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Vitrac C, Benoit-Marand M. Monoaminergic Modulation of Motor Cortex Function. Front Neural Circuits 2017; 11:72. [PMID: 29062274 PMCID: PMC5640772 DOI: 10.3389/fncir.2017.00072] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2017] [Accepted: 09/19/2017] [Indexed: 01/09/2023] Open
Abstract
Elaboration of appropriate responses to behavioral situations rests on the ability of selecting appropriate motor outcomes in accordance to specific environmental inputs. To this end, the primary motor cortex (M1) is a key structure for the control of voluntary movements and motor skills learning. Subcortical loops regulate the activity of the motor cortex and thus contribute to the selection of appropriate motor plans. Monoamines are key mediators of arousal, attention and motivation. Their firing pattern enables a direct encoding of different states thus promoting or repressing the selection of actions adapted to the behavioral context. Monoaminergic modulation of motor systems has been extensively studied in subcortical circuits. Despite evidence of converging projections of multiple neurotransmitters systems in the motor cortex pointing to a direct modulation of local circuits, their contribution to the execution and learning of motor skills is still poorly understood. Monoaminergic dysregulation leads to impaired plasticity and motor function in several neurological and psychiatric conditions, thus it is critical to better understand how monoamines modulate neural activity in the motor cortex. This review aims to provide an update of our current understanding on the monoaminergic modulation of the motor cortex with an emphasis on motor skill learning and execution under physiological conditions.
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Affiliation(s)
- Clément Vitrac
- Laboratoire de Neurosciences Expérimentales et Cliniques, INSERM U1084, Poitiers, France.,Laboratoire de Neurosciences Expérimentales et Cliniques, Université de Poitiers, Poitiers, France
| | - Marianne Benoit-Marand
- Laboratoire de Neurosciences Expérimentales et Cliniques, INSERM U1084, Poitiers, France.,Laboratoire de Neurosciences Expérimentales et Cliniques, Université de Poitiers, Poitiers, France
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Flik G, Dremencov E, Cremers TIHF, Folgering JHA, Westerink BHC. The role of cortical and hypothalamic histamine-3 receptors in the modulation of central histamine neurotransmission: an in vivo electrophysiology and microdialysis study. Eur J Neurosci 2011; 34:1747-55. [DOI: 10.1111/j.1460-9568.2011.07893.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Müller CP, Pum ME, Amato D, Schüttler J, Huston JP, De Souza Silva MA. The in vivo neurochemistry of the brain during general anesthesia. J Neurochem 2011; 119:419-46. [DOI: 10.1111/j.1471-4159.2011.07445.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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Yamamura S, Ohoyama K, Hamaguchi T, Kashimoto K, Nakagawa M, Kanehara S, Suzuki D, Matsumoto T, Motomura E, Shiroyama T, Okada M. Effects of quetiapine on monoamine, GABA, and glutamate release in rat prefrontal cortex. Psychopharmacology (Berl) 2009; 206:243-58. [PMID: 19575183 DOI: 10.1007/s00213-009-1601-9] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2009] [Accepted: 06/22/2009] [Indexed: 01/10/2023]
Abstract
INTRODUCTION The atypical antipsychotic drug, quetiapine (QTP), is effective in schizophrenia and mood disorders, but induces seizures compared to typical antipsychotics. METHODS To explore the mechanisms of action of QTP, we determined its effects on extracellular levels of norepinephrine, dopamine, serotonin, gamma-aminobutyric acid (GABA), and glutamate in the medial prefrontal cortex (mPFC) using microdialysis, and neuronal firing in the ventral tegmental area (VTA), locus coeruleus (LC), dorsal raphe nucleus (DRN), and mediodorsal thalamic nucleus (MTN) by telemetry in freely moving rats. RESULTS QTP (10 and 30 mg/kg, i.p.) activated neuronal firing in the VTA, LC, and MTN without affecting that in the DRN. QTP increased extracellular levels of norepinephrine, dopamine, and glutamate without affecting serotonin or GABA levels in the mPFC. The stimulatory effects of QTP on norepinephrine and dopamine were mediated by positive alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)/glutamatergic and negative GABA-mediated NMDA/glutamatergic regulation. DISCUSSION The dopaminergic terminal projecting from the VTA received inhibitory GABA-mediated NMDA/glutamatergic regulation, but not stimulatory AMPA/glutamatergic regulation. However, both dopaminergic and noradrenergic terminals from the LC received stimulatory AMPA/glutamatergic regulation from the MTN, but not inhibitory GABA-mediated NMDA/glutamatergic regulation. These findings correlating neuronal activities in nuclei with neurotransmitter release suggested that the effects of QTP on neurotransmission in the mPFC depend on activated neuronal projections located outside the mPFC. Furthermore, positive interaction between LC and MTN afferents are potentially important in the pharmacological mechanisms of neurotransmitter regulation by QTP and hint at mechanisms underlying the atypical profile of this drug for treatment of schizophrenia and as a mood stabilizer and proconvulsive agent.
