1
|
Liu XY, Zheng LF, Fan YY, Shen QY, Qi Y, Li GW, Sun Q, Zhang Y, Feng XY, Zhu JX. Activation of dopamine D 2 receptor promotes pepsinogen secretion by suppressing somatostatin release from the mouse gastric mucosa. Am J Physiol Cell Physiol 2022; 322:C327-C337. [PMID: 34986020 DOI: 10.1152/ajpcell.00385.2021] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 01/04/2022] [Indexed: 12/14/2022]
Abstract
In vivo administration of dopamine (DA) receptor (DR)-related drugs modulate gastric pepsinogen secretion. However, DRs on gastric pepsinogen-secreting chief cells and DA D2 receptor (D2R) on somatostatin-secreting D cells were subsequently acquired. In this study, we aimed to further investigate the local effect of DA on gastric pepsinogen secretion through DRs expressed on chief cells or potential D2Rs expressed on D cells. To elucidate the modulation of DRs in gastric pepsinogen secretion, immunofluorescence staining, ex vivo incubation of gastric mucosa isolated from normal and D2R-/- mice were conducted, accompanied by measurements of pepsinogen or somatostatin levels using biochemical assays or enzyme-linked immunosorbent assays. D1R, D2R, and D5R-immunoreactivity (IR) were observed on chief cells in mouse gastric mucosa. D2R-IR was widely distributed on D cells from the corpus to the antrum. Ex vivo incubation results showed that DA and the D1-like receptor agonist SKF38393 increased pepsinogen secretion, which was blocked by the D1-like receptor antagonist SCH23390. However, D2-like receptor agonist quinpirole also significantly increased pepsinogen secretion, and D2-like receptor antagonist sulpiride blocked the promotion of DA. Besides, D2-like receptors exerted an inhibitory effect on somatostatin secretion, in contrast to their effect on pepsinogen secretion. Furthermore, D2R-/- mice showed much lower basal pepsinogen secretion but significantly increased somatostatin release and an increased number of D cells in gastric mucosa. Only SKF38393, not quinpirole, increased pepsinogen secretion in D2R-/- mice. DA promotes gastric pepsinogen secretion directly through D1-like receptors on chief cells and indirectly through D2R-mediated suppression of somatostatin release.
Collapse
MESH Headings
- Animals
- Chief Cells, Gastric/drug effects
- Chief Cells, Gastric/metabolism
- Dopamine Agonists/pharmacology
- Dopamine Antagonists/pharmacology
- Male
- Mice, Inbred C57BL
- Mice, Knockout
- Pepsinogen A/metabolism
- Quinpirole/pharmacology
- Receptors, Dopamine D1/agonists
- Receptors, Dopamine D1/antagonists & inhibitors
- Receptors, Dopamine D1/metabolism
- Receptors, Dopamine D2/agonists
- Receptors, Dopamine D2/genetics
- Receptors, Dopamine D2/metabolism
- Secretory Pathway
- Somatostatin/metabolism
- Somatostatin-Secreting Cells/drug effects
- Somatostatin-Secreting Cells/metabolism
- Mice
Collapse
Affiliation(s)
- Xiao-Yu Liu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing, People's Republic of China
| | - Li-Fei Zheng
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing, People's Republic of China
| | - Yan-Yan Fan
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing, People's Republic of China
| | - Qian-Ying Shen
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing, People's Republic of China
| | - Yao Qi
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing, People's Republic of China
| | - Guang-Wen Li
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing, People's Republic of China
| | - Qi Sun
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing, People's Republic of China
| | - Yue Zhang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing, People's Republic of China
| | - Xiao-Yan Feng
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing, People's Republic of China
| | - Jin-Xia Zhu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing, People's Republic of China
| |
Collapse
|
2
|
Deciphering Spinal Endogenous Dopaminergic Mechanisms That Modulate Micturition Reflexes in Rats with Spinal Cord Injury. eNeuro 2021; 8:ENEURO.0157-21.2021. [PMID: 34244339 PMCID: PMC8328273 DOI: 10.1523/eneuro.0157-21.2021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 06/03/2021] [Accepted: 06/30/2021] [Indexed: 01/23/2023] Open
Abstract
Spinal neuronal mechanisms regulate recovered involuntary micturition after spinal cord injury (SCI). It was recently discovered that dopamine (DA) is synthesized in the rat injured spinal cord and is involved in lower urinary tract (LUT) activity. To fully understand the role of spinal DAergic machinery in micturition, we examined urodynamic responses in female rats during pharmacological modulation of the DA pathway. Three to four weeks after complete thoracic SCI, the DA precursor L-DOPA administered intravenously during bladder cystometrogram (CMG) and external urethral sphincter (EUS) electromyography (EMG) reduced bladder overactivity and increased the duration of EUS bursting, leading to remarkably improved voiding efficiency. Apomorphine (APO), a non-selective DA receptor (DR) agonist, or quinpirole, a selective DR2 agonist, induced similar responses, whereas a specific DR2 antagonist remoxipride alone had only minimal effects. Meanwhile, administration of SCH 23390, a DR1 antagonist, reduced voiding efficiency by increasing tonic EUS activity and shortening the EUS bursting period. Unexpectedly, SKF 38393, a selective DR1 agonist, increased EUS tonic activity, implying a complicated role of DR1 in LUT function. In metabolic cage assays, subcutaneous administration of quinpirole decreased spontaneous voiding frequency and increased voiding volume; L-DOPA and APO were inactive possibly because of slow entry into the CNS. Collectively, tonically active DR1 in SCI rats inhibit urine storage and enhance voiding by differentially modulating EUS tonic and bursting patterns, respectively, while pharmacologic activation of DR2, which are normally silent, improves voiding by enhancing EUS bursting. Thus, enhancing DA signaling achieves better detrusor-sphincter coordination to facilitate micturition function in SCI rats.
Collapse
|
3
|
Midroit M, Chalençon L, Renier N, Milton A, Thevenet M, Sacquet J, Breton M, Forest J, Noury N, Richard M, Raineteau O, Ferdenzi C, Fournel A, Wesson DW, Bensafi M, Didier A, Mandairon N. Neural processing of the reward value of pleasant odorants. Curr Biol 2021; 31:1592-1605.e9. [PMID: 33607032 DOI: 10.1016/j.cub.2021.01.066] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 01/07/2021] [Accepted: 01/19/2021] [Indexed: 02/07/2023]
Abstract
Pleasant odorants are represented in the posterior olfactory bulb (pOB) in mice. How does this hedonic information generate odor-motivated behaviors? Using optogenetics, we report here that stimulating the representation of pleasant odorants in a sensory structure, the pOB, can be rewarding, self-motivating, and is accompanied by ventral tegmental area activation. To explore the underlying neural circuitry downstream of the olfactory bulb (OB), we use 3D high-resolution imaging and optogenetics and determine that the pOB preferentially projects to the olfactory tubercle, whose increased activity is related to odorant attraction. We further show that attractive odorants act as reinforcers in dopamine-dependent place preference learning. Finally, we extend those findings to humans, who exhibit place preference learning and an increase BOLD signal in the olfactory tubercle in response to attractive odorants. Thus, strong and persistent attraction induced by some odorants is due to a direct gateway from the pOB to the reward system.
