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Dairaghi L, Constantin S, Oh A, Shostak D, Wray S. The Dopamine D4 Receptor Regulates Gonadotropin-Releasing Hormone Neuron Excitability in Male Mice. eNeuro 2022; 9:ENEURO.0461-21.2022. [PMID: 35165199 PMCID: PMC8896547 DOI: 10.1523/eneuro.0461-21.2022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 01/26/2022] [Accepted: 02/02/2022] [Indexed: 12/30/2022] Open
Abstract
Gonadotropin-releasing hormone (GnRH)-secreting neurons control fertility. The release of GnRH peptide regulates the synthesis and release of both luteinizing hormone (LH) and Follicle stimulation hormone (FSH) from the anterior pituitary. While it is known that dopamine regulates GnRH neurons, the specific dopamine receptor subtype(s) involved remain unclear. Previous studies in adult rodents have reported juxtaposition of fibers containing tyrosine hydroxylase (TH), a marker of catecholaminergic cells, onto GnRH neurons and that exogenous dopamine inhibits GnRH neurons postsynaptically through dopamine D1-like and/or D2-like receptors. Our microarray data from GnRH neurons revealed a high level of Drd4 transcripts [i.e., dopamine D4 receptor (D4R)]. Single-cell RT-PCR and immunocytochemistry confirmed GnRH cells express the Drd4 transcript and protein, respectively. Calcium imaging identified changes in GnRH neuronal activity during application of subtype-specific dopamine receptor agonists and antagonists when GABAergic and glutamatergic transmission was blocked. Dopamine, dopamine with D1/5R-specific or D2/3R-specific antagonists or D4R-specific agonists decreased the frequency of calcium oscillations. In contrast, D1/5R-specific agonists increased the frequency of calcium oscillations. The D4R-mediated inhibition was dependent on Gαi/o protein coupling, while the D1/5R-mediated excitation required Gαs protein coupling. Together, these results indicate that D4R plays an important role in the dopaminergic inhibition of GnRH neurons.
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Affiliation(s)
| | | | - Andrew Oh
- Cellular and Developmental Neurobiology Section, National Institute of Neurological Disorders and Stroke/National Institutes of Health, Bethesda, MD 20892
| | - David Shostak
- Cellular and Developmental Neurobiology Section, National Institute of Neurological Disorders and Stroke/National Institutes of Health, Bethesda, MD 20892
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Conde Rojas I, Acosta-García J, Caballero-Florán RN, Jijón-Lorenzo R, Recillas-Morales S, Avalos-Fuentes JA, Paz-Bermúdez F, Leyva-Gómez G, Cortés H, Florán B. Dopamine D4 receptor modulates inhibitory transmission in pallido-pallidal terminals and regulates motor behavior. Eur J Neurosci 2020; 52:4563-4585. [PMID: 33098606 DOI: 10.1111/ejn.15020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 10/14/2020] [Accepted: 10/16/2020] [Indexed: 12/28/2022]
Abstract
Two major groups of terminals release GABA within the Globus pallidus; one group is constituted by projections from striatal neurons, while endings of the intranuclear collaterals form the other one. Each neurons' population expresses different subtypes of dopamine D2-like receptors: D2 R subtype is expressed by encephalin-positive MSNs, while pallidal neurons express the D4 R subtype. The D2 R modulates the firing rate of striatal neurons and GABA release at their projection areas, while the D4 R regulates Globus pallidus neurons excitability and GABA release at their projection areas. However, it is unknown if these receptors control GABA release at pallido-pallidal collaterals and regulate motor behavior. Here, we present neurochemical evidence of protein content and binding of D4 R in pallidal synaptosomes, control of [3 H] GABA release in pallidal slices of rat, electrophysiological evidence of the presence of D4 R on pallidal recurrent collaterals in mouse slices, and turning behavior induced by D4 R antagonist microinjected in amphetamine challenged rats. As in projection areas of pallidal neurons, GABAergic transmission in pallido-pallidal recurrent synapses is under modulation of D4 R, while the D2 R subtype, as known, modulates striato-pallidal projections. Also, as in projection areas, D4 R contributes to control the motor activity differently than D2 R. This study could help to understand the organization of intra-pallidal circuitry.
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Affiliation(s)
- Israel Conde Rojas
- Departamento de Fisiología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, México, México
| | | | | | - Rafael Jijón-Lorenzo
- Departamento de Fisiología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, México, México
| | - Sergio Recillas-Morales
- Faculty of Veterinary Medicine, Universidad Autónoma del Estado de México, Toluca, Estado de México, México
| | - José Arturo Avalos-Fuentes
- Departamento de Fisiología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, México, México
| | - Francisco Paz-Bermúdez
- Departamento de Fisiología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, México, México
| | - Gerardo Leyva-Gómez
- Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad de México, México
| | - Hernán Cortés
- Laboratorio de Medicina Genómica, Departamento de Genómica, Instituto Nacional de Rehabilitación Luis Guillermo Ibarra Ibarra, Ciudad de México, México
| | - Benjamín Florán
- Departamento de Fisiología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, México, México
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3
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G A, O P, E CM, M GR. Reduction of dopaminergic transmission in the globus pallidus increases anxiety-like behavior without altering motor activity. Behav Brain Res 2020; 386:112589. [PMID: 32194191 DOI: 10.1016/j.bbr.2020.112589] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 02/26/2020] [Accepted: 02/27/2020] [Indexed: 12/29/2022]
Abstract
The globus pallidus (GP) plays an important role in the flow of information between input and output structures of the basal ganglia (BG) circuit. In addition to participating in motor control, the GP may also be involved in cognitive and emotional functions related to the symptoms of patients with Parkinson's disease (PD). Since the GP receives dopaminergic innervation from the substantia nigra pars compacta (SNc), it is important to determine whether a local dopamine (DA) deficit in the GP is related not only to motor but also to the cognitive and emotional alterations of PD. The aim of this study was to examine the effects of lesions in the GP (induced by 6-OHDA) on anxiety, depression and ambulation in rats. Such lesions are known to reduce dopaminergic innervation in this brain structure. Additionally, the effect on DA receptors in the GP was tested by local administration of the dopamine agonist PD168,077, antagonist haloperidol and psychostimulant amphetamine. Experimental anxiety was evaluated with the elevated plus maze (EPM), burying behavior test (BBT) and social interaction test, while depressive-like behavior was assessed with the sucrose preference test. Rats with unilateral and bilateral lesions showed a higher level of anxiety than intact animals in both the EPM and BBT, an effect also obtained after intrapallidal injection of haloperidol. The administration of methamphetamine or PD-168.077 caused the opposite effect. The dopaminergic lesions in the GP did not affect sucrose preference, social interaction or ambulation. These results show that dopamine in the GP, acting through D2 or D4 receptors, may be involved in the manifestation of anxiety, a non-motor symptom of PD that often appears before motor symptoms.
