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Urushihata T, Goto M, Kabetani K, Kiyozuka M, Maruyama S, Tsuji S, Tada H, Satoh A. Evaluation of cellular activity in response to sleep deprivation by a comprehensive analysis of the whole mouse brain. Front Neurosci 2023; 17:1252689. [PMID: 37928729 PMCID: PMC10620513 DOI: 10.3389/fnins.2023.1252689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Accepted: 09/12/2023] [Indexed: 11/07/2023] Open
Abstract
Sleep deprivation (SD) causes several adverse functional outcomes, and understanding the associated processes can improve quality of life. Although the effects of SD on neuronal activity in several brain regions have been identified, a comprehensive evaluation of the whole brain is still lacking. Hence, we performed SD using two different methods, gentle handling and a dedicated chamber, in targeted recombination in active populations 2 (TRAP2) mice crossed with Rosa-ZsGreen reporter mice and visualized cellular activity in the whole brain. Using the semi-automated post-imaging analysis tool Slice Histology Alignment, Registration, and Cell Quantification (SHARCQ), the number of activated cells was quantified. From the analysis of 14 brain regions, cellular activity was significantly increased in the olfactory areas and decreased in the medulla by the two SD methods. From the analysis of the further subdivided 348 regions, cellular activity was significantly increased in the vascular organ of the lamina terminalis, lateral hypothalamic area, parabigeminal nucleus, ventral tegmental area, and magnocellular reticular nucleus, and decreased in the anterior part of the basolateral amygdalar nucleus, nucleus accumbens, septohippocampal nucleus, reticular nucleus of the thalamus, preoptic part of the periventricular hypothalamic nucleus, ventromedial preoptic nucleus, rostral linear nucleus raphe, facial motor nucleus, vestibular nuclei, and some fiber tracts (oculomotor nerve, genu of corpus callosum, and rubrospinal tract) by the two SD methods. Two subdivided regions of the striatum (caudoputamen and other striatum), epithalamus, vascular organ of the lamina terminalis, anteroventral preoptic nucleus, superior colliculus optic layer, medial terminal nucleus of the accessory optic tract, pontine gray, and fiber tracts (medial lemniscus, columns of the fornix, brachium of the inferior colliculus, and mammillary peduncle) were differentially affected by the two SD methods. Most brain regions detected from these analyses have been reported to be involved in regulating sleep/wake regulatory circuits. Moreover, the results from the connectivity analysis indicated that the connectivity of cellular activity among brain regions was altered by SD. Together, such a comprehensive analysis of the whole brain is useful for understanding the mechanisms by which SD and/or sleep disruption affects brain function.
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Affiliation(s)
- Takuya Urushihata
- Department of Integrative Physiology, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
- Department of Integrative Physiology, National Center for Geriatrics and Gerontology, Obu, Japan
| | - Mio Goto
- Department of Integrative Physiology, National Center for Geriatrics and Gerontology, Obu, Japan
| | - Keiko Kabetani
- Department of Integrative Physiology, National Center for Geriatrics and Gerontology, Obu, Japan
| | - Mai Kiyozuka
- Department of Integrative Physiology, National Center for Geriatrics and Gerontology, Obu, Japan
- Department of Nutrition, Faculty of Wellness, Shigakkan University, Obu, Japan
| | - Shiho Maruyama
- Department of Integrative Physiology, National Center for Geriatrics and Gerontology, Obu, Japan
- Department of Nutrition, Faculty of Wellness, Shigakkan University, Obu, Japan
| | - Shogo Tsuji
- Department of Integrative Physiology, National Center for Geriatrics and Gerontology, Obu, Japan
| | - Hirobumi Tada
- Department of Integrative Physiology, National Center for Geriatrics and Gerontology, Obu, Japan
- Department of Nutrition, Faculty of Wellness, Shigakkan University, Obu, Japan
- Department of Physiology, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Akiko Satoh
- Department of Integrative Physiology, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
- Department of Integrative Physiology, National Center for Geriatrics and Gerontology, Obu, Japan
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Tschumi CW, Beckstead MJ. Neurotensin speeds inhibition of dopamine neurons through temporal modulation of GABA A and GABA B receptor-mediated synaptic input. Neuropharmacology 2018; 131:414-423. [PMID: 29307543 DOI: 10.1016/j.neuropharm.2018.01.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 12/02/2017] [Accepted: 01/02/2018] [Indexed: 01/20/2023]
Abstract
Midbrain dopamine neurons play physiological roles in many processes including reward learning and motivated behavior, and are tonically inhibited by γ-aminobutyric acid (GABA)ergic input from multiple brain regions. Neurotensin (NT) is a neuropeptide which acutely modulates midbrain dopamine neuron excitability through multiple mechanisms, one of which is a decrease of GABA-mediated inhibition. However, the mechanisms through which NT depresses GABA signaling are not known. Here we used whole cell patch-clamp electrophysiology of dopamine neurons in mouse brain slices to show that NT acts both presynaptically to increase GABAA and postsynaptically to decrease GABAB receptor-mediated currents in the substantia nigra. The active peptide fragment NT8-13 enhanced GABAA signaling presynaptically by causing an increase in the size of the readily releasable pool of GABA via activation of the NT type-1 receptor and protein kinase A. Conversely, NT8-13 depressed GABAB signaling postsynaptically via the NT type-2 receptor in a process that was modulated by protein kinase C. Both forms of plasticity could be observed simultaneously in single dopamine neurons. Thus, as the kinetics of GABAA signaling are significantly faster than those of GABAB signaling, NT functionally speeds GABAergic input to midbrain dopamine neurons. This finding contributes to our understanding of how neuropeptide-induced plasticity can simultaneously differentiate and integrate signaling by a single neurotransmitter in a single cell and provides a basis for understanding how neuropeptides use temporal shifts in synaptic strength to encode information.
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Affiliation(s)
- Christopher W Tschumi
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, 73104-5005, USA; Department of Cellular and Integrative Physiology, University of Texas Health, San Antonio, San Antonio, TX, 78229, USA
| | - Michael J Beckstead
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, 73104-5005, USA; Department of Cellular and Integrative Physiology, University of Texas Health, San Antonio, San Antonio, TX, 78229, USA.
