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Przegalinski E, Chojnacka-Wojcik E, Filip M. Stimulation of postsynaptic 5-HT1A receptors is responsible for the anticonflict effect of ipsapirone in rats. J Pharm Pharmacol 2011; 44:780-2. [PMID: 1360535 DOI: 10.1111/j.2042-7158.1992.tb05521.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Abstract
Ipsapirone (1·25–10 mg kg−1), a non-benzodiazepine anxiolytic drug with high affinity for 5-hydroxytryptamine1A (5-HT1A) receptors, increased dose-dependently the number of punished licks in the drinking conflict test (Vogel test) in rats. The anticonflict effect of the drug administered at a dose of 5 mg kg−1 was not modified in animals with lesions of 5-HT neurones, produced by p-chloroamphetamine (PCA, 2× 10 mg kg−1). The anticonflict effect of ipsapirone in PCA-pretreated rats was antagonized by the 5-HT1A receptor and α1-adrenoceptor antagonist NAN-190 (1-(2-methoxyphenyl)-4-[4-(2-phthalimmido)]butylpiperazine hydrobromide; 0·5–1 mg kg−1), but not by the selective α1-adrenoceptor blocker prazosin (0·5 mg kg−1). Neither NAN-190 nor prazosin affected the punished response in PCA-pretreated rats. The present results indicate that the anticonflict effect of ipsapirone depends on stimulation of postsynaptic 5-HT1A receptors.
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Affiliation(s)
- E Przegalinski
- Institute of Pharmacology, Polish Academy of Sciences, Kraków
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2
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Iskra-Jopa J, Gołembiowska K, Dziubina A, Cybulski M, Duszyńska B, Chilmonczyk Z. In-vivo effects of the 1,2,4-piperazine derivatives MM5 and MC1, putative 5-HT agonists, on dopamine and serotonin release in rat prefrontal cortex. J Pharm Pharmacol 2010; 57:205-11. [PMID: 15720784 DOI: 10.1211/0022357055425] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Abstract
Two 1,2,4-substituted derivatives of piperazine were tested for their effect on dopamine and serotonin (5-HT) release in rat prefrontal cortex. Both compounds, 1-[4-(4-chinolin-2-yl-piperazin-1-yl)-butyl]piperidin-2-on (MM5) and 1-[4-(2-methyl-4-chinolin-2-yl-piperazin-1-yl)-butyl]-8-azaspiro [4.5]decano-7,9-dion (MC1), produced hypothermia in mice and showed affinity for 5-HT1A receptors in-vitro. Like the selective 5-HT1A agonist 8-OH-DPAT (0.1 mg kg−1), MM5 given peripherally (30 mg kg−1) decreased the extracellular 5-HT level in rat prefrontal cortex, while MC1 suppressed 5-HT release at a higher dose (40 mg kg−1), but not at a lower one (30 mg kg−1). The effect of both compounds on 5-HT release was abolished by WAY 100635 (0.3 mg kg−1). MC1 (30 and 40 mg kg−1), but not MM5, raised cortical dopamine, 3,4-dihydroxyphenylacetic acid (DOPAC) and extracellular homovanillic acid (HVA) levels. The effect of MC1 on dopamine release was reversed by neither WAY 100635 nor the non-selective 5-HT2 antagonist ritanserin (2 mg kg−1). However, ritanserin prevented the effect of the higher dose of MC1 on 5-HT release. The results of this study suggest that MM5 exhibits the profile of a 5-HT1A agonist devoid of dopaminergic activity. MC1 seems to possess moderate agonist activity at 5-HT1A and 5-HT2A receptors, while acting on 5-HT release in the rat prefrontal cortex. However, the facilitation of dopamine release by this compound does not seem to be related to its affinity for 5-HT1A and 5-HT2A receptors.
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MESH Headings
- 3,4-Dihydroxyphenylacetic Acid/chemistry
- 3,4-Dihydroxyphenylacetic Acid/metabolism
- 8-Hydroxy-2-(di-n-propylamino)tetralin/pharmacology
- Animals
- Dopamine/chemistry
- Dopamine/physiology
- Extracellular Fluid/chemistry
- Extracellular Fluid/drug effects
- Extracellular Fluid/metabolism
- Homovanillic Acid/chemistry
- Homovanillic Acid/metabolism
- Male
- Microdialysis/methods
- Piperazines/antagonists & inhibitors
- Piperazines/chemistry
- Piperazines/metabolism
- Piperazines/pharmacology
- Piperidones/metabolism
- Piperidones/pharmacology
- Poland
- Prefrontal Cortex/chemistry
- Prefrontal Cortex/drug effects
- Prefrontal Cortex/physiology
- Pyridines/pharmacology
- Radioligand Assay/methods
- Rats
- Rats, Wistar
- Receptor, Serotonin, 5-HT1A/drug effects
- Receptor, Serotonin, 5-HT1A/physiology
- Receptor, Serotonin, 5-HT2A/drug effects
- Receptor, Serotonin, 5-HT2A/physiology
- Ritanserin/pharmacology
- Serotonin/chemistry
- Serotonin/physiology
- Serotonin 5-HT1 Receptor Agonists
- Serotonin 5-HT2 Receptor Agonists
- Spiro Compounds/metabolism
- Spiro Compounds/pharmacology
- Structure-Activity Relationship
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Affiliation(s)
- Joanna Iskra-Jopa
- Pharmaceutical Research Institute, Rydygiera 8, PL-01-793 Warszawa, Poland
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3
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Müller CP, Carey RJ, Huston JP, De Souza Silva MA. Serotonin and psychostimulant addiction: Focus on 5-HT1A-receptors. Prog Neurobiol 2007; 81:133-78. [PMID: 17316955 DOI: 10.1016/j.pneurobio.2007.01.001] [Citation(s) in RCA: 232] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2006] [Revised: 12/04/2006] [Accepted: 01/03/2007] [Indexed: 01/03/2023]
Abstract