Collapse
Affiliation(s)
- Maëllie Midroit
- CNRS, UMR 5292, INSERM, U1028, Lyon Neuroscience Research Center, Neuroplasticity and Neuropathology of Olfactory Perception Team, Lyon 69000, France; University Lyon, Lyon, 69000, France; University Lyon 1, Villeurbanne 69000, France
| | - Laura Chalençon
- CNRS, UMR 5292, INSERM, U1028, Lyon Neuroscience Research Center, Neuroplasticity and Neuropathology of Olfactory Perception Team, Lyon 69000, France; University Lyon, Lyon, 69000, France; University Lyon 1, Villeurbanne 69000, France
| | - Nicolas Renier
- Sorbonne Universités, Paris Brain Institute, ICM, Inserm, CNRS, Paris, France
| | - Adrianna Milton
- Department of Neurosciences, Case Western Reserve University, 2109 Adelbert Road, Cleveland, OH 44106, USA
| | - Marc Thevenet
- CNRS, UMR 5292, INSERM, U1028, Lyon Neuroscience Research Center, Neuroplasticity and Neuropathology of Olfactory Perception Team, Lyon 69000, France; University Lyon, Lyon, 69000, France; University Lyon 1, Villeurbanne 69000, France
| | - Joëlle Sacquet
- CNRS, UMR 5292, INSERM, U1028, Lyon Neuroscience Research Center, Neuroplasticity and Neuropathology of Olfactory Perception Team, Lyon 69000, France; University Lyon, Lyon, 69000, France; University Lyon 1, Villeurbanne 69000, France
| | - Marine Breton
- CNRS, UMR 5292, INSERM, U1028, Lyon Neuroscience Research Center, Neuroplasticity and Neuropathology of Olfactory Perception Team, Lyon 69000, France; University Lyon, Lyon, 69000, France; University Lyon 1, Villeurbanne 69000, France
| | - Jérémy Forest
- CNRS, UMR 5292, INSERM, U1028, Lyon Neuroscience Research Center, Neuroplasticity and Neuropathology of Olfactory Perception Team, Lyon 69000, France; University Lyon, Lyon, 69000, France; University Lyon 1, Villeurbanne 69000, France
| | - Norbert Noury
- CNRS, UMR5270, Institute Nanotechnology Lyon, Biomedical Sensors Group, University of Lyon 1, Villeurbanne 69621, France
| | - Marion Richard
- CNRS, UMR 5292, INSERM, U1028, Lyon Neuroscience Research Center, Neuroplasticity and Neuropathology of Olfactory Perception Team, Lyon 69000, France; University Lyon, Lyon, 69000, France; University Lyon 1, Villeurbanne 69000, France
| | - Olivier Raineteau
- University Lyon, Université Claude Bernard Lyon 1, Inserm, Stem Cell and Brain Research Institute U1208, 69500 Bron, France
| | - Camille Ferdenzi
- CNRS, UMR 5292, INSERM, U1028, Lyon Neuroscience Research Center, Neuroplasticity and Neuropathology of Olfactory Perception Team, Lyon 69000, France; University Lyon, Lyon, 69000, France; University Lyon 1, Villeurbanne 69000, France
| | - Arnaud Fournel
- CNRS, UMR 5292, INSERM, U1028, Lyon Neuroscience Research Center, Neuroplasticity and Neuropathology of Olfactory Perception Team, Lyon 69000, France; University Lyon, Lyon, 69000, France; University Lyon 1, Villeurbanne 69000, France
| | - Daniel W Wesson
- Department of Pharmacology & Therapeutics, University of Florida, 1200 Newell Drive, Gainesville, FL 32610, USA
| | - Moustafa Bensafi
- CNRS, UMR 5292, INSERM, U1028, Lyon Neuroscience Research Center, Neuroplasticity and Neuropathology of Olfactory Perception Team, Lyon 69000, France; University Lyon, Lyon, 69000, France; University Lyon 1, Villeurbanne 69000, France
| | - Anne Didier
- CNRS, UMR 5292, INSERM, U1028, Lyon Neuroscience Research Center, Neuroplasticity and Neuropathology of Olfactory Perception Team, Lyon 69000, France; University Lyon, Lyon, 69000, France; University Lyon 1, Villeurbanne 69000, France
| | - Nathalie Mandairon
- CNRS, UMR 5292, INSERM, U1028, Lyon Neuroscience Research Center, Neuroplasticity and Neuropathology of Olfactory Perception Team, Lyon 69000, France; University Lyon, Lyon, 69000, France; University Lyon 1, Villeurbanne 69000, France.
| |
Collapse
|
4
|
Kramar CP, Castillo-Díaz F, Gigante ED, Medina JH, Barbano MF. The late consolidation of an aversive memory is promoted by VTA dopamine release in the dorsal hippocampus. Eur J Neurosci 2021; 53:841-851. [PMID: 33617053 DOI: 10.1111/ejn.15076] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 11/10/2020] [Accepted: 11/24/2020] [Indexed: 11/30/2022]
Abstract
The hippocampus has been implicated in the processing and storage of aversive memories but the precise mechanisms by which these memories persist in time remain elusive. We have demonstrated that dopaminergic neurotransmission in the dorsal hippocampus regulates the long-term storage of both appetitive and aversive memories at a critical time point known as "late consolidation" (12 hr after the learning experience). This modulation appears to have opposite effects depending on the valence of the stimuli, with hippocampal dopamine release peaking immediately and 13-17 hr after a rewarding experience. Here, we determined the release pattern of hippocampal dopamine following an aversive experience, in order to better understand this opposite modulation process. We observed significant increases in dopamine levels at several times (6-8, 11-12, and 15 hr) after subjecting rats to a conditioned place aversion (CPA) task with the aversive agent lithium chloride (LiCl). Early pharmacological blockade of hippocampal DA receptors impaired CPA memory consolidation. In addition and consistent with previous findings showing that late post-training infusions of dopaminergic agents into the hippocampus modulate the long-term storage of aversive memories, we found that the photostimulation of dopaminergic VTA fibers in the dorsal hippocampus 11-12 hr after CPA training was enough to transform a short-lasting long-term memory into a long-lasting one. The fact that the persistence of an aversive memory can still be affected several hours after the learning experience opens new avenues to develop behavioral and pharmacological strategies for the treatment of a variety of mental disorders.
Collapse
Affiliation(s)
- Cecilia P Kramar
- Instituto de Biología Celular y Neurociencias (CONICET-UBA), Facultad de Medicina, UBA, Buenos Aires, Argentina
| | - Fernando Castillo-Díaz
- Instituto de Biología Celular y Neurociencias (CONICET-UBA), Facultad de Medicina, UBA, Buenos Aires, Argentina
| | - Eduardo D Gigante
- National Institute on Drug Abuse (NIDA/NIH), Neuronal Networks Section, Baltimore, MD, USA
| | - Jorge H Medina
- Instituto de Biología Celular y Neurociencias (CONICET-UBA), Facultad de Medicina, UBA, Buenos Aires, Argentina
| | - M Flavia Barbano
- Instituto de Biología Celular y Neurociencias (CONICET-UBA), Facultad de Medicina, UBA, Buenos Aires, Argentina.,National Institute on Drug Abuse (NIDA/NIH), Neuronal Networks Section, Baltimore, MD, USA
| |
Collapse
|
5
|
Qiao Y, Brodnik ZD, Zhao S, Trueblood CT, Li Z, Tom VJ, España RA, Hou S. Spinal Dopaminergic Mechanisms Regulating the Micturition Reflex in Male Rats with Complete Spinal Cord Injury. J Neurotrauma 2021; 38:803-817. [PMID: 33297828 DOI: 10.1089/neu.2020.7284] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Traumatic spinal cord injury (SCI) often causes micturition dysfunction. We recently discovered a low level of spinally-derived dopamine (DA) that regulates recovered bladder and sphincter reflexes in SCI female rats. Considering substantial sexual dimorphic features in the lower urinary tract, it is unknown if the DA-ergic mechanisms act in the male. Histological analysis showed a similar distribution of tyrosine hydroxylase (TH)+ neurons in the lower cord of male rats and the number increased following thoracic SCI. Subsequently, focal electrical stimulation in slices obtained from L6/S1 spinal segments of SCI rats elicited detectable DA release with fast scan cyclic voltammetry. Using bladder cystometrogram and external urethral sphincter (EUS) electromyography in SCI male rats, intravenous (i.v.) administration of SCH 23390, a D1-like receptor (DR1) antagonist, induced significantly increased tonic EUS activity and a trend of increased residual volume, whereas activation of these receptors with SKF 38393 did not influence the reflex. Meanwhile, blocking spinal D2-like receptors (DR2) with remoxipride had no effect but stimulating these receptors with quinpirole elicited EUS bursting to increase voiding volume. Further, intrathecal delivery of SCH 23390 and quinpirole resulted in similar responses to those with i.v. delivery, respectively, which indicates the central action regardless of delivery route. In addition, metabolic cage assays showed that quinpirole increased the voiding frequency and total voiding volume in spontaneous micturition. Collectively, spinal DA-ergic machinery regulates recovered micturition reflex following SCI in male rats; spinal DR1 tonically suppress tonic EUS activity to enable voiding and activation of DR2 facilitates voiding.