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Carey LM, Rice RJ, Prus AJ. The Neurotensin NTS 1 Receptor Agonist PD149163 Produces Antidepressant-Like Effects in the Forced Swim Test: Further Support for Neurotensin as a Novel Pharmacologic Strategy for Antidepressant Drugs. Drug Dev Res 2017; 78:196-202. [PMID: 28736839 DOI: 10.1002/ddr.21393] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 06/11/2017] [Indexed: 11/09/2022]
Abstract
Preclinical Research Neurotensin is a nonbrain penetrant neuropeptide neurotransmitter that alters dopaminergic and serotonergic neurotransmission. Previous animal behavioral studies have demonstrated that intra-ventral tegmental administration of neurotensin and system administration of the selective neurotensin NTS1 receptor agonist, PD149163 produce antidepressant-like effects in a forced swim test and a differential reinforcement of low rate task, respectively. The present study sought to expand upon these past findings by assessing systemic administration of PD149163 in a forced swim test, a primary antidepressant preclinical screening model, in mice. The tricyclic antidepressant drug imipramine was tested for comparison, and both compounds were also assessed in an open field test. Both PD149163 and imipramine reduced time spent immobile, an antidepressant-like effect, in the forced swim test. The highest dose of each compound significantly reduced locomotor activity. These findings provide further evidence for the putative antidepressant effects for PD149163 and suggest that NTS1 receptor activation may be a novel pharmacologic strategy for antidepressant drug development. Drug Dev Res 78 : 196-202, 2017. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Lawrence M Carey
- Department of Psychological Science, Northern Michigan University, Marquette, MI, 49855
| | - Remington J Rice
- Department of Psychological Science, Northern Michigan University, Marquette, MI, 49855
| | - Adam J Prus
- Department of Psychological Science, Northern Michigan University, Marquette, MI, 49855
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Huber S, Casagrande F, Hug MN, Wang L, Heine P, Kummer L, Plückthun A, Hennig M. SPR-based fragment screening with neurotensin receptor 1 generates novel small molecule ligands. PLoS One 2017; 12:e0175842. [PMID: 28510609 PMCID: PMC5433701 DOI: 10.1371/journal.pone.0175842] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 04/01/2017] [Indexed: 12/22/2022] Open
Abstract
The neurotensin receptor 1 represents an important drug target involved in various diseases of the central nervous system. So far, the full exploitation of potential therapeutic activities has been compromised by the lack of compounds with favorable physicochemical and pharmacokinetic properties which efficiently penetrate the blood-brain barrier. Recent progress in the generation of stabilized variants of solubilized neurotensin receptor 1 and its subsequent purification and successful structure determination presents a solid starting point to apply the approach of fragment-based screening to extend the chemical space of known neurotensin receptor 1 ligands. In this report, surface plasmon resonance was used as primary method to screen 6369 compounds. Thereby 44 hits were identified and confirmed in competition as well as dose-response experiments. Furthermore, 4 out of 8 selected hits were validated using nuclear magnetic resonance spectroscopy as orthogonal biophysical method. Computational analysis of the compound structures, taking the known crystal structure of the endogenous peptide agonist into consideration, gave insight into the potential fragment-binding location and interactions and inspires chemistry efforts for further exploration of the fragments.
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Affiliation(s)
- Sylwia Huber
- Roche Innovation Center Basel, Pharmaceutical Research and Early Development, Basel, Switzerland
- * E-mail: (SH); (MH)
| | - Fabio Casagrande
- Roche Innovation Center Basel, Pharmaceutical Research and Early Development, Basel, Switzerland
| | - Melanie N. Hug
- Roche Innovation Center Basel, Pharmaceutical Research and Early Development, Basel, Switzerland
| | - Lisha Wang
- Roche Innovation Center Basel, Pharmaceutical Research and Early Development, Basel, Switzerland
| | - Philipp Heine
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Lutz Kummer
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Andreas Plückthun
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Michael Hennig
- Roche Innovation Center Basel, Pharmaceutical Research and Early Development, Basel, Switzerland
- * E-mail: (SH); (MH)
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Sánchez ML, Vecino E, Coveñas R. Distribution of Neurotensin and Somatostatin-28 (1-12) in the Minipig Brainstem. Anat Histol Embryol 2015; 45:260-76. [PMID: 26250798 DOI: 10.1111/ahe.12194] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 07/05/2015] [Indexed: 11/29/2022]
Abstract
Using an indirect immunoperoxidase technique, an in depth study has been carried out for the first time on the distribution of fibres and cell bodies containing neurotensin and somatostatin-28 (1-12) (SOM) in the minipig brainstem. The animals used were not treated with colchicine. The distribution of neurotensin- and SOM-immunoreactive fibres was seen to be quite similar and was moderate in the minipig brainstem: a close anatomical relationship between both neuropeptides was observed. The distribution of cell bodies containing neurotensin or SOM was quite different and restricted. Cell bodies containing neurotensin were found in four brainstem nuclei: nucleus centralis raphae, nucleus dorsalis raphae, in the pars centralis of the nucleus tractus spinalis nervi trigemini and in the nucleus ventralis raphae. Cell bodies containing SOM were found in six nuclei/regions of the brainstem: nucleus ambiguus, nucleus dorsalis motorius nervi vagus, formatio reticularis, nucleus parabrachialis medialis, nucleus reticularis lateralis and nucleus ventralis raphae. According to the observed anatomical distribution of the immunoreactive structures containing neurotensin or SOM, the peptides could be involved in sleep-waking, nociceptive, gustatory, motor, respiratory and autonomic mechanisms.
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Affiliation(s)
- M L Sánchez
- Laboratory of Neuroanatomy of the Peptidergic Systems, Institute of Neurosciences of Castilla y León (INCYL), University of Salamanca, c/Pintor Fernando Gallego, 1, 37007, Salamanca, Spain
| | - E Vecino
- Department of Cell Biology and Histology, University of the Basque Country, UPV/EHU, 48940, Leioa, Spain
| | - R Coveñas
- Laboratory of Neuroanatomy of the Peptidergic Systems, Institute of Neurosciences of Castilla y León (INCYL), University of Salamanca, c/Pintor Fernando Gallego, 1, 37007, Salamanca, Spain
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Prus AJ, Hillhouse TM, LaCrosse AL. Acute, but not repeated, administration of the neurotensin NTS1 receptor agonist PD149163 decreases conditioned footshock-induced ultrasonic vocalizations in rats. Prog Neuropsychopharmacol Biol Psychiatry 2014; 49:78-84. [PMID: 24275076 PMCID: PMC3923471 DOI: 10.1016/j.pnpbp.2013.11.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Revised: 11/15/2013] [Accepted: 11/18/2013] [Indexed: 12/11/2022]
Abstract
Neurotensin is an endogenous neuropeptide that has significant interactions with monoamine neurotransmitter systems. To date, neurotensin NTS1 receptor agonists, such as PD149163, have been primarily evaluated for the treatment for schizophrenia, drug addiction, and pain. Recently, PD149163 was found to attenuate fear-potentiated startle in rats, an experimental procedure used for screening anxiolytic drugs. The present study sought to assess these findings through testing PD149163 in a conditioned footshock-induced ultrasonic vocalization (USV) model. Conditioning was conducted in male Wistar rats using chambers equipped with shock grid floors and an ultrasonic vocalization detector. PD149163 and the 5-HT1A receptor partial agonist buspirone produced a statistically significant reduction of 22kHz USV counts. The typical antipsychotic haloperidol also reduced 22kHz USV counts, but did so at cataleptic doses. Ten days of repeated administration of PD149163 abolished the inhibitory effects of PD149163 on 22kHz USVs. These findings further support an anxiolytic profile for PD149163. However, tolerance to these effects may limit the utility of these drugs for the treatment of anxiety.
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Affiliation(s)
- Adam J. Prus
- Psychology Department, Northern Michigan University, Marquette, MI USA,Corresponding author, Adam J. Prus, Ph.D., Associate Professor, Psychology Department, Northern Michigan University, 1401 Presque Isle Ave., Marquette, MI 49855 USA, , Phone: 906-227-2941, Fax: 906-227-2954
| | - Todd M. Hillhouse
- Department of Psychology, Virginia Commonwealth University, Richmond VA, USA
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Zhang Y, Zhu S, Yi L, Liu Y, Cui H. Neurotensin receptor1 antagonist SR48692 reduces proliferation by inducing apoptosis and cell cycle arrest in melanoma cells. Mol Cell Biochem 2013; 389:1-8. [DOI: 10.1007/s11010-013-1920-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Accepted: 12/06/2013] [Indexed: 11/24/2022]
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8
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Boules M, Li Z, Smith K, Fredrickson P, Richelson E. Diverse roles of neurotensin agonists in the central nervous system. Front Endocrinol (Lausanne) 2013; 4:36. [PMID: 23526754 PMCID: PMC3605594 DOI: 10.3389/fendo.2013.00036] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Accepted: 03/06/2013] [Indexed: 01/10/2023] Open
Abstract
Neurotensin (NT) is a tridecapeptide that is found in the central nervous system (CNS) and the gastrointestinal tract. NT behaves as a neurotransmitter in the brain and as a hormone in the gut. Additionally, NT acts as a neuromodulator to several neurotransmitter systems including dopaminergic, sertonergic, GABAergic, glutamatergic, and cholinergic systems. Due to its association with such a wide variety of neurotransmitters, NT has been implicated in the pathophysiology of several CNS disorders such as schizophrenia, drug abuse, Parkinson's disease (PD), pain, central control of blood pressure, eating disorders, as well as, cancer and inflammation. The present review will focus on the role that NT and its analogs play in schizophrenia, endocrine function, pain, psychostimulant abuse, and PD.
