1
|
Garduño-Gutiérrez R, León-Olea M, Rodríguez-Manzo G. Opioid receptor and β-arrestin2 densities and distribution change after sexual experience in the ventral tegmental area of male rats. Physiol Behav 2018; 189:107-115. [DOI: 10.1016/j.physbeh.2018.03.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 03/17/2018] [Accepted: 03/17/2018] [Indexed: 12/21/2022]
|
2
|
Ago Y, Hasebe S, Hiramatsu N, Mori K, Watabe Y, Onaka Y, Hashimoto H, Takuma K, Matsuda T. Involvement of GABAA receptors in 5-HT1A and σ1 receptor synergism on prefrontal dopaminergic transmission under circulating neurosteroid deficiency. Psychopharmacology (Berl) 2016; 233:3125-34. [PMID: 27339616 DOI: 10.1007/s00213-016-4353-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 06/09/2016] [Indexed: 12/29/2022]
Abstract
RATIONALE We previously reported that the fluvoxamine-induced increase in prefrontal dopamine levels is enhanced by adrenalectomy/castration (which results in circulating neurosteroid deficiency), via combined activation of serotonin1A (5-HT1A) and σ1 receptors. However, the mechanistic details of the interaction between 5-HT1A and σ1 receptors are unknown. OBJECTIVES Because most neurosteroids have affinity for γ-aminobutyric acid (GABA)A receptors, in the present study, we examined the involvement of GABAA receptors in this process. RESULTS Adrenalectomy/castration decreased pentobarbital-induced sleeping time in mice, suggesting that it reduced GABAA receptor function. The GABAA receptor antagonist picrotoxin (1 mg/kg) enhanced the fluvoxamine-induced increase in prefrontal dopamine, but not noradrenaline or serotonin, levels in mice, suggesting that picrotoxin mimicked the effect of adrenalectomy/castration. Picrotoxin also potentiated the increase in prefrontal dopamine levels mediated by co-administration of the 5-HT1A receptor agonist osemozotan and the σ1 receptor agonist (+)-SKF-10,047, while it did not affect the co-administration-induced changes in noradrenaline and serotonin levels. Conversely, the GABAA receptor agonist diazepam (1 mg/kg) blocked the effect of adrenalectomy/castration on the fluvoxamine-induced increase in prefrontal dopamine levels. Co-administration of osemozotan and (+)-SKF-10,047 did not affect the expression of the neuronal activity marker c-Fos in the prefrontal cortex, ventral tegmental area, and nucleus accumbens in control mice, while it increased the c-Fos expression only in the prefrontal cortex and ventral tegmental area in picrotoxin-treated mice. CONCLUSIONS These results suggest that the GABAA receptor plays a key role in mediating the synergistic effects of 5-HT1A and σ1 receptor activation on prefrontal dopamine neurotransmission.
Collapse
Affiliation(s)
- Yukio Ago
- Laboratory of Medicinal Pharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamada-oka, Suita, Osaka, 565-0871, Japan
- Laboratory of Molecular Neuropharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - Shigeru Hasebe
- Laboratory of Medicinal Pharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamada-oka, Suita, Osaka, 565-0871, Japan
- Department of Pharmacology, Graduate School of Dentistry, Osaka University, 1-8 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - Naoki Hiramatsu
- Laboratory of Medicinal Pharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - Kazuya Mori
- Laboratory of Medicinal Pharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - Yuji Watabe
- Laboratory of Medicinal Pharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - Yusuke Onaka
- Laboratory of Medicinal Pharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - Hitoshi Hashimoto
- Laboratory of Molecular Neuropharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamada-oka, Suita, Osaka, 565-0871, Japan
- United Graduate School of Child Development, Osaka University, Kanazawa University, Hamamatsu University School of Medicine, Chiba University and University of Fukui, 2-2 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - Kazuhiro Takuma
- Department of Pharmacology, Graduate School of Dentistry, Osaka University, 1-8 Yamada-oka, Suita, Osaka, 565-0871, Japan
- United Graduate School of Child Development, Osaka University, Kanazawa University, Hamamatsu University School of Medicine, Chiba University and University of Fukui, 2-2 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - Toshio Matsuda
- Laboratory of Medicinal Pharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamada-oka, Suita, Osaka, 565-0871, Japan.