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Affiliation(s)
- Avila G
- Escuela Nacional de Ciencias Biológicas, Instituto Politecnico Nacional, Wilfrido Massieu sn, San Pedro Zacatenco, CP 07738, Ciudad de México, Mexico
| | - Picazo O
- Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis y Diaz Mirón, Col. Santo Tomás CP.11340, Ciudad de México, Mexico
| | - Chuc-Meza E
- Escuela Nacional de Ciencias Biológicas, Instituto Politecnico Nacional, Wilfrido Massieu sn, San Pedro Zacatenco, CP 07738, Ciudad de México, Mexico
| | - García-Ramirez M
- Escuela Nacional de Ciencias Biológicas, Instituto Politecnico Nacional, Wilfrido Massieu sn, San Pedro Zacatenco, CP 07738, Ciudad de México, Mexico.
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Effects of local activation and blockade of dopamine D4 receptors in the spiking activity of the reticular thalamic nucleus in normal and in ipsilateral dopamine-depleted rats. Brain Res 2019; 1712:34-46. [DOI: 10.1016/j.brainres.2019.01.042] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 01/08/2019] [Accepted: 01/30/2019] [Indexed: 01/01/2023]
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Murata Y, Colonnese MT. Thalamic inhibitory circuits and network activity development. Brain Res 2019; 1706:13-23. [PMID: 30366019 PMCID: PMC6363901 DOI: 10.1016/j.brainres.2018.10.024] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 09/30/2018] [Accepted: 10/22/2018] [Indexed: 02/06/2023]
Abstract
Inhibitory circuits in thalamus and cortex shape the major activity patterns observed by electroencephalogram (EEG) in the adult brain. Their delayed maturation and circuit integration, relative to excitatory neurons, suggest inhibitory neuronal development could be responsible for the onset of mature thalamocortical activity. Indeed, the immature brain lacks many inhibition-dependent activity patterns, such as slow-waves, delta oscillations and sleep-spindles, and instead expresses other unique oscillatory activities in multiple species including humans. Thalamus contributes significantly to the generation of these early oscillations. Compared to the abundance of studies on the development of inhibition in cortex, however, the maturation of thalamic inhibition is poorly understood. Here we review developmental changes in the neuronal and circuit properties of the thalamic relay and its interconnected inhibitory thalamic reticular nucleus (TRN) both in vitro and in vivo, and discuss their potential contribution to early network activity and its maturation. While much is unknown, we argue that weak inhibitory function in the developing thalamus allows for amplification of thalamocortical activity that supports the generation of early oscillations. The available evidence suggests that the developmental acquisition of critical thalamic oscillations such as slow-waves and sleep-spindles is driven by maturation of the TRN. Further studies to elucidate thalamic GABAergic circuit formation in relation to thalamocortical network function would help us better understand normal as well as pathological brain development.
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Affiliation(s)
- Yasunobu Murata
- Department of Pharmacology and Physiology, and Institute for Neuroscience, George Washington University, 2300 Eye Street NW, Washington, DC 20037, USA.
| | - Matthew T Colonnese
- Department of Pharmacology and Physiology, and Institute for Neuroscience, George Washington University, 2300 Eye Street NW, Washington, DC 20037, USA.
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Liu J, Yao L, Zhang W, Deng W, Xiao Y, Li F, Sweeney JA, Gong Q, Lui S. Dissociation of fractional anisotropy and resting-state functional connectivity alterations in antipsychotic-naive first-episode schizophrenia. Schizophr Res 2019; 204:230-237. [PMID: 30121186 DOI: 10.1016/j.schres.2018.08.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 07/25/2018] [Accepted: 08/06/2018] [Indexed: 11/29/2022]
Abstract
Altered resting-state functional connectivity (rsFC) has been demonstrated between multiple brain regions in schizophrenia. However, whether these alterations are related to fractional anisotropy (FA) alterations in pathways that connect regions with altered rsFC remains unknown. In this study, diffusion tensor imaging and resting-state functional magnetic resonance imaging were performed with 181 antipsychotic-naïve first-episode schizophrenia patients and 173 matched healthy controls. FA was measured using tensor-guided tractography in identifiable pathways between selected pairs of brain regions with altered rsFC as determined by prior meta-analysis. Compared with controls, patients showed significantly decreased FA between right caudate nucleus and right pallidum, right caudate nucleus and right putamen, and right hippocampus and right thalamus. Decreased rsFC was observed between right pallidum and right thalamus, and right insula and right superior temporal gyrus. No significant correlation was observed between FA and rsFC. FA between right caudate nucleus and right putamen was inversely correlated with negative symptoms while rsFC between right pallidum and right thalamus was inversely correlated with positive symptoms. The lack of robust correlations between FA and rsFC and no overlap of these abnormalities indicate that regional rsFC alterations in the early course of schizophrenia are not primarily associated with FA alterations. The observation that positive and negative symptoms are related to different functional and structural disturbances is consistent with this dissociation, and with prior work suggests that different pathophysiological mechanism may underlie positive and negative symptoms in the early course of schizophrenia.