Collapse
Affiliation(s)
- Yuan Qiao
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA.,Department of Anatomy, Shandong University School of Basic Medical Sciences, Ji'nan, China
| | - Zachary D Brodnik
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Shunyi Zhao
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Cameron T Trueblood
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Zhenzhong Li
- Department of Anatomy, Shandong University School of Basic Medical Sciences, Ji'nan, China
| | - Veronica J Tom
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Rodrigo A España
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Shaoping Hou
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| |
Collapse
|
6
|
Kim ES, Lattal KM. Context-Dependent and Context-Independent Effects of D1 Receptor Antagonism in the Basolateral and Central Amygdala during Cocaine Self-Administration. eNeuro 2019; 6:ENEURO.0203-19.2019. [PMID: 31358512 PMCID: PMC6712201 DOI: 10.1523/eneuro.0203-19.2019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 07/01/2019] [Accepted: 07/09/2019] [Indexed: 11/21/2022] Open
Abstract
One way that drugs of abuse perturb the dopamine system is by triggering large amounts of extracellular dopamine to efflux into limbic regions. The basolateral (BLA) and central (CeA) nuclei of the amygdala have been shown to play distinct roles in value representation of primary and conditioned reward. However, the precise role of dopaminergic receptors in the BLA and the CeA during reward-related behaviors remains to be determined. Here we investigate the effects of dopamine D1 receptor blockade in the BLA and the CeA during asymptotic performance of cocaine self-administration and in a novel application of contextual renewal under continued access conditions. After more than three weeks of chained seek-take self-administration of cocaine, male Long Evans rats were given a bilateral intra-BLA or intra-CeA infusion of the D1 antagonist SCH-23390 (2 µg/0.3 µl) for multiple days. Intra-BLA D1 receptor blockade before, but not after the self-administration session, gradually suppressed drug seeking and taking responses and persisted with a change in context with continued D1 blockade. In contrast, intra-CeA D1 receptor blockade caused a rapid reduction in self-administration that showed renewal with a change in context with continued D1 blockade. Further, conditioned place aversion developed with intra-BLA but not intra-CeA infusions. Collectively, these results demonstrate that dopamine D1 receptors in the BLA and CeA both contribute to drug seeking and taking, but may do so through distinct mechanisms.
Collapse
Affiliation(s)
- Earnest S Kim
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR 97239-3098
| | - K Matthew Lattal
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR 97239-3098
| |
Collapse
|
7
|
Rothwell ES, Mendoza SP, Ragen BJ, Bales KL. Dopamine D1-like receptors regulate agonistic components of pair bond maintenance behaviors in male titi monkeys (Callicebus cupreus). Psychoneuroendocrinology 2019; 106:259-267. [PMID: 31022585 PMCID: PMC7430189 DOI: 10.1016/j.psyneuen.2019.04.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 04/02/2019] [Accepted: 04/09/2019] [Indexed: 01/12/2023]
Abstract
Several neurobiological mechanisms are implicated in the formation of selective pair bonds in socially monogamous mammals, however much less is known about the mechanisms that underlie the long-term behavioral maintenance of these bonds. In prairie voles (Microtus ochrogaster), agonistic behavior that contributes to pair bond maintenance are regulated by dopamine activity at D1-like receptors (D1R) within the mesocorticolimbic system. Evidence suggests D1Rs similarly regulate the behavioral components of pair bond maintenance in socially monogamous titi monkeys (Callicebus cupreus); however, evaluation with behavioral pharmacology is necessary to evaluate this hypothesis. In the current study we evaluated the role of D1Rs in behavioral components of pair bond maintenance in captive male titi monkeys (N = 8). We administered two doses of a D1R selective antagonist, SCH23390, (0.1 mg/kg, 0.01 mg/kg) or saline vehicle to male titi monkeys and presented pairs with a simulated intruder monkey via the use of a mirror stimulus. The non-reflective back of the mirror stimulus was used for control sessions. We video recorded responses to the five-minute stimulus presentations and later scored for arousal and agonistic behaviors relevant to mate guarding as well as affiliative behavior between the pair mates. We also conducted a locomotor assessment to evaluate the potential side effect for SCH23390 of impaired locomotion. Finally, we collected blood samples at the end of each session to assay for plasma cortisol responses. We found evidence of locomotor impairment only with the high dose of SCH23390, and therefore analyses were conducted comparing only test sessions where low dose SCH23390 and saline were administered. With saline administration, males displayed more agonistic behavior via back arching and tail lashing as well as restraining their female partners when viewing the mirror compared to the back of the mirror. D1R antagonist treatment attenuated these agonistic behaviors indicative of mate guarding when males viewed the mirror. Results also indicated that this reduction in agonistic behavior occurred without evidence of overall behavioral blunting or generally reduced social interest. Likewise changes in agonistic behavior were not driven by differences in HPA activity across testing sessions. Mate-directed affiliative behavior, including lip smacks and approaches to female partners, were not altered by D1R antagonist treatment. Dyadic social contact was higher with D1R antagonist treatment, but this was due to a reduction in contact termination by the treated males, which was typically followed by an approach or arousal display to the simulated intruder. These results provide further evidence that D1R activity regulates mate guarding behaviors in titi monkeys and suggests that the dopamine system plays a similar role in the agonistic behavioral components of pair bond maintenance behavior in non-human primates and rodents.
Collapse
Affiliation(s)
- Emily S Rothwell
- California National Primate Research Center, University of California- Davis, One Shields Avenue, Davis, CA, 95616, USA; Animal Behavior Graduate Group, University of California- Davis, One Shields Avenue, Davis, CA, 95616, USA.
| | - Sally P Mendoza
- Department of Psychology, University of California- Davis, One Shields Avenue, Davis, CA, 95616, USA
| | - Benjamin J Ragen
- Department of Psychology, University of California- Davis, One Shields Avenue, Davis, CA, 95616, USA
| | - Karen L Bales
- California National Primate Research Center, University of California- Davis, One Shields Avenue, Davis, CA, 95616, USA; Animal Behavior Graduate Group, University of California- Davis, One Shields Avenue, Davis, CA, 95616, USA; Department of Psychology, University of California- Davis, One Shields Avenue, Davis, CA, 95616, USA
| |
Collapse
|
8
|
Drakakis G, Wafford KA, Brewerton SC, Bodkin MJ, Evans DA, Bender A. Polypharmacological in Silico Bioactivity Profiling and Experimental Validation Uncovers Sedative-Hypnotic Effects of Approved and Experimental Drugs in Rat. ACS Chem Biol 2017; 12:1593-1602. [PMID: 28414209 DOI: 10.1021/acschembio.7b00209] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
In this work, we describe the computational ("in silico") mode-of-action analysis of CNS-active drugs, which is taking both multiple simultaneous hypotheses as well as sets of protein targets for each mode-of-action into account, and which was followed by successful prospective in vitro and in vivo validation. Using sleep-related phenotypic readouts describing both efficacy and side effects for 491 compounds tested in rat, we defined an "optimal" (desirable) sleeping pattern. Compounds were subjected to in silico target prediction (which was experimentally confirmed for 21 out of 28 cases), followed by the utilization of decision trees for deriving polypharmacological bioactivity profiles. We demonstrated that predicted bioactivities improved classification performance compared to using only structural information. Moreover, DrugBank molecules were processed via the same pipeline, and compounds in many cases not annotated as sedative-hypnotic (alcaftadine, benzatropine, palonosetron, ecopipam, cyproheptadine, sertindole, and clopenthixol) were prospectively validated in vivo. Alcaftadine, ecopipam cyproheptadine, and clopenthixol were found to promote sleep as predicted, benzatropine showed only a small increase in NREM sleep, whereas sertindole promoted wakefulness. To our knowledge, the sedative-hypnotic effects of alcaftadine and ecopipam have not been previously discussed in the literature. The method described extends previous single-target, single-mode-of-action models and is applicable across disease areas.
Collapse
Affiliation(s)
- Georgios Drakakis
- Centre
for Molecular Informatics, Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - Keith A. Wafford
- Eli Lilly U.K., Erl Wood Manor, Windlesham, Surrey GU206PH, United Kingdom
| | | | - Michael J. Bodkin
- Eli Lilly U.K., Erl Wood Manor, Windlesham, Surrey GU206PH, United Kingdom
| | - David A. Evans
- Eli Lilly U.K., Erl Wood Manor, Windlesham, Surrey GU206PH, United Kingdom
| | - Andreas Bender
- Centre
for Molecular Informatics, Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| |
Collapse
|
9
|
Aly-Mahmoud M, Carlier P, Salam SA, Houari Selmani M, Moftah MZ, Esclapez M, Boussaoud D. Role of Anterior Cingulate Cortex in Instrumental Learning: Blockade of Dopamine D1 Receptors Suppresses Overt but Not Covert Learning. Front Behav Neurosci 2017; 11:82. [PMID: 28555096 PMCID: PMC5430040 DOI: 10.3389/fnbeh.2017.00082] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 04/19/2017] [Indexed: 11/25/2022] Open
Abstract
HIGHLIGHTSBlockade of dopamine D1 receptors in ACC suppressed instrumental learning when overt responding was required. Covert learning through observation was not impaired. After treatment with a dopamine antagonist, instrumental learning recovered but not the rat's pretreatment level of effort tolerance. ACC dopamine is not necessary for acquisition of task-relevant cues during learning, but regulates energy expenditure and effort based decision.