Serotonin(1A)-receptors (5-HT(1A)-Rs) are important components of the 5-HT system in the brain. As somatodendritic autoreceptors they control the activity of 5-HT neurons, and, as postsynaptic receptors, the activity in terminal areas. Cocaine (COC), amphetamine (AMPH), methamphetamine (METH) and 3,4-methylenedioxymethamphetamine ("Ecstasy", MDMA) are psychostimulant drugs that can lead to addiction-related behavior in humans and in animals. At the neurochemical level, these psychostimulant drugs interact with monoamine transporters and increase extracellular 5-HT, dopamine and noradrenalin activity in the brain. The increase in 5-HT, which, in addition to dopamine, is a core mechanism of action for drug addiction, hyperactivates 5-HT(1A)-Rs. Here, we first review the role of the various 5-HT(1A)-R populations in spontaneous behavior to provide a background to elucidate the contribution of the 5-HT(1A)-Rs to the organization of psychostimulant-induced addiction behavior. The progress achieved in this field shows the fundamental contribution of brain 5-HT(1A)-Rs to virtually all behaviors associated with psychostimulant addiction. Importantly, the contribution of pre- and postsynaptic 5-HT(1A)-Rs can be dissociated and frequently act in opposite directions. We conclude that 5-HT(1A)-autoreceptors mainly facilitate psychostimulant addiction-related behaviors by a limitation of the 5-HT response in terminal areas. Postsynaptic 5-HT(1A)-Rs, in contrast, predominantly inhibit the expression of various addiction-related behaviors directly. In addition, they may also influence the local 5-HT response by feedback mechanisms. The reviewed findings do not only show a crucial role of 5-HT(1A)-Rs in the control of brain 5-HT activity and spontaneous behavior, but also their complex role in the regulation of the psychostimulant-induced 5-HT response and subsequent addiction-related behaviors.
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Affiliation(s)
- Christian P Müller
- Institute of Physiological Psychology I, University of Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany.
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4
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Stachowicz K, Chojnacka-Wójcik E, Kłak K, Pilc A. Anxiolytic-like effect of group III mGlu receptor antagonist is serotonin-dependent. Neuropharmacology 2006; 52:306-12. [PMID: 17020774 DOI: 10.1016/j.neuropharm.2006.08.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2006] [Revised: 07/31/2006] [Accepted: 08/08/2006] [Indexed: 12/31/2022]
Abstract
Literature data have provided evidence that antagonists of group I metabotropic glutamate receptors (mGluRs) and agonists of group II/III mGluRs show anxiolytic-like properties in preclinical studies. However data reporting anxiolytic-like action of group III mGlu receptor antagonists were also published. In the present paper we investigated the anxiolytic-like activity of the group III mGlu receptor antagonist (RS)-alpha-cyclopropyl-4-phosphonophenylglycine (CPPG). To examine its anxiolytic-like effects, the basolateral amygdala was chosen as an injection site, as this brain region is involved in the regulation of anxiety-related behavior. To detect anxiolytic-like activity, the Vogel conflict-drinking test in rats was used. Intra-amygdalar injections of CPPG exhibited dose-dependent, potent anxiolytic-like action at a dose of 75 nmol, which was blocked by a concomitant administration of the group III mGlu receptor agonist CI (S,3R,4S)-1-aminocyclo-pentane-1,3,4-tricarboxylic acid (ACPT-I) at a dose of 7.5 nmol. The benzodiazepine receptor antagonist flumazenil (given intraperitoneally, 10 mg/kg) did not change the anxiolytic-like effect of CPPG, but that effect was abolished by the non-selective antagonist of 5-HT receptors metergoline and the antagonist of 5-HT2A/C receptors ritanserin (both given intraperitoneally at doses of 2 and 0.5 mg/kg, respectively). These findings suggest that the blockade of group III mGlu receptors in the amygdala is responsible for anxiolysis and that serotonergic, but not the benzodiazepine recognition site of the GABA-ergic system are involved in the anxiolytic-like response induced by group III mGlu antagonist.
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Affiliation(s)
- K Stachowicz
- Institute of Pharmacology, Polish Academy of Sciences, Smetna 12, 31-343 Krakow, Poland
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5
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Wesołowska A, Paluchowska M, Chojnacka-Wójcik E. Involvement of presynaptic 5-HT(1A) and benzodiazepine receptors in the anticonflict activity of 5-HT(1A) receptor antagonists. Eur J Pharmacol 2003; 471:27-34. [PMID: 12809949 DOI: 10.1016/s0014-2999(03)01814-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
In the present paper, we examined the effect of lesions of 5-hydroxytryptamine (5-HT) neurons, produced by p-chloroamphetamine (p-CA; 2 x 10 mg/kg), and the influence of flumazenil (Ro 15-1788, 10 mg/kg), a benzodiazepine receptor antagonist, on the anticonflict activity of N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-N-(2-pyridinyl)cyclohexanecarboxamide (WAY 100635) and trans-1-(2-methoxy-phenyl)-4-[4-succinimidocyclohexyl]piperazine (MP 349), pre- and postsynaptic 5-HT(1A) receptor antagonists, and 1-(2-methoxyphenyl)-4-(4-succinimidobutyl)piperazine (MM 77), a postsynaptic 5-HT(1A) receptor antagonist, in the Vogel conflict drinking test in rats. Diazepam was used as a reference compound. WAY 100635 (0.5-1 mg/kg), MP 349 (0.25-0.5 mg/kg), MM 77 (0.03-0.25 mg/kg) and diazepam (2.5-5 mg/kg) significantly increased the number of shocks accepted during experimental sessions in the conflict drinking test. In p-chloroamphetamine-pretreated rats, neither WAY 100635 (1 mg/kg) nor MP 349 (0.25 mg/kg) induced an anticonflict effect, whereas MM 77 (0.06 mg/kg) did produce it. Flumazenil fully blocked the anticonflict effects of WAY 100635 (1 mg/kg) and diazepam (5 mg/kg), and it partly but significantly reduced the anticonflict effects of MP 349 (0.25 mg/kg) and MM 77 (0.06 mg/kg). p-Chloroamphetamine and flumazenil alone were inactive in the conflict drinking test. The present results suggest that, first, the anticonflict effect of the 5-HT(1A) receptor antagonists, WAY 100635 and MP 349, but not MM 77, is linked to the presynaptically located 5-HT(1A) receptors, and second, benzodiazepine receptors are indirectly involved in such effects of WAY 100635, MP 349 and MM 77, due maybe to a possible interaction between the 5-HT and the gamma-aminobutyric acid (GABA)/benzodiazepine systems.