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Affiliation(s)
- Jieke Liu
- Huaxi Magnetic Resonance Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, China
| | - Li Yao
- Huaxi Magnetic Resonance Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, China
| | - Wenjing Zhang
- Huaxi Magnetic Resonance Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, China
| | - Wei Deng
- Department of Psychiatry, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, China
| | - Yuan Xiao
- Huaxi Magnetic Resonance Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, China
| | - Fei Li
- Huaxi Magnetic Resonance Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, China
| | - John A Sweeney
- Huaxi Magnetic Resonance Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, China; Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, OH, USA
| | - Qiyong Gong
- Huaxi Magnetic Resonance Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, China
| | - Su Lui
- Huaxi Magnetic Resonance Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, China.
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Zhou C, Gu W, Wu H, Yan X, Deshpande P, Xiao C, Lester HA. Bidirectional dopamine modulation of excitatory and inhibitory synaptic inputs to subthalamic neuron subsets containing α4β2 or α7 nAChRs. Neuropharmacology 2019; 148:220-228. [PMID: 30660626 DOI: 10.1016/j.neuropharm.2019.01.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 01/10/2019] [Accepted: 01/14/2019] [Indexed: 02/05/2023]
Abstract
The subthalamic nucleus (STN) possesses microcircuits distinguished by subtypes of nicotinic acetylcholine receptors (nAChRs). Although dysfunction of the STN is well-known in Parkinson's disease, there is still little information about whether dopamine differentially modulates excitatory and inhibitory synaptic inputs to STN neurons expressing different nAChR subtypes. To address this issue, we performed brain slice patch-clamp recordings on STN neurons, while we pharmacologically manipulated dopaminergic inputs. In STN neuron subsets containing either α4β2 or α7 nAChRs, D1 and D2 receptors respectively enhanced and inhibited spontaneous inhibitory and excitatory postsynaptic currents (sIPSCs and sEPSCs) and firing rates. The elevation of dopamine levels resulted in diverse regulations of synaptic transmission in these two neuron subsets, and interestingly, the dopamine regulation of sIPSCs significantly correlated with that of sEPSCs. Surprisingly, depletion of dopamine either by reserpine treatment or by unilateral 6-OHDA lesion of nigrostriatal dopaminergic neurons did not alter synaptic inputs to STN neurons, but STN neurons in the 6-OHDA-lesioned side exhibited hyperactivity. In summary, dopamine regulated both GABAergic and glutamatergic synaptic inputs to STN neuron subsets containing either α4β2 or α7 nAChRs, forming a balancing machinery to control neuronal activity. In parkinsonian mice, postsynaptic mechanisms may exist and contribute to the hyperactivity of STN neurons.
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Affiliation(s)
- Chunyi Zhou
- Jiangsu Province Key Laboratory in Anesthesiology, School of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu, 221004, China
| | - Weixin Gu
- Jiangsu Province Key Laboratory in Anesthesiology, School of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu, 221004, China
| | - Haichuan Wu
- Jiangsu Province Key Laboratory in Anesthesiology, School of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu, 221004, China
| | - Xiang Yan
- Jiangsu Province Key Laboratory in Anesthesiology, School of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu, 221004, China
| | - Purnima Deshpande
- Division of Biology, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Cheng Xiao
- Jiangsu Province Key Laboratory in Anesthesiology, School of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu, 221004, China; Division of Biology, California Institute of Technology, Pasadena, CA, 91125, USA.
| | - Henry A Lester
- Division of Biology, California Institute of Technology, Pasadena, CA, 91125, USA.
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8
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Davelaar EJ. Mechanisms of Neurofeedback: A Computation-theoretic Approach. Neuroscience 2018; 378:175-188. [DOI: 10.1016/j.neuroscience.2017.05.052] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 05/19/2017] [Accepted: 05/29/2017] [Indexed: 10/19/2022]
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Furth KE, McCoy AJ, Dodge C, Walters JR, Buonanno A, Delaville C. Neuronal correlates of ketamine and walking induced gamma oscillations in the medial prefrontal cortex and mediodorsal thalamus. PLoS One 2017; 12:e0186732. [PMID: 29095852 PMCID: PMC5667758 DOI: 10.1371/journal.pone.0186732] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 10/08/2017] [Indexed: 01/19/2023] Open
Abstract
Alterations in the function of the medial prefrontal cortex (mPFC) and its major thalamic source of innervation, the mediodorsal (MD) thalamus, have been hypothesized to contribute to the symptoms of schizophrenia. The NMDAR antagonist ketamine, used to model schizophrenia, elicits a brain state resembling early stage schizophrenia characterized by cognitive deficits and increases in cortical low gamma (40-70 Hz) power. Here we sought to determine how ketamine differentially affects spiking and gamma local field potential (LFP) activity in the rat mPFC and MD thalamus. Additionally, we investigated the ability of drugs targeting the dopamine D4 receptor (D4R) to modify the effects of ketamine on gamma activity as a measure of potential cognitive therapeutic efficacy. Rats were trained to walk on a treadmill to reduce confounds related to hyperactivity after ketamine administration (10 mg/kg s.c.) while recordings were obtained from electrodes chronically implanted in the mPFC and MD thalamus. Ketamine increased gamma LFP power in mPFC and MD thalamus in a similar frequency range, yet did not increase thalamocortical synchronization. Ketamine also increased firing rates and spike synchronization to gamma oscillations in the mPFC but decreased both measures in MD thalamus. Conversely, walking alone increased both firing rates and spike-gamma LFP correlations in both mPFC and MD thalamus. The D4R antagonist alone (L-745,870) had no effect on gamma LFP power during treadmill walking, although it reversed increases induced by the D4R agonist (A-412997) in both mPFC and MD thalamus. Neither drug altered ketamine-induced changes in gamma power or firing rates in the mPFC. However, in MD thalamus, the D4R agonist increased ketamine-induced gamma power and prevented ketamine's inhibitory effect on firing rates. Results provide new evidence that ketamine differentially modulates spiking and gamma power in MD thalamus and mPFC, supporting a potential role for both areas in contributing to ketamine-induced schizophrenia-like symptoms.