Dopamine activity in anterior cingulate cortex (ACC) is essential for various aspects of instrumental behavior, including learning and effort based decision making. To dissociate learning from physical effort, we studied both observational (covert) learning, and trial-and-error (overt) learning. If ACC dopamine activity is required for task acquisition, its blockade should impair both overt and covert learning. If dopamine is not required for task acquisition, but solely for regulating the willingness to expend effort for reward, i.e., effort tolerance, blockade should impair overt learning but spare covert learning. Rats learned to push a lever for food rewards either with or without prior observation of an expert conspecific performing the same task. Before daily testing sessions, the rats received bilateral ACC microinfusions of SCH23390, a dopamine D1 receptor antagonist, or saline-control infusions. We found that dopamine blockade suppressed overt responding selectively, leaving covert task acquisition through observational learning intact. In subsequent testing sessions without dopamine blockade, rats recovered their overt-learning capacity but not their pre-treatment level of effort tolerance. These results suggest that ACC dopamine is not required for the acquisition of conditioned behaviors and that apparent learning impairments could instead reflect a reduced level of willingness to expend effort due to cortical dopamine blockade.
Collapse
Affiliation(s)
| | - Pascal Carlier
- Aix Marseille Univ, INSERM, INS, Inst Neurosci SystMarseille, France
| | - Sherine A Salam
- Department of Zoology, Faculty of Science, Alexandria UniversityAlexandria, Egypt
| | - Mariam Houari Selmani
- Clinical Neurosciences Laboratory, Faculty of Medicine and Pharmacy, University Sidi Mohamed Ben AbdellahFez, Morocco
| | - Marie Z Moftah
- Department of Zoology, Faculty of Science, Alexandria UniversityAlexandria, Egypt
| | - Monique Esclapez
- Aix Marseille Univ, INSERM, INS, Inst Neurosci SystMarseille, France
| | - Driss Boussaoud
- Aix Marseille Univ, INSERM, INS, Inst Neurosci SystMarseille, France
| |
Collapse
|
10
|
Differential effect of orexin-1 and CRF-1 antagonism on stress circuits: a fMRI study in the rat with the pharmacological stressor Yohimbine. Neuropsychopharmacology 2013; 38:2120-30. [PMID: 23736277 PMCID: PMC3773661 DOI: 10.1038/npp.2013.109] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Revised: 04/22/2013] [Accepted: 05/03/2013] [Indexed: 12/23/2022]
Abstract
Translational approaches to study the neural substrates of stress and assess the mechanistic efficacy of novel anti-anxiety agents necessitate the use of stressors with a similar degree of saliency across species. The alpha-2 adrenoreceptor antagonist yohimbine represents an attractive experimental tool owing to its well-documented stress-inducing properties in humans and laboratory species. We investigated the neural substrates engaged by yohimbine in the rat brain by using functional magnetic resonance imaging and mapped their modulation by neurotransmitter systems involved in stress responses. Yohimbine elicited a composite pattern of brain activation, highlighting the recruitment of cortico-striato-thalamic regions and extra-hypothalamic stress neurocircuits. This effect was strongly attenuated by the α-2-adrenoceptor agonist medetomidine and by the dopamine (DA) D1 receptor antagonist SCH23390, thus revealing a primary contribution of both norepinephrine and DA on the neurofunctional cascade elicited by the drug. Pretreatment with the corticotrophin-releasing factor type-1 receptor (CRF1R) antagonist CP154,526 produced a region-dependent inhibition of yohimbine-induced activation in the amygdala, striatum, and cingulate cortex, while the orexin type-1 receptor (OX1R) antagonists GSK1059865 robustly inhibited the response in fronto-hippocampal regions as well as in several key components of the extended amygdala. CP154,526 and GSK1059865 did not prevent yohimbine-induced plasma corticosterone release, a finding that corroborates a central origin of the effects mapped. Our findings provide novel insight into the brain substrates and neurochemical mediators engaged by the stress-inducing agent yohimbine. The differential pattern of inhibition produced by CRF1R and OX1R antagonists suggests that these two neuropeptide systems can modulate the functional response to stress via distinct central neural pathways.
Collapse
|
11
|
Arsenault JT, Nelissen K, Jarraya B, Vanduffel W. Dopaminergic reward signals selectively decrease fMRI activity in primate visual cortex. Neuron 2013; 77:1174-86. [PMID: 23522051 DOI: 10.1016/j.neuron.2013.01.008] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/04/2013] [Indexed: 10/27/2022]
Abstract
Stimulus-reward coupling without attention can induce highly specific perceptual learning effects, suggesting that reward triggers selective plasticity within visual cortex. Additionally, dopamine-releasing events-temporally surrounding stimulus-reward associations-selectively enhance memory. These forms of plasticity may be evoked by selective modulation of stimulus representations during dopamine-inducing events. However, it remains to be shown whether dopaminergic signals can selectively modulate visual cortical activity. We measured fMRI activity in monkey visual cortex during reward-only trials apart from intermixed cue-reward trials. Reward without visual stimulation selectively decreased fMRI activity within the cue representations that had been paired with reward during other trials. Behavioral tests indicated that these same uncued reward trials strengthened cue-reward associations. Furthermore, such spatially-specific activity modulations depended on prediction error, as shown by manipulations of reward magnitude, cue-reward probability, cue-reward familiarity, and dopamine signaling. This cue-selective negative reward signal offers a mechanism for selectively gating sensory cortical plasticity.
Collapse
Affiliation(s)
- John T Arsenault
- Laboratory of Neuro and Psychophysiology, KU Leuven Medical School, Campus Gasthuisberg, 3000 Leuven, Belgium
| | | | | | | |
Collapse
|
12
|
Wright JM, Dobosiewicz MRS, Clarke PBS. The role of dopaminergic transmission through D1-like and D2-like receptors in amphetamine-induced rat ultrasonic vocalizations. Psychopharmacology (Berl) 2013; 225:853-68. [PMID: 23052567 DOI: 10.1007/s00213-012-2871-1] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Accepted: 09/02/2012] [Indexed: 12/23/2022]
Abstract
RATIONALE Systemic amphetamine (AMPH) administration increases the rate of 50-kHz ultrasonic vocalizations (USVs) in adult rats and preferentially enhances the 'trill' subtype; these effects of AMPH critically depend on noradrenergic transmission, but the possible contributions of dopamine are unclear. OBJECTIVE To assess the role of dopamine in 50-kHz USVs emitted drug-free and following systemic AMPH administration. METHODS Adult male Long-Evans rats pre-selected for high AMPH-induced calling rates were tested with AMPH (1 mg/kg, intraperitoneal (IP)) and saline following pretreatment with the following dopamine receptor antagonists: SCH 23390 (0.005-0.02 mg/kg, subcutaneous (SC)), SCH 39166 (0.03-0.3 mg/kg, SC), haloperidol (0.1, 0.2 mg/kg, IP), sulpiride (20-80 mg/kg, SC), raclopride (0.1-0.5 mg/kg, SC), clozapine (4 mg/kg, SC), risperidone (0.5 mg/kg, SC), and pimozide (1 mg/kg, IP). The dopamine and noradrenaline reuptake inhibitors (GBR 12909 and nisoxetine, respectively) were also tested, alone and in combination. RESULTS SCH 23390, SCH 39166, haloperidol, and raclopride dose-dependently inhibited vocalizations under AMPH and suppressed the proportion of trill calls. Sulpiride, however, had no discernable effect on call rate or profile, even at a high dose that reduced locomotor activity. Single doses of clozapine, risperidone, and pimozide all markedly decreased calling under saline and AMPH. Finally, GBR 12909 and nisoxetine failed to promote 50-kHz USVs detectably or alter the subtype profile, when tested alone or in combination. CONCLUSIONS The rate of 50-kHz USVs and the call subtype profile following systemic AMPH administration depends on dopaminergic neurotransmission through D1-like and D2-like receptors. However, inhibiting dopamine and/or noradrenaline reuptake appears insufficient to induce calling.
Collapse
Affiliation(s)
- Jennifer M Wright
- Department of Pharmacology and Therapeutics, McGill University, McIntyre Medical Building Rm. 1320 3655 Promenade Sir William Osler, Montreal, QC, H3G 1Y6, Canada
| | | | | |
Collapse
|
13
|
Abstract
Impulsivity is widely regarded as a multidimensional trait that encompasses two or more distinct patterns of behavior, and dopaminergic systems are implicated in the expression of impulsive behavior in both humans and animal subjects. Impulsive choice, or the tendency to choose rewards associated with relatively little or no delay, has been extensively studied in humans and animal subjects using delay-discounting tasks. Here, delay-discounting procedures were used to assess the effects of receptor-selective dopaminergic agonists, antagonists, and dopamine transporter ligands on choices of immediate versus delayed sucrose pellets. The effects of d-amphetamine, GBR 12909, apomorphine, SKF 81297, sumanirole, pramipexole, ABT-724, SCH 23390, L-741,626, PG01037, and L-745,870 were assessed in 24 Sprague-Dawley rats. The only drugs to affect impulsive choice selectively without altering undelayed choice were the D1-like antagonist, SCH 23390 (0.01 mg/kg), and the D4 partial agonist, ABT-724 (3.2 mg/kg), which both increased impulsive choice. The shared effects of these compounds may be explained by their localization within the prefrontal cortex on different groups of neurons. None of the selective agonists and antagonists tested reduced impulsive choice, so further research is needed to determine if direct dopaminergic agonists or antagonists may be therapeutically useful in the treatment of impulse-control disorders.