| |
Collapse
|
3
|
Del Cid-Pellitero E, Garzón M. Hypocretin1/orexinA-immunoreactive axons form few synaptic contacts on rat ventral tegmental area neurons that project to the medial prefrontal cortex. BMC Neurosci 2014; 15:105. [PMID: 25194917 PMCID: PMC4167264 DOI: 10.1186/1471-2202-15-105] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2014] [Accepted: 08/28/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Hypocretins/orexins (Hcrt/Ox) are hypothalamic neuropeptides involved in sleep-wakefulness regulation. Deficiency in Hcrt/Ox neurotransmission results in the sleep disorder narcolepsy, which is characterized by an inability to maintain wakefulness. The Hcrt/Ox neurons are maximally active during wakefulness and project widely to the ventral tegmental area (VTA). A dopamine-containing nucleus projecting extensively to the cerebral cortex, the VTA enhances wakefulness. In the present study, we used retrograde tracing from the medial prefrontal cortex (mPFC) to examine whether Hcrt1/OxA neurons target VTA neurons that could sustain behavioral wakefulness through their projections to mPFC. RESULTS The retrograde tracer Fluorogold (FG) was injected into mPFC and, after an optimal survival period, sections through the VTA were processed for dual immunolabeling of anti-FG and either anti-Hcrt1/OxA or anti-TH antisera. Most VTA neurons projecting to the mPFC were located in the parabrachial nucleus of the ipsilateral VTA and were non-dopaminergic. Only axonal profiles showed Hcrt1/OxA-immunoreactivity in VTA. Hcrt1/OxA reactivity was observed in axonal boutons and many unmyelinated axons. The Hcrt1/OxA immunoreactivity was found filling axons but it was also observed in parts of the cytoplasm and dense-core vesicles. Hcrt1/OxA-labeled boutons frequently apposed FG-immunolabeled dendrites. However, Hcrt1/OxA-labeled boutons rarely established synapses, which, when they were established, were mainly asymmetric (excitatory-type), with either FG-labeled or unlabeled dendrites. CONCLUSIONS Our results provide ultrastructural evidence that Hcrt1/OxA neurons may exert a direct synaptic influence on mesocortical neurons that would facilitate arousal and wakefulness. The paucity of synapses, however, suggest that the activity of VTA neurons with cortical projections might also be modulated by Hcrt1/OxA non-synaptic actions. In addition, Hcrt1/OxA could modulate the postsynaptic excitatory responses of VTA neurons with cortical projections to a co-released excitatory transmitter from Hcrt1/OxA axons. Our observation of Hcrt1/OxA targeting of mesocortical neurons supports Hcrt1/OxA wakefulness enhancement in the VTA and could help explain the characteristic hypersomnia present in narcoleptic patients.
Collapse
Affiliation(s)
| | - Miguel Garzón
- Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de Madrid, Arzobispo Morcillo 4, 28029 Madrid, Spain.