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Affiliation(s)
- Katrina E. Furth
- Neurophysiological Pharmacology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America
- Graduate Program for Neuroscience, Boston University, Boston, Massachusetts, United States of America
- Section on Molecular Neurobiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Alex J. McCoy
- Neurophysiological Pharmacology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Caroline Dodge
- Neurophysiological Pharmacology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Judith R. Walters
- Neurophysiological Pharmacology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Andres Buonanno
- Section on Molecular Neurobiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Claire Delaville
- Neurophysiological Pharmacology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America
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10
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Caballero-Florán RN, Conde-Rojas I, Oviedo Chávez A, Cortes-Calleja H, Lopez-Santiago LF, Isom LL, Aceves J, Erlij D, Florán B. Cannabinoid-induced depression of synaptic transmission is switched to stimulation when dopaminergic tone is increased in the globus pallidus of the rodent. Neuropharmacology 2016; 110:407-418. [PMID: 27506997 DOI: 10.1016/j.neuropharm.2016.08.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 08/02/2016] [Accepted: 08/05/2016] [Indexed: 11/27/2022]
Abstract
Because activation of D2 receptors reverses the neurochemical effects of cannabinoids, we examined whether increasing dopaminergic tone in the globus pallidus (GPe) switches cannabinoid induced depression of synaptic transmission. GABAergic synaptic currents evoked in pallidal neurons by stimulation of striatal projections (IPSCs) were depressed by perfusion with the CB1R agonist ACEA. Coactivation of D2Rs with quinpirole converted the depression into stimulation. Pretreatment with pertussis toxin (PTX) to limit Gi/o protein coupling also switched the CB1R-induced depression of IPSCs. The stimulation of IPSCs was blocked by the selective PKA blocker H89. Changes in the paired pulse ratio during both inhibitory and stimulatory responses indicate that the effects are due to changes in transmitter release. Postsynaptic depolarization induces endocannabinoid release that inhibits transmitter release (DSI). When D2Rs were activated with quinpirole, depolarization increased transmission instead of depressing it. This increase was blocked by AM251. We also examined the effects of CB1R/D2R coactivation on cAMP accumulation in the GPe to further verify that the AC/PKA cascade is involved. CB1R/D2R coactivation converted the inhibition of cAMP seen when each receptor is stimulated alone into a stimulation. We also determined the effects on turning behavior of unilateral injection of ACEA into the GPe of awake animals and its modification by dopamine antagonists. Blockade of D2 family receptors with sulpiride antagonized the motor effects of ACEA. We show, for the first time, that cannabinoid-inhibition of synaptic transmission in the GPe becomes a stimulation after D2Rs or PTX treatment and that the switch is probably relevant for the control of motor behavior.
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Affiliation(s)
- Rene Nahum Caballero-Florán
- Departamento de Farmacología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico
| | - Israel Conde-Rojas
- Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico
| | | | - Hernán Cortes-Calleja
- Laboratory of Genomic Medicine, Department of Genetics, National Rehabilitation Institute, Mexico City, Mexico
| | - Luis F Lopez-Santiago
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Lori L Isom
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Jorge Aceves
- Departamento de Farmacología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico
| | - David Erlij
- Department of Physiology SUNY Downstate Medical Center, Brooklyn, NY 11203, USA
| | - Benjamín Florán
- Departamento de Farmacología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico.
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Saunders A, Huang KW, Sabatini BL. Globus Pallidus Externus Neurons Expressing parvalbumin Interconnect the Subthalamic Nucleus and Striatal Interneurons. PLoS One 2016; 11:e0149798. [PMID: 26905595 PMCID: PMC4764347 DOI: 10.1371/journal.pone.0149798] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Accepted: 02/04/2016] [Indexed: 01/24/2023] Open
Abstract
The globus pallidus externus (GP) is a nucleus of the basal ganglia (BG), containing GABAergic projection neurons that arborize widely throughout the BG, thalamus and cortex. Ongoing work seeks to map axonal projection patterns from GP cell types, as defined by their electrophysiological and molecular properties. Here we use transgenic mice and recombinant viruses to characterize parvalbumin expressing (PV+) GP neurons within the BG circuit. We confirm that PV+ neurons 1) make up ~40% of the GP neurons 2) exhibit fast-firing spontaneous activity and 3) provide the major axonal arborization to the STN and substantia nigra reticulata/compacta (SNr/c). PV+ neurons also innervate the striatum. Retrograde labeling identifies ~17% of pallidostriatal neurons as PV+, at least a subset of which also innervate the STN and SNr. Optogenetic experiments in acute brain slices demonstrate that the PV+ pallidostriatal axons make potent inhibitory synapses on low threshold spiking (LTS) and fast-spiking interneurons (FS) in the striatum, but rarely on spiny projection neurons (SPNs). Thus PV+ GP neurons are synaptically positioned to directly coordinate activity between BG input nuclei, the striatum and STN, and thalamic-output from the SNr.