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Affiliation(s)
- Satoshi Yamamura
- Department of Psychiatry, Division of Neuroscience, Graduate School of Medicine, Mie University, 2-174 Edobashi, Tsu, Mie, 514-8507, Japan
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Yamamura S, Ohoyama K, Hamaguchi T, Nakagawa M, Suzuki D, Matsumoto T, Motomura E, Tanii H, Shiroyama T, Okada M. Effects of zotepine on extracellular levels of monoamine, GABA and glutamate in rat prefrontal cortex. Br J Pharmacol 2009; 157:656-65. [PMID: 19371334 DOI: 10.1111/j.1476-5381.2009.00175.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND AND PURPOSE The atypical antipsychotic drug, zotepine, is effective in treatment of schizophrenia and acute mania, but the incidence of seizures during treatment is higher than with other antipsychotics. In addition, the mechanisms underlying the clinical actions of zotepine remain uncharacterized. EXPERIMENTAL APPROACH The effects of intraperitoneal administration of zotepine and haloperidol on the extracellular levels of noradrenaline, dopamine, 5-HT, GABA, and glutamate in the medial prefrontal cortex (mPFC) were compared. Neuronal activities induced by each drug in the ventral tegmental area (VTA), locus coeruleus (LC), dorsal raphe nucleus (DRN) and mediodorsal thalamic nucleus (MTN) were also analysed. KEY RESULTS Haloperidol did not affect extracellular neurotransmitter levels in the mPFC. In contrast, zotepine activated neuronal activities in all nuclei and increased the extracellular levels of noradrenaline, dopamine, GABA, and glutamate in the mPFC, but not 5-HT levels. The zotepine-stimulated neuronal activity in the VTA, LC, DRN and MTN enhanced the release of dopamine, noradrenaline, 5-HT, glutamate and GABA in the mPFC, although the enhanced GABAergic transmission possibly inhibited noradrenaline, dopamine and 5-HT release. The other afferent to mPFC, which releases dopamine and noradrenaline, was partially insensitive to GABAergic inhibition, but possibly received stimulatory AMPA/glutamatergic regulation from the MTN. CONCLUSIONS AND IMPLICATIONS Our results indicated that the positive interaction between prefrontal catecholaminergic transmission and AMPA/glutamatergic transmission from MTN might explain the regulatory effects of zotepine on neurotransmitter release. A mechanism is suggested to account for the pharmacological profile of this atypical antipsychotic and for its pro-convulsive action.
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Affiliation(s)
- S Yamamura
- Department of Psychiatry, Division of Neuroscience, Graduate School of Medicine, Mie University, Mie, Japan
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Huang HP, Wang SR, Yao W, Zhang C, Zhou Y, Chen XW, Zhang B, Xiong W, Wang LY, Zheng LH, Landry M, Hökfelt T, Xu ZQD, Zhou Z. Long latency of evoked quantal transmitter release from somata of locus coeruleus neurons in rat pontine slices. Proc Natl Acad Sci U S A 2007; 104:1401-6. [PMID: 17227848 PMCID: PMC1783087 DOI: 10.1073/pnas.0608897104] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The locus coeruleus (LC) harbors a compact group of noradrenergic cell bodies projecting to virtually all parts of the central nervous system. By using combined measurements of amperometry and patch-clamp, quantal vesicle release of noradrenaline (NA) was detected as amperometric spikes, after depolarization of the LC neurons. After a pulse depolarization, the average latency of amperometric spikes was 1,870 ms, whereas the latency of glutamate-mediated excitatory postsynaptic currents was 1.6 ms. A substantial fraction of the depolarization-induced amperometric spikes originated from the somata. In contrast to glutamate-mediated excitatory postsynaptic currents, NA secretion was strongly modulated by the action potential frequency (0.5-50 Hz). Somatodendritic NA release from LC upon enhanced cell activity produced autoinhibition of firing and of NA release. We conclude that, in contrast to classic synaptic transmission, quantal NA release from LC somata is characterized by a number of distinct properties, including long latency and high sensitivity to action potential frequency.