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Affiliation(s)
- Anna Wesołowska
- Institute of Pharmacology, Polish Academy of Sciences, 31-343 Cracow, Poland
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6
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Abstract
Fear is an adaptive component of the acute "stress" response to potentially-dangerous (external and internal) stimuli which threaten to perturb homeostasis. However, when disproportional in intensity, chronic and/or irreversible, or not associated with any genuine risk, it may be symptomatic of a debilitating anxious state: for example, social phobia, panic attacks or generalized anxiety disorder. In view of the importance of guaranteeing an appropriate emotional response to aversive events, it is not surprising that a diversity of mechanisms are involved in the induction and inhibition of anxious states. Apart from conventional neurotransmitters, such as monoamines, gamma-amino-butyric acid (GABA) and glutamate, many other modulators have been implicated, including: adenosine, cannabinoids, numerous neuropeptides, hormones, neurotrophins, cytokines and several cellular mediators. Accordingly, though benzodiazepines (which reinforce transmission at GABA(A) receptors), serotonin (5-HT)(1A) receptor agonists and 5-HT reuptake inhibitors are currently the principle drugs employed in the management of anxiety disorders, there is considerable scope for the development of alternative therapies. In addition to cellular, anatomical and neurochemical strategies, behavioral models are indispensable for the characterization of anxious states and their modulation. Amongst diverse paradigms, conflict procedures--in which subjects experience opposing impulses of desire and fear--are of especial conceptual and therapeutic pertinence. For example, in the Vogel Conflict Test (VCT), the ability of drugs to release punishment-suppressed drinking behavior is evaluated. In reviewing the neurobiology of anxious states, the present article focuses in particular upon: the multifarious and complex roles of individual modulators, often as a function of the specific receptor type and neuronal substrate involved in their actions; novel targets for the management of anxiety disorders; the influence of neurotransmitters and other agents upon performance in the VCT; data acquired from complementary pharmacological and genetic strategies and, finally, several open questions likely to orientate future experimental- and clinical-research. In view of the recent proliferation of mechanisms implicated in the pathogenesis, modulation and, potentially, treatment of anxiety disorders, this is an opportune moment to survey their functional and pathophysiological significance, and to assess their influence upon performance in the VCT and other models of potential anxiolytic properties.
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Affiliation(s)
- Mark J Millan
- Psychopharmacology Department, Centre de Rescherches de Croissy, Institut de Recherches (IDR) Servier, 125 Chemin de Ronde, 78290 Croissy-sur-Seine, Paris, France.
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7
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Millan MJ, Brocco M. The Vogel conflict test: procedural aspects, gamma-aminobutyric acid, glutamate and monoamines. Eur J Pharmacol 2003; 463:67-96. [PMID: 12600703 DOI: 10.1016/s0014-2999(03)01275-5] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A multitude of mechanisms are involved in the control of emotion and in the response to stress. These incorporate mediators/targets as diverse as gamma-aminobutyric acid (GABA), excitatory amino acids, monoamines, hormones, neurotrophins and various neuropeptides. Behavioural models are indispensable for characterization of the neuronal substrates underlying their implication in the etiology of anxiety, and of their potential therapeutic pertinence to its management. Of considerable significance in this regard are conflict paradigms in which the influence of drugs upon conditioned (trained) behaviours is examined. For example, the Vogel conflict test, which was introduced some 30 years ago, measures the ability of drugs to release the drinking behaviour of water-deprived rats exposed to a mild aversive stimulus ("punishment"). This model, of which numerous procedural variants are discussed herein, has been widely used in the evaluation of potential anxiolytic agents. In particular, it has been exploited in the characterization of drugs interacting with GABAergic, glutamatergic and monoaminergic networks, the actions of which in the Vogel conflict test are summarized in this article. More recently, the effects of drugs acting at neuropeptide receptors have been examined with this model. It is concluded that the Vogel conflict test is of considerable utility for rapid exploration of the actions of anxiolytic (and anxiogenic) drugs. Indeed, in view of its clinical relevance, broader exploitation of the Vogel conflict test in the identification of novel classes of anxiolytic agents, and in the determination of their mechanisms of action, would prove instructive.
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Affiliation(s)
- Mark J Millan
- Psychopharmacology Department, Institut de Recherches Servier, Centre de Recherches de Croissy, 125 Chemin de Ronde, 78290 Croissy/Seine, Paris, France.