| |
Collapse
|
4
|
Blasio A, Steardo L, Sabino V, Cottone P. Opioid system in the medial prefrontal cortex mediates binge-like eating. Addict Biol 2014; 19:652-62. [PMID: 23346966 DOI: 10.1111/adb.12033] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Binge eating disorder is an addiction-like disorder characterized by excessive food consumption within discrete periods of time. This study was aimed at understanding the role of the opioid system within the medial prefrontal cortex (mPFC) in the consummatory and motivational aspects of binge-like eating. For this purpose, we trained male rats to obtain either a sugary, highly palatable diet (Palatable rats) or a chow diet (Chow rats) for 1 hour/day. We then evaluated the effects of the opioid receptor antagonist, naltrexone, given either systemically or site-specifically into the nucleus accumbens (NAcc) or the mPFC on a fixed ratio 1 (FR1) and a progressive ratio schedule of reinforcement for food. Finally, we assessed the expression of the genes proopiomelanocortin (POMC), pro-dynorphin (PDyn) and pro-enkephalin (PEnk), coding for the opioids peptides in the NAcc and the mPFC in both groups. Palatable rats rapidly escalated their intake by four times. Naltrexone, when administered systemically and into the NAcc, reduced FR1 responding for food and motivation to eat under a progressive ratio in both Chow and Palatable rats; conversely, when administered into the mPFC, the effects were highly selective for binge eating rats. Furthermore, we found a twofold increase in POMC and a ∼50% reduction in PDyn gene expression in the mPFC of Palatable rats, when compared to control rats; however, no changes were observed in the NAcc. Our data suggest that neuroadaptations of the opioid system in the mPFC occur following intermittent access to highly palatable food, which may be responsible for the development of binge-like eating.
Collapse
Affiliation(s)
- Angelo Blasio
- Laboratory of Addictive Disorders; Departments of Pharmacology and Psychiatry; Boston University School of Medicine; Boston MA USA
| | - Luca Steardo
- Department of Physiology and Pharmacology; University of Rome ‘Sapienza’; Italy
| | - Valentina Sabino
- Laboratory of Addictive Disorders; Departments of Pharmacology and Psychiatry; Boston University School of Medicine; Boston MA USA
| | - Pietro Cottone
- Laboratory of Addictive Disorders; Departments of Pharmacology and Psychiatry; Boston University School of Medicine; Boston MA USA
| |
Collapse
|
5
|
Cid-Pellitero ED, Garzon M. Hypocretin1/OrexinA Axon Targeting of Laterodorsal Tegmental Nucleus Neurons Projecting to the Rat Medial Prefrontal Cortex. Cereb Cortex 2011; 21:2762-73. [DOI: 10.1093/cercor/bhr070] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
6
|
Cid-Pellitero ED, GarzÓN M. Hypocretin1/OrexinA-containing axons innervate locus coeruleus neurons that project to the Rat medial prefrontal cortex. Implication in the sleep-wakefulness cycle and cortical activation. Synapse 2011; 65:843-57. [DOI: 10.1002/syn.20912] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Accepted: 01/09/2010] [Indexed: 12/31/2022]
|
7
|
Del Cid-Pellitero E, Garzón M. Medial prefrontal cortex receives input from dorsal raphe nucleus neurons targeted by hypocretin1/orexinA-containing axons. Neuroscience 2010; 172:30-43. [PMID: 21036204 DOI: 10.1016/j.neuroscience.2010.10.058] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Revised: 09/27/2010] [Accepted: 10/21/2010] [Indexed: 11/29/2022]
Abstract
The medial prefrontal cortex (mPFC) is strongly involved in cognition and behavior. It receives input from brainstem nuclei implicated in behavioral wakefulness and electrographic cortical activation, such as the dorsal raphe nucleus (DRN). Moreover, the hypocretinergic/orexinergic (Hcrt/Ox) hypothalamic neurons innervate DRN, thus modulating its activity and presumably allowing transitions between sleep-wakefulness cycle states. Dysfunction in this system is associated with narcolepsy. In this study we aimed to determine the precise location of DRN neurons projecting to mPFC and the extent to which they contain serotonin (5-hydroxytryptamine); we have also assessed whether Hcrt1/OxA neurons innervate DRN neurons that could sustain behavioral wakefulness through their projections to mPFC. The retrograde tracer Fluorogold was injected into mPFC and DRN sections were processed for double immunolabeling of anti-Fluorogold and either anti-5-hydroxytryptamine or anti-Hcrt1/OxA antisera. Most DRN neurons projecting to mPFC were located in the ventral sector of the rostral and intermediate DRN, and around half of them were serotonergic. Hcrt1/OxA-immunoreactivity in DRN was observed in unmyelinated axons and axon boutons (varicosities or axon terminals). Hcrt1/OxA immunoreactivity was observed within the cytoplasm and in dense-cored vesicles of these axons. Hcrt1/OxA-labeled boutons established both asymmetric synapses (n=30) and appositional contacts (n=102) with Fluorogold-labeled dendrites belonging to DRN neurons projecting to mPFC. Our results show that Hcrt1/OxA neurons may exert a direct synaptic influence on DRN neurons that could facilitate wakefulness, although other non-synaptic actions through volume transmission are also suggested.