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Affiliation(s)
- Arpiar Saunders
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Kee Wui Huang
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Bernardo Luis Sabatini
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
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12
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Pérez-Fernández J, Megías M, Pombal MA. Expression of a Novel D4 Dopamine Receptor in the Lamprey Brain. Evolutionary Considerations about Dopamine Receptors. Front Neuroanat 2016; 9:165. [PMID: 26778974 PMCID: PMC4701969 DOI: 10.3389/fnana.2015.00165] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 12/08/2015] [Indexed: 12/28/2022] Open
Abstract
Numerous data reported in lampreys, which belong to the phylogenetically oldest branch of vertebrates, show that the dopaminergic system was already well developed at the dawn of vertebrate evolution. The expression of dopamine in the lamprey brain is well conserved when compared to other vertebrates, and this is also true for the D2 receptor. Additionally, the key role of dopamine in the striatum, modulating the excitability in the direct and indirect pathways through the D1 and D2 receptors, has also been recently reported in these animals. The moment of divergence regarding the two whole genome duplications occurred in vertebrates suggests that additional receptors, apart from the D1 and D2 previously reported, could be present in lampreys. We used in situ hybridization to characterize the expression of a novel dopamine receptor, which we have identified as a D4 receptor according to the phylogenetic analysis. The D4 receptor shows in the sea lamprey a more restricted expression pattern than the D2 subtype, as reported in mammals. Its main expression areas are the striatum, lateral and ventral pallial sectors, several hypothalamic regions, habenula, and mesencephalic and rhombencephalic motoneurons. Some expression areas are well conserved through vertebrate evolution, as is the case of the striatum or the habenula, but the controversies regarding the D4 receptor expression in other vertebrates hampers for a complete comparison, especially in rhombencephalic regions. Our results further support that the dopaminergic system in vertebrates is well conserved and suggest that at least some functions of the D4 receptor were already present before the divergence of lampreys.
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Affiliation(s)
- Juan Pérez-Fernández
- Neurolam Group, Department of Functional Biology and Health Sciences, Faculty of Biology - Centro de Investigaciones Biomédicas - Instituto de Investigación Biomédica de Vigo, Uiversity of Vigo Vigo, Spain
| | - Manuel Megías
- Neurolam Group, Department of Functional Biology and Health Sciences, Faculty of Biology - Centro de Investigaciones Biomédicas - Instituto de Investigación Biomédica de Vigo, Uiversity of Vigo Vigo, Spain
| | - Manuel A Pombal
- Neurolam Group, Department of Functional Biology and Health Sciences, Faculty of Biology - Centro de Investigaciones Biomédicas - Instituto de Investigación Biomédica de Vigo, Uiversity of Vigo Vigo, Spain
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Nakazawa S, Nakamichi K, Imai H, Ichihara J. Effect of dopamine D4 receptor agonists on sleep architecture in rats. Prog Neuropsychopharmacol Biol Psychiatry 2015; 63:6-13. [PMID: 25985889 DOI: 10.1016/j.pnpbp.2015.05.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2015] [Revised: 04/28/2015] [Accepted: 05/11/2015] [Indexed: 01/11/2023]
Abstract
Dopamine plays a key role in the regulation of sleep-wake states, as revealed by the observation that dopamine-releasing agents such as methylphenidate have wake-promoting effects. However, the precise mechanisms for the wake-promoting effect produced by the enhancement of dopamine transmission are not fully understood. Although dopamine D1, D2, and D3 receptors are known to have differential effects on sleep architecture, the role of D4 receptors (D4Rs), and particularly the influence of D4R activation on the sleep-wake state, has not been studied so far. In this study, we investigated for the first time the effects of two structurally different D4R agonists, Ro 10-5824 and A-412997, on the sleep-wake states in rats. We found that both D4R agonists generally increased waking duration, and conversely, reduced non-rapid eye movement (NREM) sleep duration in rats. The onset of NREM sleep was also generally delayed. However, only the A-412997 agonist (but not the Ro 10-5824) influenced rapid eye movement sleep onset and duration. Furthermore, these effects were accompanied with an enhancement of EEG spectral power in the theta and the gamma bands. Our results suggest the involvement of dopamine D4R in the regulation of sleep-wake states. The activation of the D4R could enhance the arousal states as revealed by the behavioral and electrophysiological patterns in this study. Dopamine D4R may contribute to the arousal effects of dopamine-releasing agents such as methylphenidate.
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Affiliation(s)
- Shunsuke Nakazawa
- Drug Development Research Laboratories, Sumitomo Dainippon Pharma, Co., Ltd., Osaka, Japan.