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8
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Flügge G, Kramer M, Rensing S, Fuchs E. 5HT1A-receptors and behaviour under chronic stress: selective counteraction by testosterone. Eur J Neurosci 2003. [DOI: 10.1046/j.1460-9568.1998.00280.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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9
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Miao FJ, Benowitz NL, Heller PH, Levine JD. Contribution of adrenal hormones to nicotine-induced inhibition of synovial plasma extravasation in the rat. Br J Pharmacol 1997; 120:298-304. [PMID: 9117123 PMCID: PMC1564364 DOI: 10.1038/sj.bjp.0700884] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
1. In this study, we examined the mechanism(s) by which s.c. nicotine inhibits synovial plasma extravasation. We found that nicotine dose-dependently inhibited bradykinin (BK)- and platelet activating factor (PAF)-induced plasma extravasation. 2. The effect of nicotine on both BK- and PAF-induced plasma extravasation was attenuated by adrenal medullectomy. ICI-118,551 (a selective beta 2-adrenoceptor blocker) (30 micrograms ml-1, intra-articularly) significantly attenuated the inhibitory action of high-dose (1 mg kg-1) nicotine on BK-induced plasma extravasation without affecting the inhibition by low- (0.01 microgram kg-1) dose nicotine or that on PAF-induced plasma extravasation by nicotine at any dose. This suggested that beta 2-adrenoceptors mediate the inhibitory actions of high-dose, but not low-dose, nicotine. We also found that systemic naloxone (an opioid receptor antagonist) (two hourly injections of 1 mg kg-1, i.p.) attenuated the inhibitory action produced by all doses of nicotine on BK- or PAF-induced plasma extravasation, suggesting the contribution of endogenous opioids. 3. RU-38,486 (a glucocorticoid receptor antagonist) (30 mg kg-1, s.c.), and metyrapone (a glucocorticoid synthesis inhibitor) (two hourly injections of 100 mg kg-1, i.p.) both attenuated the action of high-dose nicotine without affecting that of low-dose nicotine. 4. Spinal mecamylamine (a nicotinic receptor antagonist) (0.025 mg kg-1, intrathecally, i.t.) attenuated the action of high-dose, but not low-dose, nicotine, suggesting that part of the action of high-dose nicotine is mediated by spinal nicotinic receptors. 5. Combined treatment with ICI-118,551, naloxone and RU-38,486 attenuated the action of low-dose nicotine by an amount similar to that produced by naloxone alone but produced significantly greater attenuation of the effect of high-dose nicotine when compared to the action of any of the three antagonists alone.
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Affiliation(s)
- F J Miao
- Department of Medicine, University of California, San Francisco School of Medicine 94143-0452, USA
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10
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Inoue T, Hashimoto S, Tsuchiya K, Izumi T, Ohmori T, Koyama T. Effect of citalopram, a selective serotonin reuptake inhibitor, on the acquisition of conditioned freezing. Eur J Pharmacol 1996; 311:1-6. [PMID: 8884229 DOI: 10.1016/0014-2999(96)00391-3] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The present study examined the effects of the selective serotonin (5-hydroxytryptamine, 5-HT) reuptake inhibitor citalopram on the acquisition of conditioned freezing, an index of anxiety. Acute treatment with citalopram (1-10 mg/kg) dose dependently prevented the acquisition of conditioned freezing, while acute treatment with noradrenaline or dopamine reuptake inhibitors failed. The acute effect of citalopram was not antagonized by the 5-HT1A receptor antagonist NAN190, 1-(2-methoxyphenyl)-4-[4-(2-phthalimmido)butyl]piperazine or the 5-HT2A/2C receptor antagonist ICI169,369, 2-(2-dimethylaminoethylthio)-3-phenylquinoline hydrochloride. These results indicate that selective 5-HT reuptake inhibitors reduce not only the expression of conditioned freezing as reported previously, but also the acquisition of conditioned freezing. Both these effects of selective 5-HT reuptake inhibitors may be related to their clinical efficacy in the treatment of anxiety disorders.
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Affiliation(s)
- T Inoue
- Department of Psychiatry, Hokkaido University School of Medicine, Sapporo, Japan
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11
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Wedzony K, Maćkowiak M, Fijał K, Gołembiowska K. Ipsapirone enhances the dopamine outflow via 5-HT1A receptors in the rat prefrontal cortex. Eur J Pharmacol 1996; 305:73-8. [PMID: 8813534 DOI: 10.1016/0014-2999(96)00150-1] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
In the present study, we investigated both the effect of ipsapirone on the dopamine outflow and its selectivity towards 5-HT1A receptors in the rat prefrontal cortex. Using a brain microdialysis method in freely moving animals, it was found that ipsapirone, 5 and 10 mg/kg dose-dependently enhanced the outflow of dopamine, while 2.5 mg/kg was ineffective. The above effects of ipsapirone were mimicked by buspirone (2.5 and 5 mg/kg), another 5-HT1A receptor agonist, but not 1-PP (1-pyrimidinylpiperazine, 5 mg/kg)-a centrally active metabolite of ipsapirone. The effect of ipsapirone (10 mg/kg) on the dopamine outflow in the rat prefrontal cortex was antagonized by 1-(2-methoxyphenyl)-4-[4-(2-phthalimido)butyl]piperazine (NAN-190, 1 mg/kg) and (N-tert-butyl-3-(4-(2-methoxyphenylpiperazin-1-yl)-2- phenylpropionamide (WAY 100135, 10 mg/k.g.), i.e. substances with agonistic/antagonistic and antagonistic properties in relation to 5-HT1A receptors, respectively. NAN-190 (1 mg/kg) enhanced the outflow of dopamine, while WAY 100135 (10 mg/kg) failed to alter it. It is concluded that 5-HT1A receptor agonists may be involved in the regulation of dopaminergic neurotransmission in the rat prefrontal cortex and may have therapeutic potential in the treatment of disorders associated with dysfunction of the mesocortical dopaminergic system.