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Affiliation(s)
- H.-P. Huang
- *Institute of Neuroscience, Shanghai Institutes for the Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
- Institute of Molecular Medicine, Peking University, Beijing 100871, China
| | - S.-R. Wang
- *Institute of Neuroscience, Shanghai Institutes for the Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
- Institute of Molecular Medicine, Peking University, Beijing 100871, China
| | - W. Yao
- *Institute of Neuroscience, Shanghai Institutes for the Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
- Institute of Molecular Medicine, Peking University, Beijing 100871, China
| | - C. Zhang
- *Institute of Neuroscience, Shanghai Institutes for the Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
- Institute of Molecular Medicine, Peking University, Beijing 100871, China
| | - Y. Zhou
- *Institute of Neuroscience, Shanghai Institutes for the Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
- Institute of Molecular Medicine, Peking University, Beijing 100871, China
| | - X.-W. Chen
- *Institute of Neuroscience, Shanghai Institutes for the Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
- Institute of Molecular Medicine, Peking University, Beijing 100871, China
| | - B. Zhang
- *Institute of Neuroscience, Shanghai Institutes for the Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
- Institute of Molecular Medicine, Peking University, Beijing 100871, China
| | - W. Xiong
- *Institute of Neuroscience, Shanghai Institutes for the Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
- Institute of Molecular Medicine, Peking University, Beijing 100871, China
| | - L.-Y. Wang
- *Institute of Neuroscience, Shanghai Institutes for the Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
- Institute of Molecular Medicine, Peking University, Beijing 100871, China
| | - L.-H. Zheng
- *Institute of Neuroscience, Shanghai Institutes for the Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
- Institute of Molecular Medicine, Peking University, Beijing 100871, China
| | - M. Landry
- Institut National de la Santé et de la Recherche Médicale E358, Institut Francois Magendie, Universite Victor Segalen Bordeaux 2, 33077 Bordeaux, France
| | - T. Hökfelt
- Department of Neuroscience, Karolinska Institutet, S-171 71 Stockholm, Sweden; and
- To whom correspondence may be addressed. E-mail:
or
| | - Z.-Q. D. Xu
- Department of Neuroscience, Karolinska Institutet, S-171 71 Stockholm, Sweden; and
| | - Z. Zhou
- *Institute of Neuroscience, Shanghai Institutes for the Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
- Institute of Molecular Medicine, Peking University, Beijing 100871, China
- State Key Laboratory of Biomembrane Engineering, College of Life Sciences, Peking University, Beijing 100871, China
- To whom correspondence may be addressed. E-mail:
or
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Fernández-Pastor B, Mateo Y, Gómez-Urquijo S, Javier Meana J. Characterization of noradrenaline release in the locus coeruleus of freely moving awake rats by in vivo microdialysis. Psychopharmacology (Berl) 2005; 180:570-9. [PMID: 15717207 DOI: 10.1007/s00213-005-2181-y] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2004] [Accepted: 01/10/2005] [Indexed: 11/26/2022]
Abstract
RATIONALE The origin and regulation of noradrenaline (NA) in the locus coeruleus (LC) is unknown. OBJECTIVES The neurochemical features of NA overflow (nerve impulse dependence, neurotransmitter synthesis, vesicle storage, reuptake, alpha2-adrenoceptor-mediated regulation) were characterized in the LC. METHODS Brain microdialysis was performed in awake rats. Dialysates were analyzed for NA. RESULTS NA in the LC decreased via local infusion of Ca2+-free medium (-42+/-5%) or the sodium channel blocker tetrodotoxine (TTX) (-47+/-8%) but increased (333+/-40%) via KCl-induced depolarization. The tyrosine hydroxylase (TH) inhibitor alpha-methyl-p-tyrosine (250 mg kg(-1), i.p.) and the vesicle depletory drug reserpine (5 mg kg(-1), i.p.) decreased NA. Therefore, extracellular NA in the LC satisfies the criteria for an impulse flow-dependent vesicular exocytosis of neuronal origin. Local perfusion of the alpha2-adrenoceptor agonist clonidine (0.1-100 microM) decreased NA (E(max)=-79+/-5%) in the LC, whereas the opposite effect (E(max)=268+/-53%) was observed with the alpha2A-adrenoceptor antagonist BRL44408 (0.1-100 microM). This suggests a tonic modulation of NA release through local alpha2A-adrenoceptors. The selective NA reuptake inhibitor desipramine (DMI) (0.1-100 microM) administered into the LC increased NA in the LC (E(max)=223+/-40%) and simultaneously decreased NA in the cingulate cortex, confirming the modulation exerted by NA in the LC on firing activity of noradrenergic cells and on the subsequent NA release in noradrenergic terminals. CONCLUSION Synaptic processes underlying NA release in the LC are similar to those in noradrenergic terminal areas. NA in the LC could represent local somatodendritic release, but also the presence of neurotransmitter release from collateral axon terminals.