Collapse
Affiliation(s)
- E Del Cid-Pellitero
- Department of Anatomy, Histology and Neuroscience, Medical School, Autónoma University of Madrid, Instituto de Investigación Hospital Universitario La Paz (IDIPAZ), Paseo de la Castellana 261, 28046 Madrid, Spain
| | | |
Collapse
|
8
|
Feeding association between the nucleus of the solitary tract and the ventral tegmental area. Appetite 2009; 53:457-60. [DOI: 10.1016/j.appet.2009.09.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2009] [Revised: 08/31/2009] [Accepted: 09/06/2009] [Indexed: 11/23/2022]
|
9
|
Lessard A, Savard M, Gobeil F, Pierce JP, Pickel VM. The neurokinin-3 (NK3) and the neurokinin-1 (NK1) receptors are differentially targeted to mesocortical and mesolimbic projection neurons and to neuronal nuclei in the rat ventral tegmental area. Synapse 2009; 63:484-501. [PMID: 19224600 PMCID: PMC2742351 DOI: 10.1002/syn.20627] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Tonic activation of neurokinin-3 (NK(3)) receptors in dopamine neurons of the ventral tegmental area (VTA) has been implicated in the pathophysiology of schizophrenia. This psychiatric disorder is associated with a dysfunctional activity in VTA projection neurons that can affect cognitive function at the level of the medial prefrontal cortex (mPFC) as well as motor and motivational states controlled in part by mesolimbic output to the nucleus accumbens (Acb). To determine the relevant sites for NK(3) receptor activation within this neuronal network, we used confocal and electron microscopy to examine NK(3) receptors (Cy5; immunogold) and retrograde labeling of fluorogold (FG, FITC; immunoperoxidase) in the VTA of rats receiving either Acb or mPFC injections of FG. Comparison was made with neurokinin-1 (NK(1)) receptors, which are also present, but less abundant then NK(3) receptors, in dopaminergic and GABAergic VTA neurons. There were no observable differences between NK(3) and NK(1) receptors in their primary locations in the cytoplasm and on the plasma membrane of VTA somata and dendrites with or without FG. Dendrites labeled with FG retrogradely transported from mPFC, however, contained more NK(3) or less NK(1) immunogold particles (plasmalemmal + cytoplasmic) then those retrogradely labeled following FG injection in the Acb. Moreover, only the NK(3) receptors were detected in neuronal nuclei in the VTA and in the nuclei of human HEK-293T NK(3)-transfected cells. The enrichment of NK(3) receptors in mesocortical projection neurons and nuclear distribution of these receptors may provide insight for understanding the selective antipsychotic effectiveness of NK(3) antagonists.