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Affiliation(s)
- K Wedzony
- Institute of Pharmacology, Polish Academy of Sciences, Kraków, Poland.
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12
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Przegalinski E, Tatarczyńska E, Chojnacka-Wójcik E. The role of hippocampal 5-hydroxytryptamine 1A (5-HT1A) receptors in the anticonflict activity of beta-adrenoceptor antagonists. Neuropharmacology 1995; 34:1211-7. [PMID: 8532192 DOI: 10.1016/0028-3908(95)00087-m] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The nonselective beta-adrenoceptor antagonists pindolol and cyanopindolol, which bind to 5-HT1A and 5-HT1A receptors showed an anticonflict effect by increasing the number of punished licks in the Vogel conflict test in rats, when administered directly into the CA, region of the dorsal hippocampus (i.hp.). The maximum effect was observed after intrusion of 1 microgram of pindolol and 3 microgram of cyanopindolol. However, the selective beta 1-and beta2-adrenoceptor antagonists betaxolol and ICI 118,551, respectively, which have a negligible affinity for 5-HT receptors, did not affect the punished responding, when administered i.hp. in doses up to 10 micrograms. The anticonflict effect of pindolol (1 microgram) was significantly reduced by (S)-WAY 100135, a selective 5-HT1A-receptor antagonist, administered i.hp (0.1 microgram) or s.c. (10 mg/kg). Furthermore, (S)-WAY 100135 injected i.hp (0.3 micrograms) significantly antagonized the anticonflict effect of pindolol injected i.p. (8 mg/kg). (S)-WAY 100135 given alone i.hp. (0.03-3 micrograms) or s.c. (5-10 mg/kg) did not affect the punished responding in rats. These results indicate that the anticonflict effect of the beta-blockers which were tested, or at least pindolol, depends on their agonist action on postsynaptic 5-HT1A receptors located in the hippocampus.
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Affiliation(s)
- E Przegalinski
- Institute of Pharmacology, Polish Academy of Sciences, Kraków, Poland
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13
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Abstract
The effects of manipulating 5-hydroxytryptamine (5HT) neuronal function in humans and in animals are reviewed. 5HT pathways do not have a unitary function in modulating anxiety. It is proposed that, rather than acting as input or output channels for brain aversive systems, these pathways provide information concerning waking/motor status, which is crucial to the organisation of appropriate responses to threat. Each terminal region can make use of this information in different ways. Globally, the influence of 5HT neurones on higher centres appears predominantly to facilitate information processing relevant to threat, while their major influence on brainstem centres may be a restraining one.
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Affiliation(s)
- S L Handley
- Department of Pharmaceutical and Biological Sciences, Aston University, Birmingham, U.K
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14
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Griebel G. 5-Hydroxytryptamine-interacting drugs in animal models of anxiety disorders: more than 30 years of research. Pharmacol Ther 1995; 65:319-95. [PMID: 7644567 DOI: 10.1016/0163-7258(95)98597-j] [Citation(s) in RCA: 344] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
An overview of the behavioral data arising from the vast literature concerning the involvement of 5-hydroxytryptamine (5-HT) neurotransmission in the regulation of anxiety is presented. More than 1300 experiments were carried out in this area and they provide evidence that: (1) results obtained in ethologically based animal models of anxiety with drugs stimulating 5-HT transmission are most consistent with the classic 5-HT hypothesis of anxiety in that they show an increase in animals' emotional reactivity; (2) no category of anti-anxiety models are selectively sensitive to the anxiolytic-like effects of drugs targetting 5-HT1A, 5-HT2A or 5-HT2C receptor subtypes; (3) anxiolytic-like effects of 5-HT3 receptor antagonists, in the great part, are revealed by models based on spontaneous behaviors. Taken together, these observations lead to the conclusion that different 5-HT mechanisms, mediated by different receptor subtypes, are involved in the genesis of anxiety.
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Affiliation(s)
- G Griebel
- Laboratoire de Psychophysiologie, Strasbourg, France
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15
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Pharmacological characterization of enantiomers of 8-thiomethyl-2-(di-n-propylamino)tetralin, potent and selective 5-HT1A receptor agonists. Drug Dev Res 1995. [DOI: 10.1002/ddr.430340110] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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16
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Abstract
The present study investigates the role of serotonergic systems in anabolic steroid-induced aggression. An animal model of aggressive dominance was used to assess the chronic effects of testosterone propionate. When rats that had become dominant following administration of testosterone propionate received serotonergic agonists with selectivity for the 5-HT1A receptor (8-OH-DPAT, buspirone, gepirone), the 5-H1B receptor (eltoprazine, TFMPP), or the 5-HT2A/2C receptor (DOM), a dose-dependent decrease in dominance was demonstrated. Pretreatment with three serotonergic antagonists (pizotyline, pirenpirone, and pindolol) blocked agonist-induced reductions in dominance in varying degrees. Nonserotonergic agonists with CNS depressant effects were also tested in dominant animals. The benzodiazepine, chlordiazepoxide, did not reduce dominance except at doses that interfered with motor behavior. The opioid agonist, morphine, dose dependently decreased dominance, but this effect was reversible with administration of the serotonergic antagonist, pirenpirone, suggesting the antidominant effect of morphine had a serotonergic component. Biochemical experiments demonstrated that following chronic testosterone propionate, there was a decrease in levels of 5-HT and 5-HIAA in the hippocampus but not in the striatum or the frontal cortex. Chronic testosterone propionate also caused an increase in the affinity of [3H]8-OH-DPAT for the 5-HT1A receptor but no corresponding change in the density of 5-HT1A binding sites in the hippocampus. There was also no change in the properties of the 5-HT2 receptor in the frontal cortex following chronic testosterone propionate. These data suggest that serotonergic systems may play an important role in the control of anabolic steroid-induced aggressive dominance.