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Affiliation(s)
- Mona Boules
- Neuropsychopharmacology Laboratory, Department of Neuroscience, Mayo Clinic FloridaJacksonville, FL, USA
- *Correspondence: Mona Boules, Neuropsychopharmacology Laboratory, Department of Neuroscience, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL 32224, USA. e-mail:
| | - Zhimin Li
- Neuropsychopharmacology Laboratory, Department of Neuroscience, Mayo Clinic FloridaJacksonville, FL, USA
| | - Kristin Smith
- Neuropsychopharmacology Laboratory, Department of Neuroscience, Mayo Clinic FloridaJacksonville, FL, USA
| | - Paul Fredrickson
- Neuropsychopharmacology Laboratory, Department of Neuroscience, Mayo Clinic FloridaJacksonville, FL, USA
| | - Elliott Richelson
- Neuropsychopharmacology Laboratory, Department of Neuroscience, Mayo Clinic FloridaJacksonville, FL, USA
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9
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Holly EN, Ebrecht B, Prus AJ. The neurotensin-1 receptor agonist PD149163 inhibits conditioned avoidance responding without producing catalepsy in rats. Eur Neuropsychopharmacol 2011; 21:526-31. [PMID: 21277173 PMCID: PMC3110992 DOI: 10.1016/j.euroneuro.2010.12.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2010] [Revised: 10/27/2010] [Accepted: 12/18/2010] [Indexed: 12/12/2022]
Abstract
Agonists for neurotensin (NT)-1 receptors have produced antipsychotic-like effects in many animals, including reversal of prepulse inhibition deficits and psychostimulant-induced increases in spontaneous activity. The present study sought to provide a basic assessment of the putative antipsychotic effects of PD149163 in rats using a two way conditioned avoidance response task, which is highly validated for screening antipsychotic drugs, and an inclined grid assessment, which is used to assess extrapyramidal side effect liability. PD149163 (0.0625-8.0 mg/kg) significantly suppressed conditioned avoidance responding (CAR) following administration of a 1.0 or 8.0 mg/kg dose. PD149163 failed to significantly increase catalepsy scores. The typical antipsychotic drug haloperidol (0.01-1.0 mg/kg) significantly suppressed CAR at a 0.1, 0.3, and 1.0 mg/kg dose, and a significant increase in catalepsy scores was found at the 1.0 mg/kg dose. The atypical antipsychotic drug clozapine (2.5-10.0 mg/kg) also produced a significant inhibition of CAR, which occurred following administration of a 10.0 mg/kg dose. Clozapine failed to significantly increase catalepsy scores. Finally, D-amphetamine (1.0 mg/kg), serving as a negative control, failed to suppress CAR or increase catalepsy scores. These data further suggest that PD149163 may have atypical antipsychotic-like properties.
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Affiliation(s)
- Elizabeth N Holly
- Psychology Department, Northern Michigan University, 1401 Presque Isle Ave., Marquette, Michigan, USA
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10
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Functional organization of the dorsal raphe efferent system with special consideration of nitrergic cell groups. J Chem Neuroanat 2011; 41:281-93. [PMID: 21640185 DOI: 10.1016/j.jchemneu.2011.05.008] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2011] [Revised: 05/10/2011] [Accepted: 05/16/2011] [Indexed: 11/22/2022]
Abstract
The serotonin (5HT) system of the brain is involved in many CNS functions including sensory perception, stress responses and psychological disorders such as anxiety and depression. Of the nine 5HT nuclei located in the mammalian brain, the dorsal raphe nucleus (DRN) has the most extensive forebrain connectivity and is implicated in the manifestation of stress-related psychological disturbances. Initial investigations of DRN efferent connections failed to acknowledge the rostrocaudal and mediolateral organization of the nucleus or its neurochemical heterogeneity. More recent studies have focused on the non-5HT contingent of DRN cells and have revealed an intrinsic intranuclear organization of the DRN which has specific implications for sensory signal processing and stress responses. Of particular interest are spatially segregated subsets of nitric oxide producing neurons that are activated by stressors and that have unique efferent projection fields. In this regard, both the midline and lateral wing subregions of the DRN have emerged as prominent loci for future investigation of nitric oxide function and modulation of sensory- and stressor-related signals in the DRN and coinciding terminal fields.
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Briody S, Boules M, Oliveros A, Fauq I, Richelson E. Chronic NT69L potently prevents drug-induced disruption of prepulse inhibition without causing tolerance. Behav Brain Res 2010; 207:118-24. [PMID: 19800922 PMCID: PMC2788020 DOI: 10.1016/j.bbr.2009.09.044] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2009] [Revised: 09/23/2009] [Accepted: 09/27/2009] [Indexed: 12/26/2022]
Abstract
NT69L is a neurotensin receptor agonist with antipsychotic-like activity. NT69L blocks apomorphine-induced climbing in rats with no effect on stereotypic behavior, attenuates d-amphetamine-induced hyperactivity, and blocks pharmacologically induced disruption of prepulse inhibition (PPI) of the startle response. Repeated administration of NT69L results in tolerance to some, but not to all of its effects. Because schizophrenic patients require long-term treatment, chronic (21-day) administration of NT69L was tested in PPI with comparisons to chronic haloperidol and clozapine treatment. Sprague-Dawley rats received acute or 21 daily, subcutaneous injections of NT69L (1.0mg/kg). On days 1 and 21 the NT69L injection was followed 30 min later by treatment with either saline; the dopamine agonist, d-amphetamine (5.0mg/kg); or the serotonin 5-HT(2A) psychotomimetic receptor agonist [1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane] DOI (0.5mg/kg). Experiments were repeated with either haloperidol (1mg/kg) or clozapine (20mg/kg) in place of NT69L. Acute injection of NT69L significantly blocked d-amphetamine and DOI disruption of PPI. As with the acute injection, 21 daily administrations of NT69L also blocked d-amphetamine- and DOI-induced disruption of PPI. The data show that animals do not develop tolerance to the antipsychotic-like effects of NT69L when tested in the PPI of the startle response. The persistent efficacy of NT69L with chronic treatment provides further support for the therapeutic use of neurotensin (NT) agonists to treat schizophrenia and possibly other disorders that are characterized by PPI deficits. The modulatory role of NT69L on the dopaminergic and serotonergic neurotransmission systems both of which are implicated in the pathophysiology of schizophrenia is discussed.