Collapse
|
14
|
Norman AB, Tabet MR, Norman MK, Fey BK, Tsibulsky VL, Millard RW. The affinity of D2-like dopamine receptor antagonists determines the time to maximal effect on cocaine self-administration. J Pharmacol Exp Ther 2011; 338:724-8. [PMID: 21606176 DOI: 10.1124/jpet.111.183244] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Differences in the time to maximal effect (T(max)) of a series of dopamine receptor antagonists on the self-administration of cocaine are not consistent with their lipophilicity (octanol-water partition coefficients at pH 7.4) and expected rapid entry into the brain after intravenous injection. It was hypothesized that the T(max) reflects the time required for maximal occupancy of receptors, which would occur as equilibrium was approached. If so, the T(max) should be related to the affinity for the relevant receptor population. This hypothesis was tested using a series of nine antagonists having a 2500-fold range of K(i) or K(d) values for D(2)-like dopamine receptors. Rats self-administered cocaine at regular intervals and then were injected intravenously with a dose of antagonist, and the self-administration of cocaine was continued for 6 to 10 h. The level of cocaine at the time of every self-administration (satiety threshold) was calculated throughout the session. The satiety threshold was stable before the injection of antagonist and then increased approximately 3-fold over the baseline value at doses of antagonists selected to produce this approximately equivalent maximal magnitude of effect (maximum increase in the equiactive cocaine concentration, satiety threshold; C(max)). Despite the similar C(max), the mean T(max) varied between 5 and 157 min across this series of antagonists. Furthermore, there was a strong and significant correlation between the in vivo T(max) values for each antagonist and the affinity for D(2)-like dopamine receptors measured in vitro. It is concluded that the cocaine self-administration paradigm offers a reliable and predictive bioassay for measuring the affinity of a competitive antagonist for D(2)-like dopamine receptors.
Collapse
Affiliation(s)
- Andrew B Norman
- Department of Psychiatry and Behavioral Neuroscience, College of Medicine, University of Cincinnati, 2170 E. Galbraith Rd., Cincinnati, OH 45237-0506, USA.
| | | | | | | | | | | |
Collapse
|
15
|
Nakagome K, Imamura M, Okada H, Kawahata K, Inoue T, Hashimoto K, Harada H, Higashi T, Takagi R, Nakano K, Hagiwara K, Kanazawa M, Dohi M, Nagata M, Matsushita S. Dopamine D1-like receptor antagonist attenuates Th17-mediated immune response and ovalbumin antigen-induced neutrophilic airway inflammation. THE JOURNAL OF IMMUNOLOGY 2011; 186:5975-82. [PMID: 21471450 DOI: 10.4049/jimmunol.1001274] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Allergic airway inflammation is generally considered a Th2-type immune response. Recent studies, however, demonstrated that Th17-type immune responses also play important roles in this process, especially in the pathogenesis of neutrophilic airway inflammation, a hallmark of severe asthma. We previously reported that dendritic cells release dopamine to naive CD4(+) T cells in Ag-specific cell-cell interaction, in turn inducing Th17 differentiation through dopamine D1-like receptor (D1-like-R). D1-like-R antagonist attenuates Th17-mediated diseases such as experimental autoimmune encephalomyelitis and autoimmune diabetes. However, the effect of antagonizing D1-like-R on Th17-mediated airway inflammation has yet to be studied. In this study, we examined whether D1-like-R antagonist suppresses OVA-induced neutrophilic airway inflammation in OVA TCR-transgenic DO11.10 mice and then elucidated the mechanism of action. DO11.10 mice were nebulized with OVA or PBS, and some mice received D1-like-R antagonist orally before OVA nebulization. D1-like-R antagonist significantly suppressed OVA-induced neutrophilic airway inflammation in DO11.10 mice. It also inhibited the production of IL-17 and infiltration of Th17 cells in the lung. Further, D1-like-R antagonist suppressed the production of IL-23 by lung CD11c(+) APCs. In contrast, D1-like-R antagonist did not increase Foxp3(+) regulatory T cells in the lung. D1-like-R antagonist neither suppressed nonspecific LPS-induced neutrophilic airway inflammation nor OVA-induced eosinophilic airway inflammation. These results indicate that D1-like-R antagonist could suppress Th17-mediated neutrophilic airway inflammation, raising the possibility that antagonizing D1-like-R serves as a promising new strategy for treating neutrophil-dominant severe asthma.
Collapse
Affiliation(s)
- Kazuyuki Nakagome
- Department of Respiratory Medicine, Saitama Medical University, Saitama 350-0495, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Norman AB, Tabet MR, Norman MK, Tsibulsky VL. Using the self-administration of apomorphine and cocaine to measure the pharmacodynamic potencies and pharmacokinetics of competitive dopamine receptor antagonists. J Neurosci Methods 2010; 194:252-8. [PMID: 20974176 DOI: 10.1016/j.jneumeth.2010.10.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2009] [Revised: 09/30/2010] [Accepted: 10/18/2010] [Indexed: 11/20/2022]
Abstract
Competitive dopamine receptor antagonists accelerate psychomotor stimulant self-administration. According to pharmacological theory of competitive antagonism antagonists raise the equiactive agonist concentration. In the self-administration paradigm this is assumed to be the satiety threshold or C(min). The magnitude of the proportional increase in satiety threshold (agonist concentration ratio) as a function of antagonist dose should reflect the antagonist pharmacodynamic potency. The time course of this effect should reflect the rate of change of antagonist occupancy of receptors and, therefore, antagonist concentration, i.e. pharmacokinetics. Rats self-administered apomorphine or cocaine at a stable rate and were then injected i.v. with one of four competitive D₁-like or D₂-like dopamine receptor antagonists and the session continued. The agonist concentrations at the time of each self-administration (satiety thresholds) were calculated during the session. The antagonists accelerated self-administration of both agonists with a concomitant increase in the calculated satiety thresholds. The maximum agonist concentration ratio was proportional to the dose of antagonist. The time courses of the changes in agonist concentration ratio were independent of the agonist and of the dose of antagonist. Schild analysis of the maximum agonist concentration ratio as a function of the antagonist dose allowed apparent pA₂ (or K(dose)) to be measured. Antagonist K(dose) values should provide a quantitative basis for receptor identification in behavioral pharmacology. The assay system may also measure the pharmacokinetics of antagonist elimination from the brain. Agonist self-administration represents a sensitive in vivo pharmacological assay system that provides information useful for pharmacokinetic/pharmacodynamic modeling of antagonist effects.
Collapse
Affiliation(s)
- Andrew B Norman
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, College of Medicine, 231 Albert Sabin Way, Cincinnati, OH 45267, USA.
| | | | | | | |
Collapse
|
17
|
Norman AB, Norman MK, Tabet MR, Tsibulsky VL, Pesce AJ. Competitive dopamine receptor antagonists increase the equiactive cocaine concentration during self-administration. Synapse 2010; 65:404-11. [PMID: 20812328 DOI: 10.1002/syn.20858] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2010] [Accepted: 08/16/2010] [Indexed: 11/10/2022]
Abstract
Competitive dopamine receptor antagonists increase the rate of cocaine self-administration. As the rate of self-administration at a particular unit dose is determined by the satiety threshold and the elimination half-life (t(½)) of cocaine, we investigated whether dopamine receptor antagonists altered these parameters in rats. The plasma cocaine concentration at the time of each self-administration was constant during a session demonstrating that this satiety threshold concentration represents an equiactive cocaine concentration. The plasma cocaine concentration at the time of self-administration was increased by SCH23390, consistent with pharmacological theory. In rats trained to reliably self-administer cocaine, SCH23390 had no effect on the plasma steady-state cocaine concentration produced by constant infusions of cocaine. Therefore, this antagonist had no effect on cocaine t(½) at a dose that accelerated cocaine self-administration. A constant cocaine infusion at a rate that maintained steady state concentrations above the satiety threshold stopped self-administration. SCH23390, or the D₂ dopamine receptor antagonist (-)eticlopride, reinstated self-administration in the presence of the constant cocaine infusion. This is consistent with SCH23390 and eticlopride raising the satiety threshold above the steady state level produced by the constant cocaine infusion. It is concluded that the antagonist-induced acceleration of cocaine self-administration is the result of a pharmacokinetic/pharmacodynamic interaction whereby the rate of cocaine elimination is faster at the higher concentrations, as dictated by first-order kinetics, so that cocaine levels decline more rapidly to the elevated satiety threshold. This results in the decreased interinjection intervals.