Collapse
Affiliation(s)
- Andrée Lessard
- Dept. Neurology and Neuroscience, Weill Medical College of Cornell University, New York, NY 10021
| | - Martin Savard
- Dept. Pharmacology, Faculty of Medicine, Université de Sherbrooke, Sherbrooke, Québec, Canada J1H 5N4
| | - Fernand Gobeil
- Dept. Pharmacology, Faculty of Medicine, Université de Sherbrooke, Sherbrooke, Québec, Canada J1H 5N4
| | - Joseph P. Pierce
- Dept. Neurology and Neuroscience, Weill Medical College of Cornell University, New York, NY 10021
| | - Virginia M. Pickel
- Dept. Neurology and Neuroscience, Weill Medical College of Cornell University, New York, NY 10021
| |
Collapse
|
10
|
Vittoz NM, Schmeichel B, Berridge CW. Hypocretin /orexin preferentially activates caudomedial ventral tegmental area dopamine neurons. Eur J Neurosci 2009; 28:1629-40. [PMID: 18973582 DOI: 10.1111/j.1460-9568.2008.06453.x] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The hypocretin/orexin (HCRT) neuropeptide system modulates behavioral state and state-dependent processes via actions on multiple neuromodulatory transmitter systems. Recent studies indicate that HCRT selectively increases dopamine (DA) neurotransmission within the prefrontal cortex (PFC) and the shell subregion of the nucleus accumbens (NAs), but not the core subregion of the nucleus accumbens (NAc). The circuitry underlying the differential actions of HCRT across distinct DA systems is unclear. The current study examined whether HCRT preferentially activates PFC- and NAs-projecting relative to NAc-projecting DA neurons within the VTA. One week after infusion of the retrograde tracer fluorogold (FG) into the medial PFC, NAc or NAs, animals received a ventricular infusion of HCRT-1. Subsequent analyses conducted across the rostral-caudal extent of the VTA determined the degree to which: (i) Fos-immunoreactivity (ir) was observed within tyrosine hydroxylase (TH)-ir neurons; (ii) TH-ir was observed within FG-ir neurons; and (iii) Fos-ir was observed within FG-ir neurons. HCRT significantly increased Fos-ir in VTA DA (TH-ir) neurons, primarily in a restricted population of small-to-medium-sized DA neurons located within the caudomedial VTA. Furthermore, within this region of the VTA, PFC- and NAs-projecting TH-ir neurons were more likely to contain Fos-ir than were NAc-projecting TH-ir neurons. These results provide novel evidence that HCRT selectively activates PFC- and NAs-projecting DA neurons within the VTA, and suggest a potential role for HCRT in PFC- and NAs-dependent cognitive and/or affective processes. Moreover, these and other observations suggest that the dysregulation of HCRT-DA interactions could contribute to cognitive/affective dysfunction associated with a variety of behavioral disorders.
Collapse
Affiliation(s)
- Nicole M Vittoz
- Psychology Department, University of Wisconsin, Madison, WI 53706, USA
| | | | | |
Collapse
|
11
|
Alvira-Botero MX, Garzón M. Cellular and subcellular distributions of delta opioid receptor activation sites in the ventral oral pontine tegmentum of the cat. Brain Res 2006; 1123:101-11. [PMID: 17045971 DOI: 10.1016/j.brainres.2006.09.030] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2006] [Revised: 09/11/2006] [Accepted: 09/12/2006] [Indexed: 10/23/2022]
Abstract
The ventral division of the reticular oral pontine nucleus (vRPO) is a pontine tegmentum region critically involved in REM sleep generation. Previous reports of morphine microinjections in the cat pontine tegmentum have shown that opioid receptor activation in this region modulates REM sleep. Even though opiate administration has marked effects on sleep-wake cycle architecture, the distribution of opioid receptors in vRPO has only been partially described. Using an antiserum directed against delta opioid receptor (DOR), to which morphine binds, in the present study, we use (1) light microscopy to determine DOR cellular distribution in the rostral pontine tegmentum and (2) electron microscopy to determine DOR subcellular distribution in the cat vRPO. In the dorsal pons, DOR immunoreactivity was evenly distributed throughout the neuropil of the reticular formation and was particularly intense in the parabrachial nuclei and locus coeruleus; the ventral and central areas of the RPO and locus coeruleus complex were especially rich in DOR-labeled somata. Within the vRPO, DOR was localized mainly in the cytoplasm and on plasma membranes of medium to large dendrites (47.8% of DOR-labeled profiles), which received both symmetric and asymmetric synaptic contacts mainly from non-labeled (82% of total inputs) axon terminals. Less frequently, DOR was distributed presynaptically in axon terminals (19% of DOR-labeled profiles). Our results suggest that DOR activation in vRPO regulates REM sleep occurrence by modulating postsynaptic responses to both excitatory and inhibitory afferents. DOR activation in vRPO could have, however, an additional role in direct modulation of neurotransmitter release from axon terminals.