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Affiliation(s)
| | - Mona Boules
- Corresponding author Mayo Clinic 4500 San Pablo Rd Jacksonville, FL 32224 Tel: (904)953-7136 Fax: (904)953-7117
| | - Alfredo Oliveros
- Neuropsychopharmacology Laboratory, Mayo Foundation for Medical Education and Research
| | - Irfan Fauq
- Neuropsychopharmacology Laboratory, Mayo Foundation for Medical Education and Research
| | - Elliott Richelson
- Neuropsychopharmacology Laboratory, Mayo Foundation for Medical Education and Research
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NT79: A novel neurotensin analog with selective behavioral effects. Brain Res 2009; 1308:35-46. [PMID: 19874804 DOI: 10.1016/j.brainres.2009.10.050] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2009] [Revised: 10/08/2009] [Accepted: 10/17/2009] [Indexed: 11/21/2022]
Abstract
Neurotensin, a tridecapeptide, is widely distributed in the brain and gastrointestinal tract. It possesses analgesic, hypothermic, and antipsychotic-like properties. Neurotensin's effects are mediated mainly through two receptor subtypes, NTS1 and NTS2. Activation of NTS1 has been implicated in most of the pharmacological effects of neurotensin but is associated with hypothermia and hypotension. We report on a novel neurotensin analog with higher selectivity to NTS2, namely, NT79, which exhibits selective behavioral effects. NT79 was tested in animal models for pain (thermal-hot plate test; visceral-acetic acid-induced writhing test), and in animal models that are predictive of antipsychotic-like effects (apomorphine-induced climbing; d-amphetamine-induced hyperactivity; disruption of prepulse inhibition). Its effects on body temperature and on blood pressure were also determined. Neurochemical changes in extracellular neurotransmitters were measured using in vivo microdialysis while the rats were simultaneously evaluated for acetic acid-induced writhing with and without pretreatment with NT79. Binding data at molecularly cloned hNTS1 and hNTS2 suggest selectivity for hNTS2. NT79 blocked the acetic acid-induced writhing with an ED(50) of 0.14 microg/kg while having no effect on thermal nociception. The writhing was paralleled by an increase in 5-HT which was attenuated by NT79. NT79 demonstrated antipsychotic-like effects by blocking apomorphine-induced climbing, d-amphetamine-induced hyperactivity, and reducing d-amphetamine- and DOI-induced disruption of prepulse inhibition. Uniquely, it caused no significant hypothermia and was without effect on blood pressure. NT79, with its higher selectivity to NTS2, may be potentially useful to treat visceral pain, and psychosis without concomitant side effects of hypothermia or hypotension.
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Lagos P, Torterolo P, Jantos H, Chase MH, Monti JM. Effects on sleep of melanin-concentrating hormone (MCH) microinjections into the dorsal raphe nucleus. Brain Res 2009; 1265:103-10. [DOI: 10.1016/j.brainres.2009.02.010] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2008] [Revised: 01/14/2009] [Accepted: 02/04/2009] [Indexed: 11/27/2022]
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Petkova-Kirova P, Rakovska A, Zaekova G, Ballini C, Corte LD, Radomirov R, Vágvölgyi A. Stimulation by neurotensin of dopamine and 5-hydroxytryptamine (5-HT) release from rat prefrontal cortex: possible role of NTR1 receptors in neuropsychiatric disorders. Neurochem Int 2008; 53:355-61. [PMID: 18835308 DOI: 10.1016/j.neuint.2008.08.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2008] [Revised: 08/08/2008] [Accepted: 08/08/2008] [Indexed: 10/21/2022]
Abstract
The modulation of cortical dopaminergic and serotonergic neurotransmissions by neurotensin (NT) was studied by measuring the release of dopamine (DA) and 5-hydroxytryptamine (5-HT) from the prefrontal cortex (PFC) of freely moving rats. The samples were collected via transversal microdialysis. Dopamine and 5-HT levels in the dialysate were measured using high-performance liquid chromatography (HPLC) with an electrochemical detector. Local administration of neurotensin (1microM or 0.1microM) in the PFC via the dialysis probe produced significant, long-lasting, and concentration-dependent increase in the extracellular release of DA and 5-HT. The increase produced by 1microM neurotensin reached a maximum of about 210% for DA and 340% for 5-HT. A high-affinity selective neurotensin receptor (NTR1) antagonist {2-[(1-(7-chloro-4-quinolinyl)-5-(2,6-dimethoxyphenyl)pyrazol-3yl)carbonylamino tricyclo (3.3.1.1.(3.7)) decan-2-carboxylic acid} (SR 48692), perfused locally at a concentration of 0.1microM and 0.5microM in the PFC antagonized the effects of 1microM neurotensin. Our in vivo neurochemical results indicate, for the first time, that neurotensin is able to regulate cortical dopaminergic and serotonergic neuronal activity in freely moving rats. These effects are possibly mediated by interactions of neurotensin with neurons releasing DA or 5-HT, projecting to the PFC from the ventrotegmental area (VTA) and from the dorsal raphe nuclei (DRN), respectively. The potentiating effects of neurotensin on DA and 5-HT release in the PFC are regulated by NTR1 receptors, probably located on dopaminergic and serotonergic nerve terminals or axons.
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Affiliation(s)
- Polina Petkova-Kirova
- Institute of Biophysics, Bulgarian Academy of Sciences, Acad. G. Bonchev Street bl. 21, 1113 Sofia, Bulgaria
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Serotoninergic mechanisms of the effects of neurotensin on passive avoidance behavior in rats. ACTA ACUST UNITED AC 2008; 38:517-21. [PMID: 18607747 DOI: 10.1007/s11055-008-9011-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2006] [Accepted: 03/12/2007] [Indexed: 10/21/2022]
Abstract
The aim of the present work was to identify the features of the actions of neurotensin on administration into the substantia nigra or dorsal cervical nucleus on the reproduction of passive avoidance reactions in rats. The results showed that the action of neurotensin administered into the substantia nigra was accompanied by sharp reductions in passive avoidance reactions, while administration into the dorsal cervical nucleus, conversely, led to increases in these reactions and slowing of their extinction. The effects of microinjections of the serotonin 5-HT(1A) receptor agonist 8-hydroxydipropylaminotetraline (8-OH-DPAT) into these brain structures were analogous to the effects of neurotensin. The different behavioral effects of administration of neurotensin corresponded to identifiable changes in the levels of serotonin and its metabolite 5-hydroxyindoleacetic acid in the caudate nuclei of the brain. These data led to the conclusion that the effects of neurotensin on passive avoidance behavior are associated with the regulation of the emotional state of the animals via actions on the functions of brain serotoninergic structures.
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16
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Monti JM, Jantos H. Activation of the serotonin 5-HT3 receptor in the dorsal raphe nucleus suppresses REM sleep in the rat. Prog Neuropsychopharmacol Biol Psychiatry 2008; 32:940-7. [PMID: 18295951 DOI: 10.1016/j.pnpbp.2007.12.024] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2007] [Revised: 12/19/2007] [Accepted: 12/26/2007] [Indexed: 11/24/2022]
Abstract
The effects of the selective 5-HT(3) receptor agonist and antagonist m-chlorophenylbiguanide (m-CPBG) and ondansetron, respectively, were studied in adult male Wistar rats implanted for chronic sleep recordings. Microinjection of m-CPBG (2.0 and 4.0 mM) into the dorsal raphe nucleus (DRN) decreased rapid-eye-movement sleep (REMS) and the number of REM periods during the first, second, and third 2-h recording period. On the other hand, direct infusion of ondansetron (0.5-1.0 mM) into the DRN induced no significant changes in sleep variables over the 6 h of recording. Pretreatment with ondansetron (0.5 mM) antagonized the m-CPBG (2.0 mM)-induced reduction of REMS and of the number of REM periods. The data are consistent with the hypothesis that the 5-HT(3) receptor is involved in the effect of DRN serotonergic neurons on brainstem structures that act to promote and induce REMS. It is suggested that the suppression of REMS after the microinjection of m-CPBG into the DRN is related, at least in part, to the stimulation of glutamatergic interneurons that express 5-HT(3) receptors. Activation of these receptors facilitates the release of glutamate, which, in turn, acts on postsynaptic N-methyl-d-aspartate and non-N-methyl-d-aspartate receptors expressed by serotonergic neurons of the DRN and increases the release of 5-HT at postsynaptic sites.
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Affiliation(s)
- Jaime M Monti
- Department of Pharmacology and Therapeutics, School of Medicine, Clinics Hospital, Montevideo 11300, Uruguay.