| | - Keiko Nakamichi
- Drug Development Research Laboratories, Sumitomo Dainippon Pharma, Co., Ltd., Osaka, Japan
| | - Hideaki Imai
- Drug Development Research Laboratories, Sumitomo Dainippon Pharma, Co., Ltd., Osaka, Japan
| | - Junji Ichihara
- Drug Development Research Laboratories, Sumitomo Dainippon Pharma, Co., Ltd., Osaka, Japan
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14
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Good CH, Wang H, Chen YH, Mejias-Aponte CA, Hoffman AF, Lupica CR. Dopamine D4 receptor excitation of lateral habenula neurons via multiple cellular mechanisms. J Neurosci 2013; 33:16853-64. [PMID: 24155292 PMCID: PMC3807019 DOI: 10.1523/jneurosci.1844-13.2013] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 08/15/2013] [Accepted: 09/05/2013] [Indexed: 12/31/2022] Open
Abstract
Glutamatergic lateral habenula (LHb) output communicates negative motivational valence to ventral tegmental area (VTA) dopamine (DA) neurons via activation of the rostromedial tegmental nucleus (RMTg). However, the LHb also receives a poorly understood DA input from the VTA, which we hypothesized constitutes an important feedback loop regulating DA responses to stimuli. Using whole-cell electrophysiology in rat brain slices, we find that DA initiates a depolarizing inward current (I(DAi)) and increases spontaneous firing in 32% of LHb neurons. I(DAi) was also observed upon application of amphetamine or the DA uptake blockers cocaine or GBR12935, indicating involvement of endogenous DA. I(DAi) was blocked by D4 receptor (D4R) antagonists (L745,870 or L741,742), and mimicked by a selective D4R agonist (A412997). I(DAi) was associated with increased whole-cell conductance and was blocked by Cs+ or a selective blocker of hyperpolarization-activated cyclic nucleotide-gated (HCN) ion channel, ZD7288. I(DAi) was also associated with a depolarizing shift in half-activation voltage for the hyperpolarization-activated cation current (Ih) mediated by HCN channels. Recordings from LHb neurons containing fluorescent retrograde tracers revealed that I(DAi) was observed only in cells projecting to the RMTg and not the VTA. In parallel with direct depolarization, DA also strongly increased synaptic glutamate release and reduced synaptic GABA release onto LHb cells. These results demonstrate that DA can excite glutamatergic LHb output to RMTg via multiple cellular mechanisms. Since the RMTg strongly inhibits midbrain DA neurons, activation of LHb output to RMTg by DA represents a negative feedback loop that may dampen DA neuron output following activation.
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Affiliation(s)
- Cameron H. Good
- Cellular Neurobiology Research Branch
- Electrophysiology Research Section, and
| | - Huikun Wang
- Cellular Neurobiology Research Branch
- Electrophysiology Research Section, and
| | - Yuan-Hao Chen
- Department of Neurosurgery, Tri-Service General Hospital, National Defense Medical Center, Taipei 114, Taiwan, Republic of China
| | - Carlos A. Mejias-Aponte
- Integrative Neuroscience Research Branch, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, US Department of Health and Human Services, Baltimore, Maryland 21224, and
| | | | - Carl R. Lupica
- Cellular Neurobiology Research Branch
- Electrophysiology Research Section, and
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15
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Furth KE, Mastwal S, Wang KH, Buonanno A, Vullhorst D. Dopamine, cognitive function, and gamma oscillations: role of D4 receptors. Front Cell Neurosci 2013; 7:102. [PMID: 23847468 PMCID: PMC3698457 DOI: 10.3389/fncel.2013.00102] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2013] [Accepted: 06/11/2013] [Indexed: 12/29/2022] Open
Abstract
Cognitive deficits in individuals with schizophrenia (SCZ) are considered core symptoms of this disorder, and can manifest at the prodromal stage. Antipsychotics ameliorate positive symptoms but only modestly improve cognitive symptoms. The lack of treatments that improve cognitive abilities currently represents a major obstacle in developing more effective therapeutic strategies for this debilitating disorder. While D4 receptor (D4R)-specific antagonists are ineffective in the treatment of positive symptoms, animal studies suggest that D4R drugs can improve cognitive deficits. Moreover, recent work from our group suggests that D4Rs synergize with the neuregulin/ErbB4 signaling pathway, genetically identified as risk factors for SCZ, in parvalbumin (PV)-expressing interneurons to modulate gamma oscillations. These high-frequency network oscillations correlate with attention and increase during cognitive tasks in healthy subjects, and this correlation is attenuated in affected individuals. This finding, along with other observations indicating impaired GABAergic function, has led to the idea that abnormal neural activity in the prefrontal cortex (PFC) in individuals with SCZ reflects a perturbation in the balance of excitation and inhibition. Here we review the current state of knowledge of D4R functions in the PFC and hippocampus, two major brain areas implicated in SCZ. Special emphasis is given to studies focusing on the potential role of D4Rs in modulating GABAergic transmission and to an emerging concept of a close synergistic relationship between dopamine/D4R and neuregulin/ErbB4 signaling pathways that tunes the activity of PV interneurons to regulate gamma frequency network oscillations and potentially cognitive processes.
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Affiliation(s)
- Katrina E Furth
- Section on Molecular Neurobiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health Bethesda, MD, USA ; Graduate Program for Neuroscience, Boston University Boston, MA, USA
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16
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Yang C, Ge SN, Zhang JR, Chen L, Yan ZQ, Heng LJ, Zhao TZ, Li WX, Jia D, Zhu JL, Gao GD. Systemic blockade of dopamine D2-like receptors increases high-voltage spindles in the globus pallidus and motor cortex of freely moving rats. PLoS One 2013; 8:e64637. [PMID: 23755132 PMCID: PMC3674001 DOI: 10.1371/journal.pone.0064637] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Accepted: 04/09/2013] [Indexed: 12/02/2022] Open
Abstract
High-voltage spindles (HVSs) have been reported to appear spontaneously and widely in the cortical–basal ganglia networks of rats. Our previous study showed that dopamine depletion can significantly increase the power and coherence of HVSs in the globus pallidus (GP) and motor cortex of freely moving rats. However, it is unclear whether dopamine regulates HVS activity by acting on dopamine D1-like receptors or D2-like receptors. We employed local-field potential and electrocorticogram methods to simultaneously record the oscillatory activities in the GP and primary motor cortex (M1) in freely moving rats following systemic administration of dopamine receptor antagonists or saline. The results showed that the dopamine D2-like receptor antagonists, raclopride and haloperidol, significantly increased the number and duration of HVSs, and the relative power associated with HVS activity in the GP and M1 cortex. Coherence values for HVS activity between the GP and M1 cortex area were also significantly increased by dopamine D2-like receptor antagonists. On the contrary, the selective dopamine D1-like receptor antagonist, SCH23390, had no significant effect on the number, duration, or relative power of HVSs, or HVS-related coherence between M1 and GP. In conclusion, dopamine D2-like receptors, but not D1-like receptors, were involved in HVS regulation. This supports the important role of dopamine D2-like receptors in the regulation of HVSs. An siRNA knock-down experiment on the striatum confirmed our conclusion.