Collapse
Affiliation(s)
- Andrew B Norman
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267-0583, USA.
| | | | | | | | | |
Collapse
|
18
|
Gozzi A, Crestan V, Turrini G, Clemens M, Bifone A. Antagonism at serotonin 5-HT(2A) receptors modulates functional activity of frontohippocampal circuit. Psychopharmacology (Berl) 2010; 209:37-50. [PMID: 20111859 DOI: 10.1007/s00213-009-1772-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2009] [Accepted: 12/20/2009] [Indexed: 12/22/2022]
Abstract
RATIONALE Several second-generation antipsychotics are characterised by a significant antagonistic effect at serotonin 5-HT(2A) receptors (5-HT(2A)R), a feature that has been associated with lower incidence of extra-pyramidal symptoms and a putative amelioration of positive and negative symptoms experienced by schizophrenic patients. However, the neurofunctional substrate of 5-HT(2A) antagonism and its exact contribution to the complex pharmacological profile of these drugs remain to be elucidated. OBJECTIVES Here, we used pharmacological magnetic resonance imaging to map the modulatory effects of the selective 5-HT(2A)R antagonist Ml00907 on the spatiotemporal patterns of brain activity elicited by acute phencyclidine (PCP) challenge in the rat. PCP is a non-competitive NMDA receptor antagonist that induces dysregulation of corticolimbic glutamatergic neurotransmission and produces cognitive impairment and psychotic-like symptoms reminiscent of those observed in schizophrenia. RESULTS Pre-administration of M100907 produced focal and region-dependent attenuation of PCP-induced response in frontoseptohippocampal areas. As early studies highlighted a permissive role of 5-HT(2A)R on frontal dopamine release, the role of post-synaptic dopamine D(1) receptors on PCP-induced response was examined by using the potent antagonist SCH23390. Interestingly, SCH23390 did not affect PCP's response in any of the regions examined. This finding rules out a significant contribution of dopamine in the functional changes mapped and, indirectly, the inhibitory effect of M100907, in favour of a glutamatergic origin. CONCLUSIONS Our data expand recent evidence suggesting a key role of 5-HT(2A)R in modulating glutamate-mediated cognitive performance in the prefrontal cortex and highlight the whole frontoseptohippocampal circuit as a key functional substrate of 5-HT(2A)R antagonism in normal and disease states.
Collapse
Affiliation(s)
- Alessandro Gozzi
- Biology, Neurosciences CEDD, GlaxoSmithKline Medicines Research Centre, Verona, Italy
| | | | | | | | | |
Collapse
|
19
|
Worden LT, Shahriari M, Farrar AM, Sink KS, Hockemeyer J, Müller CE, Salamone JD. The adenosine A2A antagonist MSX-3 reverses the effort-related effects of dopamine blockade: differential interaction with D1 and D2 family antagonists. Psychopharmacology (Berl) 2009; 203:489-99. [PMID: 19048234 PMCID: PMC2875246 DOI: 10.1007/s00213-008-1396-0] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2008] [Accepted: 10/21/2008] [Indexed: 11/24/2022]
Abstract
RATIONALE Brain dopamine (DA) participates in the modulation of instrumental behavior, including aspects of behavioral activation and effort-related choice behavior. Rats with impaired DA transmission reallocate their behavior away from food-seeking behaviors that have high response requirements, and instead select less effortful alternatives. Although accumbens DA is considered a critical component of the brain circuitry regulating effort-related choice behavior, emerging evidence demonstrates a role for adenosine A(2A) receptors. OBJECTIVE Adenosine A(2A) receptor antagonism has been shown to reverse the effects of DA antagonism. The present experiments were conducted to determine if this effect was dependent upon the subtype of DA receptor that was antagonized to produce the changes in effort-related choice. MATERIALS AND METHODS The adenosine A(2A) receptor antagonist MSX-3 (0.5-2.0 mg/kg IP) was assessed for its ability to reverse the effects of the D1 family antagonist SCH39166 (ecopipam; 0.2 mg/kg IP) and the D2 family antagonist eticlopride (0.08 mg/kg IP), using a concurrent lever pressing/chow feeding procedure. RESULTS MSX-3 produced a substantial dose-related reversal of the effects of eticlopride on lever pressing and chow intake. At the highest dose of MSX-3, there was a complete reversal of the effects of eticlopride on lever pressing. In contrast, MSX-3 produced only a minimal attenuation of the effects of SCH39166, as measured by regression and effect size analyses. CONCLUSIONS The greater ability of MSX-3 to reverse the effects of D2 vs. D1 blockade may be related to the colocalization of D2 and adenosine A(2A) receptors on the same population of striatal neurons.
Collapse
Affiliation(s)
- Lila T. Worden
- Division of Behavioral Neuroscience, Department of Psychology, University of Connecticut, Storrs, CT 06269-1020, USA
| | - Mona Shahriari
- Division of Behavioral Neuroscience, Department of Psychology, University of Connecticut, Storrs, CT 06269-1020, USA
| | - Andrew M. Farrar
- Division of Behavioral Neuroscience, Department of Psychology, University of Connecticut, Storrs, CT 06269-1020, USA
| | - Kelly S. Sink
- Division of Behavioral Neuroscience, Department of Psychology, University of Connecticut, Storrs, CT 06269-1020, USA
| | - Jörg Hockemeyer
- Pharmazeutisches Institut, Pharmazeutische Chemie I, Universität Bonn, Bonn, Germany
| | - Christa E. Müller
- Pharmazeutisches Institut, Pharmazeutische Chemie I, Universität Bonn, Bonn, Germany
| | - John D. Salamone
- Division of Behavioral Neuroscience, Department of Psychology, University of Connecticut, Storrs, CT 06269-1020, USA
| |
Collapse
|
20
|
Zhou Y, Spangler R, Yuferov VP, Schlussmann SD, Ho A, Kreek MJ. Effects of selective D1- or D2-like dopamine receptor antagonists with acute "binge" pattern cocaine on corticotropin-releasing hormone and proopiomelanocortin mRNA levels in the hypothalamus. ACTA ACUST UNITED AC 2005; 130:61-7. [PMID: 15519677 DOI: 10.1016/j.molbrainres.2004.07.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/13/2004] [Indexed: 11/30/2022]
Abstract
We have previously demonstrated that there are stimulatory effects of acute (1 day) "binge" cocaine on corticotropin-releasing hormone (CRH) gene expression in the rat hypothalamus and on the stress responsive hypothalamic-pituitary-adrenal (HPA) activity. The first aim of the present study was to investigate the possible role of dopamine (DA) D1- or D2-like receptors (D1R or D2R) in modulating these acute effects. Administration of acute "binge" cocaine (3x15 mg/kg, i.p.) was preceded by injections of either the selective D1R antagonist (SCH23390, 2 mg/kg) or D2R antagonist (sulpiride, 50 mg/kg). The D1R or D2R blockade by SCH23390 or sulpiride, respectively, did not alter the mRNA levels of CRH in the hypothalamus, CRH-R1 or proopiomelanocortin (POMC) in the anterior pituitary. However, the acute "binge" cocaine-induced increase in hypothalamic CRH mRNA levels was not found in the rats that received either D1R or D2R antagonist pretreatment. In the anterior pituitary, acute "binge" cocaine or its combinations with either DA antagonist did not alter CRH-R1 receptor or POMC mRNA levels. Both the D1R and D2R antagonists attenuated the elevation of plasma corticosterone levels induced by acute "binge" cocaine. These results suggest that both D1R and D2R mediate acute cocaine's stimulatory effect on HPA axis at the hypothalamic CRH level. Neurobiological evidence has demonstrated functional interactions between dopaminergic and opioidergic systems that regulate preproenkephalin and preprodynorphin gene expression in the striatum. The second aim of our study was to investigate the roles that D1R or D2R could play in regulation of POMC mRNA levels in the hypothalamus in response to acute "binge" cocaine. The D2R blockade by sulpiride increased POMC mRNA levels in the hypothalamus, indicating that D2R exerts a tonic inhibitory effect on hypothalamic POMC gene expression. The POMC mRNA increases induced by the D2R blockade were attenuated by acute "binge" cocaine. Neither the D2R blockade nor acute "binge" cocaine altered POMC mRNA levels in the amygdala, anterior pituitary or neurointermediate lobe of the pituitary. In contrast to the D2R, the D1R blockade by SCH23390, acute "binge" cocaine or their combination had no effect on hypothalamic POMC mRNA levels. These results support a specific role for D2R in acute cocaine's effects on hypothalamic POMC gene expression.