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17
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Akash KG, Balarama KS, Paulose CS. Enhanced 5-HT(2A) receptor status in the hypothalamus and corpus striatum of ethanol-treated rats. Cell Mol Neurobiol 2008; 28:1017-25. [PMID: 18425575 DOI: 10.1007/s10571-008-9281-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2007] [Accepted: 03/27/2008] [Indexed: 10/22/2022]
Abstract
AIM Brain is the major target for the actions of ethanol and it can affect the brain in a variety of ways. In the present study we have investigated the changes in 5-HT level and the 5-HT(2A) receptors in the ethanol-treated rats. METHODS Wistar adult male rats of 180-200 g body weight were given free access to 15% (v/v) (approx.7.5 g/Kg body wt./day) ethanol for 15 days. Controls were given free access to water for 15 days. Brain 5-HT and its metabolites were assayed by high performance liquid chromatography (HPLC) integrated with an electrochemical detector (ECD) fitted with C-18-CLS-ODS reverse phase column. 5-HT(2A) receptor binding assay was done with different concentrations of [3H] MDL 100907. RESULTS The hypothalamic 5-HT content significantly increased (P < 0.001) with a decreased (P < 0.001) 5-HIAA/5-HT turnover in the ethanol-treated rats when compared to control. The corpus striatum 5-HT content significantly decreased (P < 0.01) with increased (P < 0.01) 5-HIAA/5- HT turnovers in the ethanol-treated rats when compared to control. Scatchard analysis of [(3)H] MDL 100907 against ketanserin in hypothalamus showed a significant increase (P < 0.001) in B(max )with a decreased affinity (P < 0.001) in ethanol-treated rats when compared to control. The competition curve for [3H] MDL 100907 against ketanserin fitted one-site model in all the groups with unity as Hill slope value. An increased K(i) and log (EC(50)) value were also observed in ethanol-treated rats when compared to control. Scatchard analysis of [3H] MDL 100907 against ketanserin in the corpus striatum of ethanol-treated rats showed a significant increase (P < 0.001) in B(max) and in affinity (P < 0.01) when compared to control. The change in affinity of the receptor protein in both corpus striatum and hypothalamus shows an altered receptor. The competition curve for [(3)H] MDL 100907 against ketanserin fitted one-site model in all the groups with unity as Hill slope value. There was no significant change in K(i) and log (EC (50)) value in ethanol-treated rats when compared to control. CONCLUSION The present study demonstrated the enhanced 5-HT(2A) receptor status in hypothalamus and corpus striatum. The ethanol-induced enhanced 5-HT(2A) receptors in the hypothalamus and corpus striatum has clinical significance in the better management of ethanol addiction. This will have therapeutic application.
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Affiliation(s)
- K G Akash
- Molecular neurobiology and Cell Biology Unit, Centre for Neuroscience, Department of Biotechnology, Cochin University of Science and Technology, Cochin, 682022 Kerala, India
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18
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Ivanov IS, Schulz KP, Palmero RC, Newcorn JH. Neurorobiology and evidence-based biological treatments for substance abuse disorders. CNS Spectr 2006; 11:864-77. [PMID: 17075558 DOI: 10.1017/s1092852900015017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Behavioral patterns of addiction include compulsive drug-seeking, persistent abuse of substances despite the often dire consequences on social functioning and physical health, and the high probability of relapse even after prolonged drug-free periods. The recent focus on the biological basis of addiction has provided evidence to support the hypothesis that behavioral manifestations for addiction are influenced by biological factors, and biological factors often produce behavioral changes that can further increase risk. The current understanding of the role of the dopaminergic, glutamatergic, Upsilon-aminobutyric acidergic, and opioid receptor systems in the pathophysiology of addiction as well as the clinical implications of these systems for new and emerging treatments will be discussed. This article will also review the pharmacologic agents used in the treatment of substance abuse disorders and presents evidence-based data for their safety, efficacy, and feasibility of use in different patient populations.
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Affiliation(s)
- Iliyan S Ivanov
- Department of Psychiatry, Mount Sinai School of Medicine, New York, NY 10029, USA.
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19
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Abstract
Neurotensin (NT) can produce a profound analgesia or enhance pain responses, depending on the circumstances. Recent evidence suggests that this may be due to a dose-dependent recruitment of distinct populations of pain modulatory neurons. NT knockout mice display defects in both basal nociceptive responses and stress-induced analgesia. Stress-induced antinociception is absent in these mice and instead stress induces a hyperalgesic response, suggesting that NT plays a key role in the stress-induced suppression of pain. Cold water swim stress results in increased NT mRNA expression in hypothalamic regions known to project to periaqueductal gray, a key region involved in pain modulation. Thus, stress-induced increases in NT signaling in pain modulatory regions may be responsible for the transition from pain facilitation to analgesia. This review focuses on recent advances that have provided insights into the role of NT in pain modulation.
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Affiliation(s)
- Paul R Dobner
- Department of Molecular Genetics and Microbiology, Program in Neuroscience, University of Massachusetts Medical School, 55 Lake Ave. North, Worcester, MA 01655, USA.
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20
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Gomide VC, de Francisco AC, Chadi G. Localization of neurotensin immunoreactivity in neurons and organ of corti of rat cochlea. Hear Res 2005; 205:1-6. [PMID: 15953510 DOI: 10.1016/j.heares.2005.02.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2004] [Accepted: 02/26/2005] [Indexed: 11/20/2022]
Abstract
The distribution of neurotensin-containing cell bodies and fibers has been observed in the central and peripheral nervous system, including sensory ganglia, but no description has been found in the peripheral auditory system. Here, we investigated the presence of neurotensin immunoreactivity in the cochlea of the adult Wistar rat. Strong neurotensin immunoreactivity was detected in the cytoplasm of the inner hair cells (IHC) and Deiters' cells of the organ of Corti. Outer hair cells (OHC) show weak immunoreaction. Neurotensin immunoreactivity was also found in the neurons and fibers of the spiral ganglia. Quantitative microdensitometric image analysis of the neurotensin immunoreactivity showed a strong immunoreaction in the hair cells of organ of Corti and a moderate to strong labeling in the spiral ganglion neurons. A series of double immunolabeling experiments demonstrated a strong neurotensin immunoreactivity in the parvalbumin immunoreactive IHC and also in the calbindin immunoreactive Deiters' cells. Weak neurotensin immunoreactivity was seen in the calbindin positive OHC. Neurofilament and parvalbumin immunoreactive neurons and fibers in the spiral ganglia showed neurotensin immunoreactivity. Calbindin immunoreactivity was not detected in the spiral ganglion neurons, which are labeled by neurotensin immunoreactivity. The presence of neurotensin in the cochlea may be related to its modulation of neurotransmission in the peripheral auditory pathway.
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Affiliation(s)
- Vânia C Gomide
- Laboratory of Neuroregeneration, Department of Anatomy, Institute of Biomedical Sciences, University of São Paulo, 05508-900 São Paulo, Brazil
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21
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Juszczak GR, Swiergiel AH. Serotonergic hypothesis of sleepwalking. Med Hypotheses 2005; 64:28-32. [PMID: 15533605 DOI: 10.1016/j.mehy.2004.06.013] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2004] [Accepted: 06/12/2004] [Indexed: 11/28/2022]
Abstract
Despite widespread prevalence of sleepwalking, its etiology and pathophysiology are not well understood. However, there is some evidence that sleepwalking can be precipitated by sleep-disordered breathing. A hypothesis is proposed that serotonergic system may be a link between sleep-disordered breathing and sleepwalking. Serotonergic neurons meet basic requirements for such a role because they are activated by hypercapnia, provide a tonic excitatory drive that gates afferent inputs to motoneurons, and the activity of serotonergic neurons can be dissociated from the level of arousal. This paper discusses also drug-induced somnambulism and co-occurrence of sleepwalking and other disorders such as migraine and febrile illness.