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Sajedianfard J, Khatami S, Semnanian S, Naghdi N, Jorjani M. In vivo measurement of noradrenaline in the locus coeruleus of rats during the formalin test: A microdialysis study. Eur J Pharmacol 2005; 512:153-6. [PMID: 15840399 DOI: 10.1016/j.ejphar.2005.02.032] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2005] [Revised: 02/16/2005] [Accepted: 02/22/2005] [Indexed: 11/26/2022]
Abstract
The locus coeruleus is involved in the regulation of the sense of pain. To demonstrate the changes in noradrenaline level in the locus coeruleus during the formalin test, a microdialysis probe was implanted into the left locus coeruleus of rats. Formalin was subcutaneously injected into the plantar surface of the right hind paw and pain ratings were recorded. The concentrations of noradrenaline and its metabolite 3-methoxy-4-hydroxyphenylethylenglycol (MHPG) were measured. The results showed an almost four-fold elevation in noradrenaline release in the early phase of the formalin test; levels return to baseline in the late phase. Levels of MHPG changed in a similar fashion.
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Affiliation(s)
- Javad Sajedianfard
- Department of Physiology, Tarbiat Modarres University, P.O. Box 14155-4838, Tehran, Iran
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Tachibana T, Utimura D, Kato H, Kubo T, Sugahara K. Extracellular norepinephrine in the medial hypothalamus increases during feeding in chicks: a microdialysis study. Comp Biochem Physiol A Mol Integr Physiol 2000; 127:331-8. [PMID: 11118942 DOI: 10.1016/s1095-6433(00)00261-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Norepinephrinergic function in the medial hypothalamus is important for the regulation of feeding behavior in chicks as well as in rats. This study was conducted to clarify the variation of extracellular norepinephrine (NE) in the medial hypothalamus, including the paraventricular nucleus (PVN) and the ventromedial hypothalamic nucleus (VMN), during feeding behavior of layer-type chicks. To measure extracellular NE and 4-hydroxy-3-methoxyphenylglycol (MHPG), a major metabolite of NE, we used microdialysis and high-pressure liquid chromatography (HPLC) with electrochemical detection. After the collection of baseline samples, food-deprived animals were allowed access to the food for 3 h. Extracellular NE significantly increased during the first hour of access to food, and then returned to baseline levels. MHPG also increased during the feeding, but its increase continued throughout the remainder of the experiment. This study suggests that the variation of NE in the medial hypothalamus may be involved in the control of feeding in layer-type chicks.
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Affiliation(s)
- T Tachibana
- Laboratory of Animal Nutrition, Department of Animal Science, Faculty of Agriculture, Utsunomiya University, 321-8505, Utsunomiya, Japan.