Collapse
Affiliation(s)
- Maria Ximena Alvira-Botero
- Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de Madrid, Calle Arzobispo Morcillo 4, 28029, Madrid, Spain
| | | |
Collapse
|
12
|
Vittoz NM, Berridge CW. Hypocretin/orexin selectively increases dopamine efflux within the prefrontal cortex: involvement of the ventral tegmental area. Neuropsychopharmacology 2006; 31:384-95. [PMID: 15988471 DOI: 10.1038/sj.npp.1300807] [Citation(s) in RCA: 142] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Hypocretins (HCRTs) modulate a variety of behavioral and physiological processes, in part via interactions with multiple ascending modulatory systems. Further, HCRT efferents from the lateral hypothalamus innervate midbrain dopamine (DA) nuclei, and DA cell bodies express HCRT receptors. Combined, these observations suggest that HCRT may influence behavioral state and/or state-dependent processes via modulation of DA neurotransmission. The current studies used in vivo microdialysis in the unanesthetized rat to first characterize the effect of intracerebroventricular infusion of HCRT-1 (0.07, 0.7 nmol) on extracellular levels of DA within the prefrontal cortex (PFC) and nucleus accumbens (Acc). Electroencephalographic/electromyographic measures of sleep-wake state were collected along with select behavioral measures (eg locomotor activity, grooming). HCRT-1 dose-dependently increased PFC dialysate DA levels, and these increases were closely correlated with increases in time spent awake. In contrast, Acc DA levels were unaffected. Additional studies examined whether HCRT-1 acts directly within the ventral tegmental area (VTA) to selectively increase PFC DA efflux and modulate behavioral state. Unilateral infusion of HCRT-1 (0.1, 1.0 nmol) within the VTA increased PFC, but not Acc, DA levels. Importantly, intra-VTA infusion of HCRT-1 increased the time spent awake and grooming. Moreover, HCRT-induced increases in both time spent awake and time spent grooming were significantly correlated with post-infusion PFC DA levels. The current observations predict a prominent modulatory influence of HCRT on PFC-dependent cognitive and affective processes that results, in part, from actions within the VTA. Additionally, these observations suggest that the activation of VTA DA neurons contributes to the behavioral state-modulatory actions of HCRT.
Collapse
Affiliation(s)
- Nicole M Vittoz
- Department of Psychology, University of Wisconsin, Madison, 53706, USA
| | | |
Collapse
|
13
|
Abstract
This paper is the 27th consecutive installment of the annual review of research concerning the endogenous opioid system, now spanning over 30 years of research. It summarizes papers published during 2004 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia; stress and social status; tolerance and dependence; learning and memory; eating and drinking; alcohol and drugs of abuse; sexual activity and hormones, pregnancy, development and endocrinology; mental illness and mood; seizures and neurologic disorders; electrical-related activity and neurophysiology; general activity and locomotion; gastrointestinal, renal and hepatic functions; cardiovascular responses; respiration and thermoregulation; and immunological responses.
Collapse
Affiliation(s)
- Richard J Bodnar
- Department of Psychology and Neuropsychology Doctoral Sub-Program, Queens College, City University of New York, Flushing, NY 11367, USA.
| | | |
Collapse
|
14
|
|