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Affiliation(s)
- Grzegorz R Juszczak
- Department of Animal Behavior, Institute of Genetics and Animal Breeding, Polish Academy of Sciences, Jastrzebiec, 05-552 Wolka Kosowska, Poland.
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22
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Shugalev NP, Khartmann G, Kertesh E. Aftereffects of microinjections of neurotensin into the substantia nigra of the brain on conditioned motor responses in rats with lesions to serotoninergic neurons. ACTA ACUST UNITED AC 2005; 35:147-51. [PMID: 15779326 DOI: 10.1007/s11055-005-0056-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The effects of neurotensin microinjections into the substantia nigra of the brain on the performance of motor reactions in response to positive (food reinforcement) and negative (unreinforced) conditioned signals were studied, along with the characteristic aftereffects of these microinjections in rats with lesions to serotoninergic neurons in the dorsal cervical nucleus. Lesions were produced by local administration of the selective neurotoxin 5,7-dihydroxytryptamine. Microinjections of neurotensin were found to weaken the disinhibitory effects of neurotoxin on extinction of intersignal responses and extinction of conditioned motor reactions in response to presentation of negative stimuli, but to have no marked effect on the performance of reactions evoked by positive conditioned signals. Changes persisted into subsequent experiments without peptide microinjections. Measurements of the level of preference of the animals for one quadrant of the experimental chamber showed that operated rats avoided occupying the test quadrant and preferred to locate themselves in the opposite quadrant. Neurotensin released this effect of the neurotoxin. These results lead to the conclusion that these behavioral effects of neurotensin are associated with its normalizing influences on the motivational-emotional state of the animals with lesions to serotoninergic neurons and may also be due to the formation in the animals of a contextual conditioned emotional state, which aids optimization of the adaptive functions of the brain.
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Affiliation(s)
- N P Shugalev
- Science Research Institute of the Brain, Russian Academy of Medical Sciences, Moscow.
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23
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Shilling PD, Melendez G, Priebe K, Richelson E, Feifel D. Neurotensin agonists block the prepulse inhibition deficits produced by a 5-HT2A and an alpha1 agonist. Psychopharmacology (Berl) 2004; 175:353-9. [PMID: 15107967 DOI: 10.1007/s00213-004-1835-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
RATIONALE Neurotensin (NT) agonists have been proposed as potential antipsychotics based exclusively upon their ability to inhibit dopamine-2 (D2) receptor transmission. Several other pharmacological mechanisms have been implicated in enhancing the antipsychotic profile produced by D2 inhibition alone. These include inhibition of 5-HT2A and alpha1-adrenoceptors. Recently, we reported that systemic administration of the neurotensin agonist PD149163 blocks deficits in prepulse inhibition (PPI) of the startle reflex produced by the 5-HT2A receptor agonist DOI. This suggested that NT agonists could inhibit 5-HT2A modulation of neurotransmission. OBJECTIVE To determine if other peripherally administered NT agonists shared this effect, we examined the effects of NT69L, another NT agonist, on DOI-induced PPI deficits. In addition, to determine if NT agonists also inhibit alpha1-adrenoceptor neurotransmission, we examined the effects of PD149163 and NT69L on PPI deficits induced by the alpha1-adrenoceptor agonist, cirazoline. METHODS In the NT69L/DOI study, rats received subcutaneous (SC) injections of NT69L (0, 0.1, 1, or 2 mg/kg) followed 30 min later by SC saline or DOI (0.5 mg/kg). In the NT agonist/cirazoline studies, animals received SC injections of either PD149163 (0, 0.01, 0.1, or 1 mg/kg) or NT69L (0, 0.01, 0.1, or 1 mg/kg) followed 30 min later by SC saline or cirazoline (0.7 mg/kg). Animals were tested in startle chambers 20 min later. RESULTS In all three experiments the PPI disruption produced by DOI and cirazoline was blocked by the NT agonists. CONCLUSIONS These findings provide strong evidence that NT agonists inhibit 5-HT2A and alpha1-adrenoceptor modulation of neurotransmission, pharmacological effects that, in conjunction with their known inhibition of dopamine transmission, strengthen the antipsychotic potential of NT agonists.
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Affiliation(s)
- P D Shilling
- Department of Psychiatry, University of California San Diego, La Jolla, CA 92093, USA
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24
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Kirby LG, Pernar L, Valentino RJ, Beck SG. Distinguishing characteristics of serotonin and non-serotonin-containing cells in the dorsal raphe nucleus: electrophysiological and immunohistochemical studies. Neuroscience 2003; 116:669-83. [PMID: 12573710 PMCID: PMC2832757 DOI: 10.1016/s0306-4522(02)00584-5] [Citation(s) in RCA: 153] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The membrane properties and receptor-mediated responses of rat dorsal raphe nucleus neurons were measured using intracellular recording techniques in a slice preparation. After each experiment, the recorded neuron was filled with neurobiotin and immunohistochemically identified as 5-hydroxytryptamine (5-HT)-immunopositive or 5-HT-immunonegative. The cellular characteristics of all recorded neurons conformed to previously determined classic properties of serotonergic dorsal raphe nucleus neurons: slow, rhythmic activity in spontaneously active cells, broad action potential and large afterhyperpolarization potential. Two electrophysiological characteristics were identified that distinguished 5-HT from non-5-HT-containing cells in this study. In 5-HT-immunopositive cells, the initial phase of the afterhyperpolarization potential was gradual (tau=7.3+/-1.9) and in 5-HT-immunonegative cells it was abrupt (tau=1.8+/-0.6). In addition, 5-HT-immunopositive cells had a shorter membrane time constant (tau=21.4+/-4.4) than 5-HT-immunonegative cells (tau=33.5+/-4.2). Interestingly, almost all recorded neurons were hyperpolarized in response to stimulation of the inhibitory 5-HT(1A) receptor. These results suggested that 5-HT(1A) receptors are present on non-5-HT as well as 5-HT neurons. This was confirmed by immunohistochemistry showing that although the majority of 5-HT-immunopositive cells in the dorsal raphe nucleus were double-labeled for 5-HT(1A) receptor-IR, a small but significant population of 5-HT-immunonegative cells expressed the 5-HT(1A) receptor. These results underscore the heterogeneous nature of the dorsal raphe nucleus and highlight two membrane properties that may better distinguish 5-HT from non-5-HT cells than those typically reported in the literature. In addition, these results present electrophysiological and anatomical evidence for the presence of 5-HT(1A) receptors on non-5-HT neurons in the dorsal raphe nucleus.
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Affiliation(s)
- L G Kirby
- Department of Pediatrics, Joseph Stokes Jr. Research Institute, Abramson Research Center, 4th Floor North, Children's Hospital of Philadelphia, Philadelphia, PA 19104-4318, USA.
