles were located at a distance from small axons and terminals containing TH. Our results provide the first ultrastructural evidence that D2Rs in the two VP subterritories are strategically located for primary involvement in modulation of the presynaptic release of nondopaminergic inhibitory transmitters. They also suggest that in this region the presynaptic D2 receptors are 1) minimally involved in autoregulation of dopaminergic transmission, and 2) differentially activated by dopamine, depending in part on levels and distance from release sites.
Collapse
Affiliation(s)
- Elisa Mengual
- Division of Neurobiology, Department of Neurology and Neuroscience, Weill Medical College of Cornell University, 411 East 69th St., New York, NY 10021, USA
| | | |
Collapse
|
48
|
Rahman S, McBride WJ. D1-D2 dopamine receptor interaction within the nucleus accumbens mediates long-loop negative feedback to the ventral tegmental area (VTA). J Neurochem 2001. [DOI: https://doi.org/10.1046/j.1471-4159.2001.00326.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
49
|
Lipovac MN, Hashim A, Sershen H, Allen D, Cooper T, Czobor P, Lajtha A. Differences in nicotine-induced dopamine release and nicotine pharmacokinetics between Lewis and Fischer 344 rats. Neurochem Res 2001; 26:609-17. [PMID: 11519721 DOI: 10.1023/a:1010979018217] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Studies have shown a greater preference for the self-administration of drugs such as nicotine and cocaine in the Lewis rat strain than in the Fischer 344 strain. We examined some factors that could contribute to such a difference. The baseline level of extracellular dopamine in nucleus accumbens shell was about 3-times higher in Fischer rats than in Lewis rats (3.18 +/- 0.26 vs. 1.09 +/- 0.14 pg/ sample). Nicotine (50-100 microg/kg)-induced release of dopamine, expressed in absolute terms, was similar in the two strains. Dopamine release expressed in relative terms (as percent of baseline), however, was significantly greater in Lewis rats than in Fischer rats at 30 min after the first nicotine injection. We suggest that the relative increase is of more influence than the absolute level for determining preference; a lower physiological extracellular dopamine level thus represent a risk factor for increased preference. Amphetamine-induced dopamine release expressed in relative terms was not greater in the Lewis strain. In the initial time period of the microdialysis experiments, a sharper peak in nicotine-induced accumbal dopamine release in Lewis and a less but more sustained release in Fischer rats was observed. This release pattern paralleled the faster clearance of nicotine from blood of Lewis compared to Fischer rats. In tissue slices the electrically induced dopamine release was highest in the nucleus accumbens and lowest in the ventral tegmentum. A significant effect of nicotine was lowering the electrically induced release of dopamine in frontal cortex slices from Fischer brain and increasing this dopamine release in the ventral tegmentum of Lewis brain slices indicating that the ventral tegmentum, an area controlling dopamine release in the accumbens, is more responsive to nicotine in the Lewis rat. Nicotine levels tended to be more sustained in Fischer rats in different brain regions, although the difference in nicotine levels between the strains was not significant at any time period. Several factors contribute to nicotine preference, including the endogenous dopamine level, and the sensitivity of ventral tegmentum neurons to nicotine-induced dopamine release. Strain differences in pharmacokinetics of nicotine may also play a role.
Collapse
|
50
|
Rahman S, McBride WJ. D1-D2 dopamine receptor interaction within the nucleus accumbens mediates long-loop negative feedback to the ventral tegmental area (VTA). J Neurochem 2001; 77:1248-55. [PMID: 11389175 DOI: 10.1046/j.1471-4159.2001.00326.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The objective of the present study was to examine the effects of perfusion of dopamine (DA) D1- and D2-like receptor agonists in the nucleus accumbens (ACB) on the long-loop negative feedback regulation of mesolimbic somatodendritic DA release in the ventral tegmental area (VTA) of Wistar rats employing ipsilateral dual probe in vivo microdialysis. Perfusion of the ACB for 60 min with the D1-like receptor agonist SKF 38393 (SKF, 1-100 microM) dose-dependently reduced the extracellular levels of DA in the ACB, whereas the extracellular levels of DA in the VTA were not changed. Similarly, application of the D2-like receptor agonist quinpirole (Quin, 1-100 microM) through the microdialysis probe in the ACB reduced the extracellular levels of DA in the ACB in a concentration-dependent manner, whereas extracellular levels of DA in the VTA were not altered. Co-application of SKF (100 microM) and Quin (100 microM) produced concomitant reductions in the extracellular levels of DA in the ACB and VTA. The reduction in extracellular levels of DA in the ACB and VTA produced by co-infusion of SKF and Quin was reversed in the presence of either 100 microM SCH 23390 (D1-like antagonist) or 100 microM sulpiride (D2-like antagonist). Overall, the results suggest that (a) activation of dopamine D1- or D2-like receptors can independently regulate local terminal DA release in the ACB, whereas stimulation of both subtypes is required for activation of the negative feedback pathway to the VTA.
Collapse
Affiliation(s)
- S Rahman
- Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis 46202-4887, USA
| | | |
Collapse
|