Collapse
Affiliation(s)
- Yan Zhou
- Laboratory of the Biology of Addictive Diseases, Box 171, The Rockefeller University, New York, NY 10021, USA.
| | | | | | | | | | | |
Collapse
|
21
|
Zhou Y, Spangler R, Ho A, Jeanne Kreek M. Hypothalamic CRH mRNA levels are differentially modulated by repeated 'binge' cocaine with or without D(1) dopamine receptor blockade. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 2001; 94:112-8. [PMID: 11597771 DOI: 10.1016/s0169-328x(01)00223-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
We previously found that there was a rapid stimulatory effect of acute (1 day) 'binge' cocaine on CRH mRNA levels in the rat hypothalamus. In contrast, after 3 days of 'binge' cocaine, there was a modest decrease (12%) in hypothalamic CRH mRNA levels, which after 14 days of 'binge' cocaine was greater (32%) and significantly lower than control values. Also, our previous studies found an elevation of CRH mRNA in the frontal cortex after 3 days of 'binge' cocaine. The present study was designed to investigate the possible role of dopamine receptors in modulating these effects. Administration of 3 days of 'binge' cocaine (3 x 15 mg/kg, i.p.) was preceded by daily injections of either D(1) (SCH23390, 2 mg/kg) or D(2) (sulpiride, 50 mg/kg) dopamine receptor antagonist. Neither SCH23390 nor sulpiride had an effect on basal CRH mRNA levels in the hypothalamus, frontal cortex or amygdala. Small decreases (10-13%) in hypothalamic CRH mRNA levels were found again to be induced by 3 days of repeated 'binge' cocaine. However, this modest decrease was not found in the rats that received D(1) antagonist SCH23390 pretreatment. Pretreatment with D(2) antagonist sulpiride had no effect on this decrease. These findings suggest that the inhibitory effect of repeated 'binge' cocaine on the hypothalamic CRH mRNA expression is absent when there is D(1), but not D(2), dopamine receptor blockade. In the frontal cortex, pretreatment with either SCH23390 or sulpiride did not alter the increases in the CRH mRNA levels induced by repeated 'binge' cocaine. The results suggest that the cocaine-induced modulation of hypothalamic CRH mRNA expression is secondary to changes in the activity of specific components of dopaminergic systems.
Collapse
Affiliation(s)
- Y Zhou
- Laboratory of the Biology of Addictive Diseases, The Rockefeller University, New York, NY 10021, USA.
| | | | | | | |
Collapse
|
22
|
Dopamine D1 and NMDA receptors mediate potentiation of basolateral amygdala-evoked firing of nucleus accumbens neurons. J Neurosci 2001. [PMID: 11487660 DOI: 10.1523/jneurosci.21-16-06370.2001] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Interactions between the basolateral amygdala (BLA) and the nucleus accumbens (NAc) mediate reward-related processes that are modulated by mesoaccumbens dopamine (DA) transmission. The present in vivo electrophysiological study assessed: (1) changes in the firing probability of submaximal BLA-evoked single neuronal firing activity in the NAc after tetanic stimulation of the BLA, and (2) the functional roles of DA and NMDA receptors in these processes. Tetanic stimulation of the BLA potentiated BLA-evoked firing activity of NAc neurons for a short duration ( approximately 25 min). This short-term potentiation was associated with an increase in DA oxidation currents that was monitored with chronoamperometry. Systemic or iontophoretic application before BLA tetanus of the D(1) receptor antagonist SCH23390, but not the D(2) receptor antagonist sulpiride, abolished the potentiation of BLA-evoked NAc activity, whereas administration of SCH23390 3 min after tetanus had no effect. However, systemic administration of the NMDA antagonist 3-(2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (CPP), either before or after BLA tetanus, abolished the potentiation of BLA-evoked firing of NAc neurons. These data suggest that higher-frequency activity in BLA efferents can autoregulate their excitatory influence over neural activity of NAc neurons by facilitating the release of DA and activating both DA D(1) and NMDA receptors. This may represent a cellular mechanism that facilitates approach behaviors directed toward reward-related stimuli that are mediated by BLA-NAc circuitries.
Collapse
|
23
|
Coirini H, Källström L, Wiesel FA, Johnson AE. Modulation of basal ganglia neurotransmission by the classical antipsychotic fluphenazine is due in part to the blockade of dopamine D1-receptors. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 1997; 49:197-210. [PMID: 9387879 DOI: 10.1016/s0169-328x(97)00144-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Classical antipsychotics, such as fluphenazine, influence neurotransmission by blocking both dopamine D1- and D2-receptors which in turn results in widespread adaptive changes in the neurochemistry of the basal ganglia. The purpose of the present study was to determine the role of D1-receptors in mediating some of these neurochemical events, including changes in D1- and D2-receptor binding, and the expression of preproenkephalin and glutamic acid decarboxylase mRNAs. For these experiments, rats were given a depot injection of fluphenazine decanoate or injected twice daily for 21 days with the D1-receptor antagonist SCH-23390. An additional group received both fluphenazine and SCH-23390 and controls were given saline. Fluphenazine administration decreased D2-receptor binding throughout the basal ganglia while SCH-23390 was without effect. In contrast to the uniform reduction in D2-receptor binding, fluphenazine altered D1-receptor binding in a region-dependent manner. Region-dependent changes were also observed in animals given SCH-23390 which increased binding in the entopeduncular nucleus and posterior caudate-putamen without affecting other brain regions. Both fluphenazine and SCH-23390 significantly enhanced preproenkephalin and glutamic acid decarboxylase (GAD) mRNA expression in the anterior striatum. Fluphenazine also increased GAD mRNA levels in the entopeduncular nucleus. Together, these results indicate that the attenuation of D1-receptor-mediated neurotransmission modulates a number of clinically relevant neurochemical processes in the basal ganglia.
Collapse
Affiliation(s)
- H Coirini
- Instituto de Biología y Medicina Experimental, and Department of Human Biochemistry, School of Medicine, University of Buenos Aires, Argentina
| | | | | | | |
Collapse
|
24
|
Awasaki Y, Nishida N, Sasaki S, Sato S. Dopamine D(1) antagonist SCH23390 attenuates self-administration of both cocaine and fentanyl in rats. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 1997; 3:115-122. [PMID: 21781768 DOI: 10.1016/s1382-6689(97)00147-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/1996] [Revised: 12/12/1996] [Accepted: 12/23/1996] [Indexed: 05/31/2023]
Abstract
To investigate the role of dopamine D(1) receptors in the reinforcing effects of cocaine and fentanyl, the effect of the D(1) antagonist SCH23390 on intravenous self-administration of these drugs was investigated in rats using a progressive ratio (PR) reinforcement schedule, during which the rats received the first three injections under an FR1 schedule. Then the number of lever presses required to deliver an injection (lever press ratio) increased by three after every three further injections. The last lever press ratio completed by each rat during each 6 h session was designated the breaking point. Breaking point values increased dose-dependently during both cocaine (0.125-1.00 mg/kg per injection) and fentanyl (0.25-2.00 μg/kg per injection) self-administration. Pretreatment with SCH23390 (0.01 mg/kg, s.c.) decreased breaking point values for both cocaine and fentanyl, reflecting a decrease in the reinforcing efficacy of the drugs. To determine whether the effect of SCH23390 was due to general suppression of the lever pressing response, the effect of SCH23390 (0.01 mg/kg, s.c.) on the performance of rats maintained by water-reinforcement was examined. SCH23390 suppressed performance only transiently, therefore general suppression appears to have little or no effect on the breaking point. These results suggest that dopamine D(1) receptors are involved in mediating the reinforcing effects of both the psychostimulant cocaine and the opiate fentanyl.
Collapse
Affiliation(s)
- Y Awasaki
- Drug Safety Research Laboratories, Takeda Chemical Industries. Ltd., 2-17-85 Jusohonmachi Yodogawaku, Osaka 532, Japan
| | | | | | | |
Collapse
|
25
|
Fdez Espejo E, Gil E. Single restraint stress sensitizes acute chewing movements induced by haloperidol, but not if the 5-HT1A agonist 8-OH-DPAT is given prior to stress. Brain Res 1997; 755:351-5. [PMID: 9175906 DOI: 10.1016/s0006-8993(97)00242-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The objective of this study was two-fold: (i) to analyze behavioral sensitization to haloperidol 2 weeks after single restraint stress, and (ii) to establish the effects of 8-OH-DPAT treatment prior to stress on sensitized behavioral responses. Overall behavior was analyzed and not only catalepsy, but also sedation (immobility), grooming, exploration and vacuous chewing movements were evaluated. Results indicated that single restraint stress induced a long-lasting sensitization of acute vacuous chewing movements induced by haloperidol (0.25, 0.5 mg/kg i.p.). Interestingly, this behavioral sensitization was prevented by 8-OH-DPAT (0.35 mg/kg s.c.) prior to stress. Finally, haloperidol-induced sedation was not disrupted by either restraint stress or 8-OH-DPAT treatment.