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25
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Bárbara A, Aceves J, Arias-Montaño JA. Histamine H1 receptors in rat dorsal raphe nucleus: pharmacological characterisation and linking to increased neuronal activity. Brain Res 2002; 954:247-55. [PMID: 12414108 DOI: 10.1016/s0006-8993(02)03352-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
In this work we studied the presence of histamine H(1) receptors in the rat dorsal raphe nucleus (DRN) and the effect of their activation on the activity of presumed serotonergic DRN neurones. [(3)H]-Mepyramine bound to DRN membranes with best-fit values of 107+/-13 fmol/mg protein for maximum binding (B(max)) and 1.2+/-0.4 nM for the equilibrium dissociation constant (K(d)). In DRN slices labelled with [(3)H]-inositol and in the presence of 10 mM LiCl, histamine stimulated the accumulation of [(3)H]-inositol phosphates ([(3)H]-IPs) with maximum effect 172+/-6% of basal and EC(50) 3.2+/-1.3 microM. [(3)H]-IPs accumulation induced by 100 microM histamine (162+/-5% of basal) was markedly, but not fully blocked by the selective H(1) antagonist mepyramine (300 nM; 64+/-6% inhibition). The simultaneous addition of mepyramine and the selective H(2) antagonist ranitidine (10 microM) abolished histamine-induced [(3)H]-IPs accumulation. The presence of H(2) receptors was confirmed by [(3)H]-tiotidine binding and by the determination of histamine-induced [(3)H]-cyclic AMP formation. Extracellular single-unit recording in brain stem slices showed that the exposure to histamine resulted in a marked increase in the firing rate of DRN presumed serotonergic neurones (471+/-10% of basal), that was dependent on the concentration of the agonist (EC(50) 4.5+/-0.3 microM). The action of histamine was not affected by the H(2) antagonist tiotidine (2 microM) but was fully prevented by 1 microM mepyramine. Taken together, our results indicate that histamine modulates the firing of DRN presumed serotonergic neurones through the activation of H(1) receptors coupled to phosphonositide hydrolysis.
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Affiliation(s)
- Alfonso Bárbara
- Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados, Apdo postal 14-740, 07000 México, DF, Mexico
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26
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Corley KC, Phan TH, Daugherty WP, Boadle-Biber MC. Stress-induced activation of median raphe serotonergic neurons in rats is potentiated by the neurotensin antagonist, SR 48692. Neurosci Lett 2002; 319:1-4. [PMID: 11814639 DOI: 10.1016/s0304-3940(01)02414-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The activation of rostrally projecting serotonergic (5-HT) neurons by acute sound stress is blocked by exogenous administration of the tridecapeptide neurotensin (NT). 5-HT neurons respond to acute sound stress within the median raphe nucleus (MRN), but not within the dorsal raphe nucleus or hindbrain regions. By use of the NT antagonist, SR 48692, the present study examines the involvement of endogenous NT in modulating the preferential activation of MRN 5-HT neurons by sound stress, and extends the findings with sound stress to two other stressors (swim and tail shock). Activation is determined from the enhanced accumulation of 5-hydroxytryptophan (5-HTP) from various brain regions over basal after inhibition of aromatic amino acid decarboxylase. The NT antagonist, SR 48692, enhances the stress activation of MRN 5-HT neurons and its projections without changing 5-HTP accumulation under basal conditions. Thus, the antagonist, SR 48692, unmasks the action of endogenous NT-containing neurons indicating that they become activated by stress and serve to attenuate the stress-induced response of MRN 5-HT neurons.
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Affiliation(s)
- Karl C Corley
- Virginia Commonwealth University, Richmond, VA 23298, USA
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27
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Coogan AN, Rawlings N, Luckman SM, Piggins HD. Effects of neurotensin on discharge rates of rat suprachiasmatic nucleus neurons in vitro. Neuroscience 2001; 103:663-72. [PMID: 11274786 DOI: 10.1016/s0306-4522(00)00583-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The neuropeptide neurotensin and two classes of its receptors, the neurotensin receptor-1 and 2, are present in the suprachiasmatic nucleus of the mammalian hypothalamus. The suprachiasmatic nucleus houses the mammalian central circadian pacemaker, but the effects of neurotensin on cellular activity in this circadian pacemaker are unknown. In this study, we examined the effects of neurotensin on the spontaneous discharge rate of rat SCN cells in an in vitro slice preparation. Neurotensin (1-10 microM) increased cell firing rate in approximately 50% of cells tested, while approximately 10% of suprachiasmatic cells tested showed a decrease in firing rate in response to neurotensin. These effects of neurotensin were not altered by the GABA receptor antagonist bicuculline (20 microM) or the glutamate receptor antagonists, D-aminophosphopentanoic acid (50 microM) and 6-cyano-7-nitroquinoxaline-2,3-dione (20 microM). The neurotensin receptor selective antagonists SR48692 and SR142948a (10 microM) failed to antagonise neurotensin responses in the majority of cells examined. Compounds that function as agonists selective for the neurotensin-receptor subtypes 1 and 2, JMV-510 and JMV-431 respectively, elicited neurotensin-like responses in approximately 90% of cells tested. Six out of seven cells tested responded to both JMV-510 and JMV-431. Neuropeptide Y (100nM) treatment of suprachiasmatic nucleus slices was found to elicit profound suppression of neuronal firing rate. Co-application of neurotensin with neuropeptide Y significantly (P<0.05) reduced the duration of the response, as compared to that elicited with neuropeptide Y alone. Together, these results demonstrate for the first time the actions of neurotensin in the suprachiasmatic nucleus and raise the possibility that this neuropeptide may play a role in modulating circadian pacemaker function.
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Affiliation(s)
- A N Coogan
- School of Biological Sciences, University of Manchester, Manchester, M13 9PT, UK
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28
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Corticotropin-releasing factor increases in vitro firing rates of serotonergic neurons in the rat dorsal raphe nucleus: evidence for activation of a topographically organized mesolimbocortical serotonergic system. J Neurosci 2001. [PMID: 11027235 DOI: 10.1523/jneurosci.20-20-07728.2000] [Citation(s) in RCA: 167] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
In vivo studies suggest that the stress-related neuropeptide corticotropin-releasing factor (CRF) modulates serotonergic neurotransmission. To investigate the underlying mechanisms for this interaction, the present study examined the effects of CRF in vitro on dorsal raphe neurons that displayed electrophysiological and pharmacological properties consistent with a serotonergic phenotype. In the presence of either 1 or 2 mm Ca(2+), perfusion of ovine CRF or rat/human CRF rapidly and reversibly increased firing rates of a subpopulation (19 of 70, 27%) of serotonergic neurons predominantly located in the ventral portion of the dorsal raphe nucleus. For a given responsive neuron, the excitatory effects of CRF were reproducible, and there was no tachyphylaxis. Excitatory effects were dose-dependent (over the range of 0.1-1.6 micrometer) and were completely absent after exposure to the competitive CRF receptor antagonists alpha-helical CRF(9-41) or rat/human [d-Phe(12), Nle(21, 38), alpha-Me-Leu(37)]-CRF(12-41). Both the proportion of responsive neurons and the magnitude of excitatory responses to CRF in the ventral portion of the caudal dorsal raphe nucleus were markedly potentiated in slices prepared from animals previously exposed to isolation and daily restraint stress for 5 d. Immunohistochemical staining of the recorded slices revealed close associations between CRF-immunoreactive varicose axons and tryptophan hydroxylase-immunoreactive neurons in the area of the recordings, providing anatomical evidence for potential direct actions of CRF on serotonergic neurons. The electrophysiological properties and the distribution of responsive neurons within the dorsal raphe nucleus are consistent with the hypothesis that endogenous CRF activates a topographically organized mesolimbocortical serotonergic system.
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29
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Kwon YB, Kang MS, Son SS, Kim JT, Lee YH, Han HJ, Lee JH. Different frequencies of electroacupuncture modified the cellular activity of serotonergic neurons in brainstem. THE AMERICAN JOURNAL OF CHINESE MEDICINE 2001; 28:435-41. [PMID: 11154058 DOI: 10.1142/s0192415x00000519] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In this study, we evaluated whether different frequencies of electroacupuncture (EA) modified the activities of serotonergic neurons in the dorsal raphe (DR) and raphe magnus (RMg) using double labeling immunohistochemistry for Fos and serotonin. The results demonstrated that both high and low frequency EA increased the colocalization between Fos and serotonin in the DR, not in RMg as compared with anesthesia control. In addition, high frequency EA more potently increased the serotonergic activity in the DR rather than low frequency EA, suggesting that serotonergic pathway from the DR plays an important role in the high frequency EA analgesia.