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Geddes JW, Chang NG, Ackley DC, Soultanian NS, McGillis JP, Yokel RA. Postmortem elevation in extracellular glutamate in the rat hippocampus when brain temperature is maintained at physiological levels: implications for the use of human brain autopsy tissues. Brain Res 1999; 831:104-12. [PMID: 10411988 DOI: 10.1016/s0006-8993(99)01403-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Postmortem alterations in the neuronal cytoskeleton resemble some aspects of the cytoskeletal disruption associated with neurodegenerative disorders, and are also similar to those observed following ischemia and produced by excitotoxins in vivo and in vitro. This suggests the involvement of excitotoxic mechanisms during the postmortem interval. The purpose of this study was to determine if extracellular levels of glutamate are elevated postmortem. Extracellular levels of GABA and taurine were also monitored using in vivo microdialysis. These three amino acids were analyzed using high-performance liquid chromatography. When postmortem rat brain temperature cooled rapidly to near room temperature, dialysate concentrations of glutamate were not increased in the hippocampal CA1 region during a 2-h postmortem interval, although increased extracellular levels of GABA and taurine were observed. In contrast, maintenance of brain temperature at 37 degrees C resulted in a 12-to-40 fold elevation in extracellular glutamate levels 20-120 min postmortem. In addition, the elevation in dialysate taurine concentration was greater than that observed in rats in which postmortem brain temperature was not maintained. Excitatory amino acid antagonists, NBQX (2, 3-dihydroxy-6-nitro-7-sulfamoyl-benzo(F)quinoxaline) and MK-801 (dizocilpine, (+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cylohepten-5, 10-imine hydrogen maleate blocked the additional elevation in taurine associated with maintaining brain at 37 degrees C, but had less robust effects against glutamate and GABA release. The results indicate that extracellular concentrations of glutamate, taurine and GABA increase in postmortem rat brain when physiologic temperatures are maintained, but that these increases are blunted when brain temperature decreases. After death, the human brain cools much more slowly than does the rat brain. Therefore, extracellular glutamate levels are likely to increase in the postmortem human brain and may contribute to excitotoxic neuronal damage occurring in the interval between death and autopsy.
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Affiliation(s)
- J W Geddes
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40536-0230, USA.
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Gobert A, Rivet JM, Audinot V, Newman-Tancredi A, Cistarelli L, Millan MJ. Simultaneous quantification of serotonin, dopamine and noradrenaline levels in single frontal cortex dialysates of freely-moving rats reveals a complex pattern of reciprocal auto- and heteroreceptor-mediated control of release. Neuroscience 1998; 84:413-29. [PMID: 9539213 DOI: 10.1016/s0306-4522(97)00565-4] [Citation(s) in RCA: 162] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
In the present study, a novel and exceptionally sensitive method of high-performance liquid chromatography coupled to coulometric detection, together with concentric dialysis probes, was exploited for an examination of the role of autoreceptors and heteroceptors in the modulation of dopamine, noradrenaline and serotonin levels in single samples of the frontal cortex of freely-moving rats. The selective D3/D2 receptor agonist, CGS 15855A [(+/-)-trans-1,3,4,4a,5,10b-hexahydro-4-propyl-2H-[1]benzopyrano[3 ,4-b]-pyridin-9-ol], and antagonist, raclopride, respectively decreased (-50%) and increased (+60%) levels of dopamine without significantly modifying those of serotonin and noradrenaline. The selective alpha2-adrenergic receptor agonist, dexmedetomidine, markedly decreased noradrenaline levels (-100%) and likewise suppressed those of serotonin and dopamine by -55 and -45%, respectively. This effect was mimicked by the preferential alpha2-adrenergic receptor agonist, guanabenz (-100%, -60% and -50%). Furthermore, the alpha2-adrenergic receptor antagonist, RX 821,002 [2(2-methoxy-1,4-benzodioxan-2-yl)-2-imidazoline], and the preferential alpha2A-adrenergic receptor antagonist, BRL 44408 [2-(2H-(1-methyl-1,3-dihydroisoindole)methyl)-4,5-dihydroimidaz ole], both evoked a pronounced elevation in levels of noradrenaline (+212%, +109%) and dopamine (+73%, +85%). In contrast, the preferential alpha(2B/2C)-adrenergic receptor antagonist, prazosin, did not modify noradrenaline and dopamine levels. RX 821,002 and BRL 44408 did not significantly modify levels of serotonin, whereas prazosin decreased these levels markedly (-55%), likely due to its alpha1-adrenergic receptor antagonist properties. The selective serotonin-1A receptor agonist, 8-hydroxy-2-(di-n-propylamino)-tetralin (8-OH-DPAT), reduced serotonin levels (-65%) and increased those of dopamine and noradrenaline by +100%), and +175%, respectively. The selective serotonin-1A antagonist, WAY 100,635 [N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-N-(2-pyridinyl)cyclo- hexanecarboxamide], which