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Affiliation(s)
- K R Bonson
- Department of Pharmacology and Therapeutics, School of Medicine and Biomedical Sciences, State University of New York at Buffalo 14214-3000
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17
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Przegaliński E, Tatarczyńska E, Kłodzińska A, Chojnacka-Wójcik E. The role of postsynaptic 5-HT1A receptors in the anticonflict effect of ipsapirone. Neuropharmacology 1994; 33:1109-15. [PMID: 7838324 DOI: 10.1016/0028-3908(94)90150-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
In the present paper we have studied the anticonflict effect (in the Vogel test) of ipsapirone, a partial agonist of 5-hydroxytryptamine1A (5-HT1A) receptors, administered to the hippocampus of rats. In addition, a comparison of the effect of ipsapirone with the effect of other 5-HT1A receptor ligands (busipone, gepirone and 8-OH-DPAT) has been carried out. Finally, the interaction between ipsapirone and NAN-190 (an antagonist of 5-HT1A receptors and alpha 1-adrenoceptors) has also been examined. It has been found that ipsapirone injected intrahippocampally (i.hp.) in doses of 0.3, 1 and 3 micrograms (bilaterally) shows an anticonflict effect by increasing the number of punished licks by about 36, 151 and 109%, respectively. A similar effect has also been found after i.hp. injections of buspirone (0.3-3 micrograms), gepirone (3-30 micrograms) and 8-OH-DPAT (0.3-3 micrograms). We have also demonstrated that the anticonflict effect of ipsapirone injected i.hp. is antagonized by NAN-190 administered i.hp. (0.3 or 1 microgram) or intraperitoneally (i.p., 1 mg/kg). Furthermore, NAN-190 injected i.hp. (0.3 microgram) antagonizes the anticonflict effect of ipsapirone administered i.p. (5 mg/kg). At the same time, the anticonflict effects of ipsapirone are not affected by prazosin (0.3-1 microgram i.hp. or 0.5-1 mg/kg i.p.), a selective antagonist of alpha 1-adrenoceptors. Our results seem to indicate that the anticonflict effect of ipsapirone stems from stimulation of postsynaptic 5-HT1A receptors in the hippocampus.
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Affiliation(s)
- E Przegaliński
- Institute of Pharmacology, Polish Academy of Sciences, Kraków
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18
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Przegaliński E, Filip M, Chojnacka-Wójcik E, Tatarczyńska E. The role of 5-hydroxytryptamine1A (5-HT1A) receptors in the anticonflict activity of beta-adrenoceptor antagonists. Pharmacol Biochem Behav 1994; 47:873-8. [PMID: 7913223 DOI: 10.1016/0091-3057(94)90290-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Using the conflict drinking test as a model, we studied in rats the effect of the nonselective beta-adrenoceptor blockers pindolol and cyanopindolol which bind to 5-HT1A and 5-HT1B receptors, and of the selective beta 1- and beta 2-adrenoceptor antagonists betaxolol and ICI 118,551, respectively, which have a negligible affinity for 5-HT receptors. Both pindolol (2.0-8.0 mg/kg) and cyanopindolol (0.5-2.0 mg/kg) showed an anticonflict effect, having dose dependently increased the number of punished licks. On the other hand, neither betaxolol nor ICI 118,551--administered separately or in combination--affected the punished responding. The anticonflict effects of pindolol and cyanopindolol were completely abolished by the 5-HT1A receptor and alpha 1-adrenoceptor antagonist 1-(2-methoxyphenyl)-4-[4-(2-phtalimmido)butyl]piperazine (NAN-190), but were not modified by the selective alpha 1(-)-adrenoceptor antagonist prazosin. The effects of pindolol and cyanopindolol were also not modified in animals with lesions of 5-HT neurons, produced by p-chloroamphetamine (PCA). Moreover, it was also found that the anticonflict effects of pindolol and cyanopindolol in PCA-pretreated rats were antagonized by NAN-190 but not prazosin. Our results indicate that the anticonflict effects of pindolol and cyanopindolol depend on their agonist action on postsynaptic 5-HT1A receptors.
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Affiliation(s)
- E Przegaliński
- Polish Academy of Sciences, Institute of Pharmacology, Kraków
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19
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Handley SL, McBlane JW, Critchley MA, Njung'e K. Multiple serotonin mechanisms in animal models of anxiety: environmental, emotional and cognitive factors. Behav Brain Res 1993; 58:203-10. [PMID: 8136047 DOI: 10.1016/0166-4328(93)90104-x] [Citation(s) in RCA: 102] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Responses to serotonergic drugs in animal models of 'anxiety' are reviewed with emphasis on the elevated X-maze. Evidence for the 'classic' hypothesis, that decreasing serotonergic function is anxiolytic and increasing it anxiogenic, is most consistent in models of behavioural inhibition where the stimulus inhibits an approach response (conflict models). However, paradoxical drug effects are also frequent, especially where the aversive stimulus evokes an active response. Both types of drug effect are equally frequent in the elevated X-maze. 'Anxiety' models may detect multiple sites and mechanisms of action of the same drug; this may indicate multiple anxiety-related neurological mechanisms in the brain. However, not all drug effects in 'anxiety' models are necessarily related to anxiety itself. It is possible that cognitive factors may affect stimulus evaluation, and response inhibition by an aversive stimulus may be a special case of a wider role for serotonin in behavioural control. Clinical implications of these observations are considered.