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Affiliation(s)
- Y B Kwon
- Department of Veterinary Physiology, College of Veterinary Medicine, Seoul National University, Suwon, Korea
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30
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Enhanced neurotensin neurotransmission is involved in the clinically relevant behavioral effects of antipsychotic drugs: evidence from animal models of sensorimotor gating. J Neurosci 2001. [PMID: 11160439 DOI: 10.1523/jneurosci.21-02-00601.2001] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
To date, none of the available antipsychotic drugs are curative, all have significant side-effect potential, and a receptor-binding profile predictive of superior therapeutic ability has not been determined. It has become increasingly clear that schizophrenia does not result from the dysfunction of a single neurotransmitter system, but rather from an imbalance between several interacting systems. Targeting neuropeptide neuromodulator systems that concertedly regulate all affected neurotransmitter systems could be a promising novel therapeutic approach for schizophrenia. A considerable database is concordant with the hypothesis that antipsychotic drugs act, at least in part, by increasing the synthesis and release of the neuropeptide neurotensin (NT). In this report, we demonstrate that NT neurotransmission is critically involved in the behavioral effects of antipsychotic drugs in two models of antipsychotic drug activity: disrupted prepulse inhibition of the acoustic startle response (PPI) and the latent inhibition (LI) paradigm. Blockade of NT neurotransmission using the NT receptor antagonist 2-[[5-(2,6-dimethoxyphenyl)-1-(4-(N-(3-dimethylaminopropyl)-N-methylcarbamoyl)-2-isopropylphenyl)-1H- pyrazole-3-carbonyl]-amino]-adamantane-2-carboxylic acid, hydrochloride (SR 142948A) prevented the normal acquisition of LI and haloperidol-induced enhancement of LI. In addition, SR 142948A blocked the PPI-restoring effects of haloperidol and the atypical antipsychotic drug quetiapine in isolation-reared animals deficient in PPI. We also provide evidence of deficient NT neurotransmission as well as a left-shifted antipsychotic drug dose-response curve in isolation-reared rats. These novel findings, together with previous observations, suggest that neurotensin receptor agonists may represent a novel class of antipsychotic drugs.
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Li YQ, Kaneko T, Mizuno N. Collateral projections of nucleus raphe dorsalis neurones to the caudate-putamen and region around the nucleus raphe magnus and nucleus reticularis gigantocellularis pars alpha in the rat. Neurosci Lett 2001; 299:33-6. [PMID: 11166931 DOI: 10.1016/s0304-3940(00)01771-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
It was examined whether or not the nucleus raphe dorsalis (RD) neurons projecting to the caudate-putamen (CPu) might also project to the motor-controlling region around the nucleus raphe magnus (NRM) and nucleus reticularis gigantocellularis pars alpha (Gia) in the rat. Single RD neurons projecting to the CPu and NRM/Gia by way of axon collaterals were identified by the retrograde double-labeling method with fluorescent dyes, Fast Blue and Diamidino Yellow, which were injected respectively into the CPu and NRM/Gia. Then, serotonin (5-HT)-like immunoreactivity of the double-labeled RD neurons was examined immunohistochemically; approximately 60% of the double-labeled RD neurons showed 5-HT-like immunoreactivity. The results indicated that some of serotonergic and non-serotonergic RD neurons might control motor functions simultaneously at the levels of the CPu and NRM/Gia by way of axon collaterals.
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Affiliation(s)
- Y Q Li
- Department of Anatomy and K.K. Leung Brain Research Centre, The Fourth Military Medical University, Xi'an 710032, People's Republic of China
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Tamaki M, Han G, Hruby VJ. Practical and efficient synthesis of orthogonally protected constrained 4-guanidinoprolines. J Org Chem 2001; 66:1038-42. [PMID: 11430070 DOI: 10.1021/jo005626m] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- M Tamaki
- Department of Chemistry, University of Arizona, Tucson, Arizona 85721, USA
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Abstract
The possibility that the neuropeptide neurotensin (NT) may function as an endogenous antipsychotic compound was first hypothesized almost two decades ago. Since that time, considerable effort has been directed towards determining whether NT neurons mediate the effects of antipsychotic drugs (APDs). The anatomic, biochemical, behavioral, and clinical relevance of this hypothesis is reviewed. Although the majority of the available evidence is indirect, the availability of several NT receptor (NTR) antagonists have now made possible the direct examination of the involvement of the NT system in the mechanism of action of APDs. Preliminary studies in our laboratory demonstrate the ability of a selective NTR antagonist to block the effects of APDs in two models of sensory motor gating deficits characteristic of schizophrenia. These data, taken together with a compelling series of studies demonstrating that increases of NT/neuromedin N mRNA expression and NT content in the nucleus accumbens and striatum after chronic administration of APDs are predictive of clinical efficacy and extrapyramidal side effects, respectively, provide direct preclinical evidence for a role of the NT system in the clinical efficacy of APDs. Although effects of selective NTR antagonists in normal volunteers or schizophrenic patients have not been studied, and nonpeptidergic NTR agonists have not yet been identified, these cumulative results provide the groundwork for the use of NT-ergic compounds in the treatment of schizophrenia.
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Affiliation(s)
- B Kinkead
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, GA 30322, USA
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Abstract
The information presented in this article provides a basis for individual variability in the sensation of pain and the behavioral correlates associated with pain. The knowledge of pain-inhibitory and pain-facilitating pathways linked to cognitive, emotional, and stress-response systems leads to a greater understanding of the complexities of the experience of pain. Appreciation of the influence of these higher centers should lead to improvements in the clinical management of pain.
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Affiliation(s)
- L J Crofford
- Department of Internal Medicine, University of Michigan, Ann Arbor, USA
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Héaulme M, Leyris R, Soubrié P, Le Fur G. Stimulation by neurotensin of (3H)5-hydroxytryptamine (5HT) release from rat frontal cortex slices. Neuropeptides 1998; 32:465-71. [PMID: 9845009 DOI: 10.1016/s0143-4179(98)90073-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The effect of neurotensin (NT) on the K+-evoked (3H)5HT release from brain frontal cortex slices was studied in rats. NT(1-13) and NT(8-13) increased (3H)5HT release with EC50 values in the nanomolar range and Emax values in the range of 100% of control, whereas D-tyr11-NT was inactive. Concerning NT receptor antagonists, SR 48692 and SR 142948A antagonized with IC50 values of 4.8+/-1.8 nM and 4.5+/-1.8 nM respectively, the NT stimulated K+-evoked (3H)5HT release. SR 48527 also antagonized NT induced (3H)5HT release with an IC50 value of 0.95+/-0.06 nM whereas the inactive R(-) enantiomer SR 49711 only inhibited this effect with IC50 value close to 10(-6)M. The 5HT-releasing effect of NT was completely inhibited by tetrodotoxin suggesting that NT receptors involved in the control of 5-HT release are not located on 5-HT terminals. After a first NT (10(-7)M) application, the NT (10(-7)M, 10(-6)M) effect under K+ depolarization was drastically decreased, indicating that the NT receptor could be desensitized. No potentiating effect of NT on K+-evoked (3H)5HT release was observed in striatal and hippocampal slices. These results suggest that, in the rat frontal cortex, NT regulates 5HT release through a high affinity NT receptor not associated with 5HT terminals.
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Affiliation(s)
- M Héaulme
- Sanofi Recherche, Neuropsychiatry Department, Montpellier, France
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