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Affiliation(s)
- Chen Yang
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, Xi'an, People’s Republic of China
| | - Shun-Nan Ge
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, Xi'an, People’s Republic of China
| | - Jia-Rui Zhang
- Department of Pathology, Tangdu Hospital, Fourth Military Medical University, Xi'an, People’s Republic of China
| | - Lei Chen
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, Xi'an, People’s Republic of China
| | - Zhi-Qiang Yan
- Department of Neurosurgery, Urumqi General Hospital of Lanzhou Military Command, Urumqi, People’s Republic of China
| | - Li-Jun Heng
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, Xi'an, People’s Republic of China
| | - Tian-Zhi Zhao
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, Xi'an, People’s Republic of China
| | - Wei-Xin Li
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, Xi'an, People’s Republic of China
| | - Dong Jia
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, Xi'an, People’s Republic of China
| | - Jun-Ling Zhu
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, Xi'an, People’s Republic of China
- * E-mail: (GDG); (JLZ)
| | - Guo-Dong Gao
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, Xi'an, People’s Republic of China
- * E-mail: (GDG); (JLZ)
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Bazyan AS, van Luijtelaar G. Neurochemical and behavioral features in genetic absence epilepsy and in acutely induced absence seizures. ISRN NEUROLOGY 2013; 2013:875834. [PMID: 23738145 PMCID: PMC3664506 DOI: 10.1155/2013/875834] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Accepted: 02/06/2013] [Indexed: 02/08/2023]
Abstract
The absence epilepsy typical electroencephalographic pattern of sharp spikes and slow waves (SWDs) is considered to be due to an interaction of an initiation site in the cortex and a resonant circuit in the thalamus. The hyperpolarization-activated cyclic nucleotide-gated cationic I h pacemaker channels (HCN) play an important role in the enhanced cortical excitability. The role of thalamic HCN in SWD occurrence is less clear. Absence epilepsy in the WAG/Rij strain is accompanied by deficiency of the activity of dopaminergic system, which weakens the formation of an emotional positive state, causes depression-like symptoms, and counteracts learning and memory processes. It also enhances GABAA receptor activity in the striatum, globus pallidus, and reticular thalamic nucleus, causing a rise of SWD activity in the cortico-thalamo-cortical networks. One of the reasons for the occurrence of absences is that several genes coding of GABAA receptors are mutated. The question arises: what the role of DA receptors is. Two mechanisms that cause an infringement of the function of DA receptors in this genetic absence epilepsy model are proposed.
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Affiliation(s)
- A. S. Bazyan
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Science, Russian Federation, 5A Butlerov Street, Moscow 117485, Russia
| | - G. van Luijtelaar
- Biological Psychology, Donders Centre for Cognition, Donders Institute for Brain, Cognition and Behavior, Radboud University Nijmegen, P.O. Box 9104, 6500 HE Nijmegen, The Netherlands
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18
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Dopaminergic modulation of tonic but not phasic GABAA-receptor-mediated current in the ventrobasal thalamus of Wistar and GAERS rats. Exp Neurol 2013; 247:1-7. [PMID: 23562670 DOI: 10.1016/j.expneurol.2013.03.023] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Revised: 03/14/2013] [Accepted: 03/22/2013] [Indexed: 11/24/2022]
Abstract
Activation of GABA(A) receptors by GABA causes phasic and tonic conductances in different brain areas. In the ventrobasal (VB) thalamus, tonic inhibition originates from GABA acting on extrasynaptic receptors. Here we show that dopamine (DA), the D2-like agonist quinpirole and the selective D4R agonist PD-168,077 decrease the magnitude of the tonic GABA(A) current while D1-like agonist SKF39383 lacks any significant effects in VB neurons of Wistar rats. On the other hand, DA and D1/D2 receptor activation does not alter phasic GABA(A) conductance. As we previously reported that an increased tonic GABA(A) current in VB neurons is critical for absence seizure generation, we also investigated whether D2-D4 receptor activation is capable of normalizing this aberrant conductance in genetic absence epilepsy rats from Strasbourg (GAERS). Quinpirole and PD-168,077 selectively reduces tonic GABA(A) current as in normal rats. Therefore, it is conceivable that some DA anti-absence effects occur via modulation of tonic GABA(A) current in the VB.