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Affiliation(s)
- S L Handley
- Pharmaceutical Sciences Institute, Aston University, Birmingham, UK
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20
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Abstract
Contradictory evidence exists concerning the anxiolytic effects of 5-HT1A agonists in the conflict test. In the present work, a modification of the Vogel conflict model was used to assess different doses of diazepam (0.1-5.6 mg/kg), ipsapirone (1.0-17.8 mg/kg), buspirone (1.7-17.8 mg/kg), and indorenate (0.56-17.8 mg/kg) in rats receiving two different electric shock intensities (0.16 and 0.32 mA). The results show that the three 5-HT1A agonists had a smaller anticonflict effect than diazepam. The anticonflict effect with each compound was of a greater magnitude at 0.16 mA intensity than at 0.32 mA. This study shows that, using different electric shock intensities, compounds produce a differential effect: the anticonflict effects were more pronounced with the lower electric shock intensity than with the higher intensity. The present results suggest that the use of different shock intensities can play distinct roles over the drug's effect in the conflict test.
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Affiliation(s)
- A Meneses
- Departamento de Farmacología y Toxicología, CINVESTAV-IPN, México, D.F., México
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21
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Cox RF, Meller E, Waszczak BL. Electrophysiological evidence for a large receptor reserve for inhibition of dorsal raphe neuronal firing by 5-HT1A agonists. Synapse 1993; 14:297-304. [PMID: 8248853 DOI: 10.1002/syn.890140407] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Previous studies [Meller et al. (1990) Mol. Pharmacol., 37:231-237] have shown that a large receptor reserve exists for the inhibition of serotonin synthesis in rat cortex and hippocampus by the 5-HT1A agonist 8-hydroxy-2(di-n-propylamino)tetralin (8-OH-DPAT), whereas little or no reserve exists for the lower efficacy agonists ipsapirone and BMY 7378. The current studies were undertaken to determine if the above drugs exhibit similar relative efficacies and receptor reserves in an electrophysiological model of 5-HT1A receptor activation, i.e., the inhibition of dorsal raphe cell firing. Intravenous dose-response curves were constructed in untreated control rats, or in rats which received an injection of the irreversible receptor inactivator N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ, 6 mg/kg, s.c.) 24 hours before recording. All three drugs fully inhibited dorsal raphe cell firing in control rats (ED50's: 1.5 micrograms/kg, 8-OH-DPAT; 30.0 micrograms/kg, ipsapirone; 17.5 micrograms/kg, BMY 7378). However, unlike effects on serotonin synthesis, EEDQ treatments caused no depression of the maximal inhibitory response for any of the agonists, although all dose-response curves were shifted to the right (ED50's: 10.1 micrograms/kg, 6.7-fold shift, 8-OH-DPAT; 139.9 micrograms/kg, 4.7-fold shift, ipsapirone; 53.8 micrograms/kg, 3.1-fold shift, BMY 7378). Although the order of agonist efficacies was similar for both inhibition of serotonin synthesis and dorsal raphe cell firing (8-OH-DPAT > ipsapirone > BMY 7378), a large (> 50%) receptor reserve was estimated for all three drugs in this electrophysiological system.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- R F Cox
- Pharmacology Section, Northeastern University, Boston, Massachusetts 02115
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22
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Treit D, Robinson A, Rotzinger S, Pesold C. Anxiolytic effects of serotonergic interventions in the shock-probe burying test and the elevated plus-maze test. Behav Brain Res 1993; 54:23-34. [PMID: 8504010 DOI: 10.1016/0166-4328(93)90045-r] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Although serotonergic neural systems have been implicated in the control of anxiety for a number of years, evidence in favour of this role is controversial. The present experiments were designed to further characterize the putative role of serotonin (5-HT) in anxiety, using two pharmacologically validated animal models: the elevated plus-maze and the shock-probe burying tests. If the integrity of 5-HT neural systems is necessary for the expression of 'anxious' behaviors, then disruption of 5-HT systems should produce effects in the plus-maze and shock-probe tests that are similar to those of anxiolytic drugs. In the present experiments, serotonergic function was disrupted in rats, either by chemical depletion using the synthesis inhibitor p-CPA, by inhibitory autoreceptor activation using the selective 5-HT1A receptor ligand 8-OH-DPAT, or by electrolytic lesions of the serotonin-containing, dorsal raphe nucleus. p-CPA and dorsal raphe lesions produced robust anxiolytic effects in the elevated plus-maze and the shock-probe burying tests, whereas 8-OH-DPAT produced anxiolytic effects only in the shock-probe burying test, and 'anxiogenic' effects in the elevated plus-maze test. Although these results generally support the view that serotonin plays a role in the expression of 'anxious' behavior, the opposite effects of 8-OH-DPAT in the two behavioral paradigms suggest that the 5-HT1A receptor subtype exerts differential control over different types of experimental anxiety.