had little affect on monoamine levels alone, abolished the influence of 8-OH-DPAT upon serotonin and dopamine levels and significantly attenuated its influence upon noradrenaline levels. Finally, the selective serotonin-1B agonist, GR 46611 [3-[3-(2-dimethylaminoethyl)-1H-indol-5-yl]-N-(4-methoxybenzyl)acrylamid e], decreased serotonin levels (-49%) and the serotonin-1B antagonist, GR 127,935 [N-[4-methoxy-3-(4-methylpiperazin-1-yl)phenyl]-2'-methyl-4'-(5-me thyl-1,2,4-oxadiazol-3-yl)-biphenyl-4-carboxamide], which did not significantly modify serotonin levels alone, abolished this action of GR 46611. Levels of dopamine and noradrenaline were not affected by GR 46611 or GR 127,935. In conclusion, there is a complex pattern of reciprocal autoreceptor and heteroceptor control of monoamine release in the frontal cortex. Most notably, activation of alpha2-adrenergic receptors inhibits the release of noradrenaline, dopamine and serotonin in each case, while stimulation of serotonin-1A receptors suppresses serotonin, yet facilitates noradrenaline and dopamine release. In addition, dopamine D2/D3 autoreceptors restrain dopamine release while (terminal-localized) serotonin-1B receptors reduce serotonin release. Control of serotonin release is expressed phasically and that of noradrenaline and dopamine release tonically.
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Affiliation(s)
- A Gobert
- Institut de Recherches Servier, Psychopharmacology Department, Croissy-sur-Seine, France
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Sarre S, Smolders I, Thorré K, Ebinger G, Michotte Y. Biotransformation of locally applied precursors of dopamine, serotonin and noradrenaline in striatum and hippocampus: a microdialysis study. J Neural Transm (Vienna) 1998; 104:1215-28. [PMID: 9503267 DOI: 10.1007/bf01294722] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In vivo microdialysis in freely moving rats was used to study the biotransformation, consisting primarily of decarboxylation by aromatic amino acid decarboxylase (AAAD), of the precursors L-3,4-dihydroxyphenylalanine (L-DOPA), L-5-hydroxytryptophan (L-5HTP), and L-threo-3,4-dihydroxyphenylserine (L-threo-DOPS) on extracellular levels of dopamine (DA), serotonin (5HT) and noradrenaline (NA), respectively. The precursors were administered locally through the microdialysis probe into the striatum and into the hippocampus. The different transmitter systems were compared with respect to the ability of the precursors to elevate extracellular levels of their associated transmitter. The basal extracellular concentrations of NA and DA were found to be tetrodotoxin (TTX, a blocker of fast sodium channels) sensitive in striatum and hippocampus, indicating the neuronal origin of the measured transmitters. The extracellular concentrations of 5HT (in hippocampus) were only 60% TTX-sensitive. L-DOPA and L-5HTP showed to be effective precursors of DA and 5HT, respectively, although their formation profile was quite different. The L-DOPA-induced increase in extracellular DA was large and short-lasting, while the L-5HTP-induced increase in 5HT was slower and less pronounced. The relative increase in extracellular DA or 5HT was more pronounced in the brain region where their baseline values were lower, but the absolute amount of transmitter formed from their precursor was similar in both brain regions. L-threo-DOPS was a poor precursor for NA and also failed to influence extracellular DA in striatum, questioning its use in the treatment of freezing gait in late stages of Parkinson's disease.
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Affiliation(s)
- S Sarre
- Department of Pharmaceutical Chemistry and Drug Analysis, Pharmaceutical Institute, University Hospital, Vrije Universiteit, Brussel, Belgium
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Cremers TI, Teisman AC, van Gilst WH, Westerink BH. Use of microdialysis for monitoring sympathetic and parasympathetic innervation of heart in conscious rats. THE AMERICAN JOURNAL OF PHYSIOLOGY 1997; 273:H2850-6. [PMID: 9435623 DOI: 10.1152/ajpheart.1997.273.6.h2850] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A microdialysis method was developed to sample norepinephrine and acetylcholine from the heart of freely moving rats. A flexible dialysis fiber (length 14 mm), with a copper wire inserted inside, was implanted into the heart. Extracellular norepinephrine was detectable for at least 72 h after implantation. Basal output levels 24 h after surgery were 140 pg/ml when corrected for in vitro recovery. Evidence was provided that the major part of norepinephrine in dialysates is derived from local neurotransmission. Acetylcholine was only detectable in cardiac dialysates when an esterase inhibitor was infused. Corrected basal output levels 24 h after surgery were 223 pg/ml when neostigmine was coinfused in a concentration of 100 mumol/l. In addition, the presence of local muscarinic autoreceptors on cholinergic neurons in the heart was shown. It is concluded that microdialysis is a reliable method that can be used to study the innervation of the heart in subchronic preparations in freely moving rats.