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Cruz-Trujillo R, Avalos-Fuentes A, Rangel-Barajas C, Paz-Bermúdez F, Sierra A, Escartín-Perez E, Aceves J, Erlij D, Florán B. D3 dopamine receptors interact with dopamine D1 but not D4 receptors in the GABAergic terminals of the SNr of the rat. Neuropharmacology 2013; 67:370-8. [DOI: 10.1016/j.neuropharm.2012.11.032] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Revised: 11/29/2012] [Accepted: 11/30/2012] [Indexed: 11/29/2022]
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20
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Erlij D, Acosta-García J, Rojas-Márquez M, González-Hernández B, Escartín-Perez E, Aceves J, Florán B. Dopamine D4 receptor stimulation in GABAergic projections of the globus pallidus to the reticular thalamic nucleus and the substantia nigra reticulata of the rat decreases locomotor activity. Neuropharmacology 2011; 62:1111-8. [PMID: 22108379 DOI: 10.1016/j.neuropharm.2011.11.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Revised: 11/01/2011] [Accepted: 11/02/2011] [Indexed: 11/28/2022]
Abstract
Dopamine D4 receptors are localized in the GABAergic projections that globus pallidus (GP) neurons send to the reticular nucleus of the thalamus (RTN), the substantia nigra reticulata (SNr) and the subthalamic nucleus (STN). Deficient D4 function in this network could lead to hyperactivity and thus be important in generating some of the symptoms of ADHD (attention deficit hyperactivity disorder), a condition associated with polymorphisms of dopamine D4 receptors. It is then, unexpected that systemic injections of D4 ligands have no significant effects on the motor activity of normal rats. We further examined this issue by microinjecting D4 ligands and psychostimulant drugs in relevant structures. Interstitial dopamine overflow in the RTN was increased by reverse microdialysis of both methylphenidate and methamphetamine. Intranuclear injections in the RTN of methylphenidate, methamphetamine and the selective D4 agonist PD 168,077 reduced motor activity. Intraperitoneal injection of the D4 antagonist L 745,870 blocked the effects of these intranuclear injections. Similarly, intranuclear injections of PD 168,077 in the SNr inhibited motor activity, an effect that was also blocked by intraperitoneal L 745,870. In rats with 6-OHDA induced hemiparkinsonism, intraperitoneal PD 168,077 produced ipsilateral turning behavior that was blocked by L 745,870. Our results suggest that diminished D4 signaling in GP projections could lead to increased traffic through the relay nuclei of the thalamus and hyperactivity. Hence this basal-ganglia-thalamus network may be one of the targets of the beneficial effects that psychostimulant drugs have in disorders associated with D4 receptor abnormalities. This article is part of a Special Issue entitled 'Post-Traumatic Stress Disorder'.
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Affiliation(s)
- David Erlij
- Department of Physiology, SUNY Downstate Medical Center, NY, USA
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21
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Mabrouk OS, Li Q, Song P, Kennedy RT. Microdialysis and mass spectrometric monitoring of dopamine and enkephalins in the globus pallidus reveal reciprocal interactions that regulate movement. J Neurochem 2011; 118:24-33. [PMID: 21534957 PMCID: PMC3112281 DOI: 10.1111/j.1471-4159.2011.07293.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Pallidal dopamine, GABA and the endogenous opioid peptides enkephalins have independently been shown to be important controllers of sensorimotor processes. Using in vivo microdialysis coupled to liquid chromatography-mass spectrometry and a behavioral assay, we explored the interaction between these three neurotransmitters in the rat globus pallidus. Amphetamine (3 mg/kg i.p.) evoked an increase in dopamine, GABA and methionine/leucine enkephalin. Local perfusion of the dopamine D(1) receptor antagonist SCH 23390 (100 μM) fully prevented amphetamine stimulated enkephalin and GABA release in the globus pallidus and greatly suppressed hyperlocomotion. In contrast, the dopamine D(2) receptor antagonist raclopride (100 μM) had only minimal effects suggesting a greater role for pallidal D(1) over D(2) receptors in the regulation of movement. Under basal conditions, opioid receptor blockade by naloxone perfusion (10 μM) in the globus pallidus stimulated GABA and inhibited dopamine release. Amphetamine-stimulated dopamine release and locomotor activation were attenuated by naloxone perfusion with no effect on GABA. These findings demonstrate a functional relationship between pallidal dopamine, GABA and enkephalin systems in the control of locomotor behavior under basal and stimulated conditions. Moreover, these findings demonstrate the usefulness of liquid chromatography-mass spectrometry as an analytical tool when coupled to in vivo microdialysis.
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Affiliation(s)
- Omar S Mabrouk
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan, USA
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de Jesús Aceves J, Rueda-Orozco PE, Hernández R, Plata V, Ibañez-Sandoval O, Galarraga E, Bargas J. Dopaminergic presynaptic modulation of nigral afferents: its role in the generation of recurrent bursting in substantia nigra pars reticulata neurons. Front Syst Neurosci 2011; 5:6. [PMID: 21347219 PMCID: PMC3039203 DOI: 10.3389/fnsys.2011.00006] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Accepted: 01/23/2011] [Indexed: 11/13/2022] Open
Abstract
Previous work has shown the functions associated with activation of dopamine presynaptic receptors in some substantia nigra pars reticulata (SNr) afferents: (i) striatonigral terminals (direct pathway) posses presynaptic dopamine D1-class receptors whose action is to enhance inhibitory postsynaptic currents (IPSCs) and GABA transmission. (ii) Subthalamonigral terminals posses D1- and D2-class receptors where D1-class receptor activation enhances and D2-class receptor activation decreases excitatory postsynaptic currents. Here we report that pallidonigral afferents posses D2-class receptors (D3 and D4 types) that decrease inhibitory synaptic transmission via presynaptic modulation. No action of D1-class agonists was found on pallidonigral synapses. In contrast, administration of D1-receptor antagonists greatly decreased striatonigral IPSCs in the same preparation, suggesting that tonic dopamine levels help in maintaining the function of the striatonigral (direct) pathway. When both D3 and D4 type receptors were blocked, pallidonigral IPSCs increased in amplitude while striatonigral connections had no significant change, suggesting that tonic dopamine levels are repressing a powerful inhibition conveyed by pallidonigral synapses (a branch of the indirect pathway). We then blocked both D1- and D2-class receptors to acutely decrease direct pathway (striatonigral) and enhance indirect pathways (subthalamonigral and pallidonigral) synaptic force. The result was that most SNr projection neurons entered a recurrent bursting firing mode similar to that observed during Parkinsonism in both patients and animal models. These results raise the question as to whether the lack of dopamine in basal ganglia output nuclei is enough to generate some pathological signs of Parkinsonism.
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Affiliation(s)
- José de Jesús Aceves
- División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México Distrito Federal México, México
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