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Affiliation(s)
- D Treit
- Department of Psychology, University of Alberta, Edmonton, Canada
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23
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Baudrie V, De Vry J, Broqua P, Schmidt B, Chaouloff F, Glaser T. Subchronic treatment with anxiolytic doses of the 5-HT1A receptor agonist ipsapirone does not affect 5-HT2 receptor sensitivity in the rat. Eur J Pharmacol 1993; 231:395-406. [PMID: 8095465 DOI: 10.1016/0014-2999(93)90116-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Acute stimulation of 5-HT1A receptors has been reported to diminish some 5-HT2 receptor-mediated responses in the rat, but there is controversy as to whether repeated stimulation of 5-HT1A receptors leads to identical changes. In this study, we tested the influence of repeated treatment with the 5-HT1A receptor agonist ipsapirone (0.5 g/l in drinking water for 21 days) on some 5-HT2 receptor-mediated responses elicited by the acute injection of the 5-HT1C/5-HT2 receptor agonist 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI). These responses included hyperglycemia, corticosterone release, and head shakes; cortical 5-HT2 receptor number and DOI-induced prolactin release (a 5-HT1C/5-HT2 receptor-mediated event) were also analyzed. In a first series of experiments, ipsapirone administration for 1, 8, 15, and 20 days reduced the duration fo shock-induced ultrasonic vocalization. Ipsapirone administration for 21 days reduced fluid intake and decreased body weight, but did not affect baseline plasma glucose, corticosterone, and prolactin levels or cortical 5-HT2 receptor number. The increases in plasma glucose levels elicited by acute injection of either DOI (0.1-1 mg/kg i.v.) or clonidine (an alpha 2-adrenoceptor agonist; 0.05 mg/kg i.v.) were reduced in ipsapirone-pretreated rats. The maximal effects of DOI and clonidine on plasma corticosterone or prolactin levels were not affected by ipsapirone pretreatment. Ipsapirone decreased the area under the corticosterone curve in both DOI- and clonidine-treated rats. Lastly, the head-shake response to DOI (0.5-2 mg/kg s.c.) was similar in vehicle- and ipsapirone-pretreated rats. These data indicate that a 3-week treatment with anxiolytic doses of the 5-HT1A receptor agonist ipsapirone does not desensitize 5-HT2 receptors.
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Affiliation(s)
- V Baudrie
- Laboratoire de Pharmacologie, CNRS, CHU Necker, Paris, France
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24
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Pollard GT, Nanry KP, Howard JL. Effects of tandospirone in three behavioral tests for anxiolytics. Eur J Pharmacol 1992; 221:297-305. [PMID: 1358655 DOI: 10.1016/0014-2999(92)90716-h] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The azapirone putative anxiolytic tandospirone was evaluated in two behavioral screening methods that identify known azapirone anxiolytics and one method that identifies only sedative-hypnotic anxiolytics. Tandospirone produced a large increase in punished key-pecking for food in pigeon and a large increase in cork gnawing in rat. It did not produce a large increase in punished lever-pressing for food in rat, a result that to some extent contradicts reports from other laboratories. It was equipotent with buspirone in pigeon, but in rat it was ten times less potent than buspirone in disrupting the lever-press response and increasing cork gnawing. The results indicate that tandospirone is qualitatively similar to the other azapirone anxiolytics buspirone, gepirone and ipsapirone and is different from sedative-hypnotic anxiolytics.
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Affiliation(s)
- G T Pollard
- Burroughs Wellcome Co., Research Triangle Park, NC 27709
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25
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Chojnacka-Wójcik E, Kłodzińska A. Involvement of 5-HT1B receptors in the anticonflict effect of m-CPP in rats. J Neural Transm (Vienna) 1992; 87:87-96. [PMID: 1348421 DOI: 10.1007/bf01245010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The anticonflict activity of m-CPP, a non-selective agonist of 5-HT receptors, was studied in the drinking conflict test in rats. m-CPP administered in doses of 0.125-0.5 mg/kg increased the number of punished licks, the maximum effect having been observed after a dose of 0.25 mg/kg. The anticonflict effect of m-CPP (0.25 mg/kg) was antagonized by the non-selective 5-HT antagonist metergoline (1-4 mg/kg) and by the beta-adrenoceptor blocker SDZ 21009 (2 and 4 mg/kg) with affinity for 5-HT1A and 5-HT1B receptors. On the other hand, the 5-HT1A receptor antagonist NAN-190 (0.5 and 1 mg/kg), the 5-HT2 receptor antagonist ritanserin (0.25 and 0.5 mg/kg), and the beta-blockers betaxolol (8 mg/kg) and ICI 118,551 (8 mg/kg) with no affinity for 5-HT receptors did not affect the effect of m-CPP. The effect of m-CPP was not modified, either, in animals with the 5-HT lesion produced by p-chloroamphetamine. These results suggest that the anticonflict effect of m-CPP described above results from stimulation of 5-HT1B receptors--most probably these which are located postsynaptically.
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26
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Shimizu H, Tatsuno T, Tanaka H, Hirose A, Araki Y, Nakamura M. Serotonergic Mechanisms in Anxiolytic Effect of Tandospirone in the Vogel Conflict Test. ACTA ACUST UNITED AC 1992; 59:105-12. [PMID: 1354771 DOI: 10.1254/jjp.59.105] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
To clarify which 5-HT1A receptors, autoreceptors located in the raphe nuclei or post-synaptic receptors in the forebrain areas receiving a 5-HT input, mediate the anticonflict action of tandospirone (a 5-HT1A receptor-related anxiolytics), the behavioral effects of tandospirone were studied in 5,7-dihydroxytryptamine (5,7-DHT) treated rats. By measuring both monoamines and their metabolite levels and densities of [3H]8-OH-DPAT binding in 5,7-DHT-treated rat brain, we confirmed that pretreatment with 5,7-DHT destroyed 5-HT neurons selectively without affecting postsynaptic 5-HT1A receptors located on the postsynaptic neurons. This selective destruction produced no significant changes in the drinking behavior of rats in either punished or unpunished sessions of the Vogel conflict test. Furthermore, this destruction altered neither the effect of tandospirone on punished responding in this procedure nor the potency of tandospirone to induce a flat body posture in rats, which is known as the "serotonin behavioral syndrome". These results suggested that the anticonflict action of tandospirone may be produced, at least in part, by binding to postsynaptic 5-HT1A receptors and activating them as agonists, and not to 5-HT1A autoreceptors located on the cell bodies of 5-HT neurons.
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Affiliation(s)
- H Shimizu
- Research Laboratories, Sumitomo Pharmaceuticals Co., Ltd., Osaka, Japan
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