Collapse
Affiliation(s)
- E Fdez Espejo
- Depto. de Fisiología Medica y Biofísica, Universidad de Sevilla, Seville, Spain.
| | | |
Collapse
|
26
|
Lin CC, Kim HK, Parker D. Sensitive high-performance liquid chromatographic method for the determination of a benzonaphthazepine antipsychotic agent, SCH 39166, and its active metabolite, SCH 40853, in human plasma and its cross-validation with a gas chromatographic method. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL APPLICATIONS 1996; 682:309-13. [PMID: 8844424 DOI: 10.1016/0378-4347(96)00089-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A sensitive high-performance liquid chromatographic (HPLC) method was developed for the determination of a benzonaphthazepine antipsychotic agent, SCH 39166, and its active metabolite, SCH 40853. The HPLC method required a single-step organic extraction at alkali pH followed by HPLC analysis utilizing a CN column with UV detection at 205 nm. The limit of quantitation was 1 ng/ml for SCH 39166 and 0.5 ng/ml for SCH 40853. The HPLC method was cross-validated with a previously reported GC method by the analysis of 73 plasma samples spiked with various concentrations of SCH 39166 and SCH 40853. The correlation coefficient was 0.9969 for SCH 39166 and 0.9984 for SCH 40853. Both GC and HPLC methods were used for the determination of plasma concentrations and yielded similar pharmacokinetic parameters for SCH 39166 and SCH 40853 in man following oral administration of SCH 39166 (100 mg).
Collapse
Affiliation(s)
- C C Lin
- Department of Drug Metabolism, Schering-Plough Research Institute, Kenilworth, NJ 07033, USA
| | | | | |
Collapse
|
27
|
Hyde TM, Egan MF, Wing LL, Wyatt RJ, Weinberger DR, Kleinman JE. Persistent catalepsy associated with severe dyskinesias in rats treated with chronic injections of haloperidol decanoate. Psychopharmacology (Berl) 1995; 118:142-9. [PMID: 7617800 DOI: 10.1007/bf02245832] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Patients who develop persistent parkinsonism while on chronic neuroleptic therapy may be predisposed towards the development of tardive dyskinesia (TD). We investigated this issue in an animal model of TD by examining the association between catalepsy and the syndrome of neuroleptic-induced vacuous chewing movements (VCMs). VCMs were measured every 3 weeks for 33 weeks while rats received injections of haloperidol decanoate. Catalepsy was measured after the second through the seventh injections of the depot neuroleptic. There were no correlations between the severity of catalepsy scores after the second or third injections of haloperidol and the severity of the overall VCM syndrome. However, the severity of the catalepsy score following the third through seventh injections of haloperidol strongly correlated with the concurrent number of VCMs. Persistent high catalepsy scores across the six catalepsy rating sessions were strongly associated with the development of persistent severe VCMs. These findings suggest that, to the extent that persistent parkinsonian signs in humans are associated with a propensity towards the development of TD, the VCM syndrome in rats is at least a partially faithful animal model of this relationship.
Collapse
Affiliation(s)
- T M Hyde
- Clinical Brain Disorders Branch, National Institute of Mental Health, St. Elizabeths Hospital, Washington, DC 20032, USA
| | | | | | | | | | | |
Collapse
|
28
|
Knable MB, Hyde TM, Egan MF, Tosayali M, Wyatt RJ, Kleinman JE. Quantitative autoradiography of striatal dopamine D1, D2 and re-uptake sites in rats with vacuous chewing movements. Brain Res 1994; 646:217-22. [PMID: 8069667 DOI: 10.1016/0006-8993(94)90081-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Rats treated with haloperidol that developed vacuous chewing movements (VCM), a possible animal model of tardive dyskinesia, were studied with quantitative autoradiography for dopamine type-1 (D1) and type-2 (D2) receptors as well as dopamine re-uptake sites. Haloperidol increased striatal D2 receptors, but did not affect D1 receptors or the dopamine re-uptake site. D2 receptor increases occurred in rats with and without VCMs. In so far as VCM is a model for tardive dyskinesia, haloperidol induced increases in striatal D2 receptors do not appear to be etiologic for these abnormal movements.
Collapse
Affiliation(s)
- M B Knable
- Clinical Brain Disorders Branch, National Institute of Mental Health, St. Elizabeths Hospital, Washington, DC 20032
| | | | | | | | | | | |
Collapse
|
29
|
Terry P, Katz JL. A comparison of the effects of the D1 receptor antagonists SCH 23390 and SCH 39166 on suppression of feeding behavior by the D1 agonist SKF38393. Psychopharmacology (Berl) 1994; 113:328-33. [PMID: 7862841 DOI: 10.1007/bf02245205] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The hypophagic effect of the D1 receptor agonist SKF 38393 is not dose-dependently antagonized by the D1 antagonist SCH 23390. Moreover, the receptor specificity of this interaction remains in question, since SCH 23390 has significant activity at both 5-HT2 and 5-HT1C receptors, and SKF 38393 also interacts with 5-HT1C receptors. To determine the relative significance of these actions, a comparison was made between the anorectic effects in rats of SCH 23390 (0.1-1.0 mg/kg) and the benzonaphthazepine SCH 39166 (0.1-3.0 mg/kg), a D1 antagonist with negligible affinity for 5-HT sites. Both compounds inhibited food-intake dose-dependently, with SCH 23390 being approximately twice as potent as SCH 39166. Behaviorally inactive and active doses of both antagonists were tested in combination with the D1 agonist SKF 38393 (10-56 mg/kg). Neither antagonist was able to produce more than a marginal attenuation of the agonist-induced hypophagia. This demonstrates that previous failures to reverse the behavioral actions of SKF 38393 by SCH 23390 were not due to specific actions of this particular antagonist. Finally, like SCH 23390, SCH 39166 (0.3 mg/kg) was able to attenuate fully the anorectic effects of the D1 agonist SKF 82958 (1.0 and 3.0 mg/kg), demonstrating that neither compound is intrinsically unable to block D1 receptor-mediated hypophagia. The results demonstrate the generality of the D1 antagonist-mediated effect on feeding and call into question the use of SKF 38393 as a D1 agonist in studies of feeding, and perhaps in other contexts as well.
Collapse
Affiliation(s)
- P Terry
- Psychobiology Section, NIDA Addiction Research Center, Baltimore, MD 21224
| | | |
Collapse
|
30
|
Tedford CE, Coffin VL, Ruperto V, Cohen M, McQuade RD, Johnson R, Kim HK, Lin CC. Determination of plasma and brain concentrations of SCH 39166 and their correlation to conditioned avoidance behavior in rats. Psychopharmacology (Berl) 1993; 113:199-204. [PMID: 7855181 DOI: 10.1007/bf02245697] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Plasma and brain concentrations of the dopamine D1 receptor antagonist, SCH 39166, were measured and compared to behavioral activity in the conditioned avoidance response paradigm (CAR). SCH 39166 was administered at two behaviorally active doses (1 mg/kg, SC and 10 mg/kg, PO) and the time course for CAR activity was compared with the plasma and brain concentrations of unconjugated SCH 39166. Conjugation and N-demethylation of SCH 39166 after oral administration were also determined and first pass metabolism examined. Results from these studies demonstrated a similar time-dependent disappearance of unconjugated SCH 39166 from both the plasma and brain, independent of route of administration. Brain concentrations of SCH 39166 were approximately 5-fold higher than corresponding plasma concentrations, regardless of route. However, plasma and brain concentrations of unconjugated SCH 39166 were higher after SC administration of 1.0 mg/kg, than after PO administration of 10 mg/kg, suggesting a substantial first pass metabolism of SCH 39166. In addition, total (conjugated and unconjugated) plasma concentrations of SCH 39166 were at least 10-fold higher than unconjugated concentrations of SCH 39166 after PO administration of 10 mg/kg, demonstrating that a high proportion of drug was conjugated. Metabolism to the N-desmethyl analog, SCH 40853, was observed after PO administration of 10 mg/kg SCH 39166 and a high proportion of conjugation of the desmethyl analog was also seen. Finally, plasma concentrations of unconjugated SCH 39166 exhibited a high positive correlation (r = 0.934, P < 0.001) with brain concentrations of unconjugated SCH 39166.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- C E Tedford
- Schering-Plough Research Institute, Kenilworth, NJ 07033-0539
| | | | | | | | | | | | | | | |
Collapse
|