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Affiliation(s)
- T I Cremers
- Department of Medicinal Chemistry, Faculty of Medicine, University of Groningen, The Netherlands
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Van Gaalen M, Kawahara H, Kawahara Y, Westerink BH. The locus coeruleus noradrenergic system in the rat brain studied by dual-probe microdialysis. Brain Res 1997; 763:56-62. [PMID: 9272828 DOI: 10.1016/s0006-8993(97)00416-2] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A dual-probe microdialysis technique was applied to the locus coeruleus (LC) and prefrontal cortex (PFC) of the brain of conscious rats. One probe was implanted close to the LC and was used to apply receptor-specific compounds by retrograde microdialysis. The effects of the LC infusions were recorded by a sampling noradrenaline by a second probe that was implanted in the ipsilateral prefrontal cortex. Infusion of sodium channel blocker tetrodotoxin (1 microM; 90 min) into the LC decreased extracellular noradrenaline in the PFC to approximately 20% of control values. Infusion of alpha2-adrenoceptor agonist clonidine (100 microM, infused during 15 or 45 min) near to the LC, decreased extracellular noradrenaline in the PFC to 35 and 20% of controls, respectively. These results indicate that > 80% of the extracellular levels of noradrenaline in the PFC is derived from LC innervation, and confirms the importance of alpha2-autoreceptors on noradrenergic neurons in the LC. Infusion of the cholinergic receptor agonist, carbachol (100 microM, 45 min) near to the LC increased extracellular noradrenaline in the PFC to approximately 150% of controls. Infusions of the excitatory amino-acid agonists NMDA and kainate into the LC caused marked increases in extracellular noradrenaline in the PFC to 240 and 200% of controls, respectively. The experiments with clonidine, carbachol, NMDA and kainate were repeated in anesthetized rats. Clonidine and carbachol were similarly effective as in conscious animals but the effects of NMDA and kainate on extracellular noradrenaline in the PFC were clearly suppressed: 145 and 130% of controls, respectively. These results suggest that increased arousal or behavioural activation might have contributed to the increases in extracellular noradrenaline that was seen after infusion of the glutamate agonists. These results also provide evidence for localization of cholinergic-, NMDA-, non-NMDA-receptor on noradrenergic neurons in the LC. Finally it is concluded that dual-probe microdialysis is a useful method to further investigate the pharmacology of LC-noradrenergic neurons. Carbachol and clonidine are suitable tools for a rapid and reversible stimulation or inhibition, respectively, of noradrenergic LC neurons.
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Affiliation(s)
- M Van Gaalen
- Department of Medicinal Chemistry, University Center for Pharmacy, University of Groningen, The Netherlands
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15
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Robert F, Bert L, Lambás-Señas L, Denoroy L, Renaud B. In vivo monitoring of extracellular noradrenaline and glutamate from rat brain cortex with 2-min microdialysis sampling using capillary electrophoresis with laser-induced fluorescence detection. J Neurosci Methods 1996; 70:153-62. [PMID: 9007754 DOI: 10.1016/s0165-0270(96)00113-6] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The measurement of neurotransmitters by capillary electrophoresis (CE) has emerged as a reliable and sensitive method for microdialysis sample analysis. This paper describes a method which employs laser-induced fluorescence detection (LIFD) of catecholamines and excitatory amino acid derivatives formed after reaction with naphthalene-2,3-dicarboxaldehyde. On-line derivatization of very small volumes of microdialysis samples (500 nl) is developed before two off-line analyses (total run time of less than 10 min) are performed to detect derivatives of catecholamines and excitatory amino acids formed in each sample. High microdialysis temporal resolution is reached (2-min fractions) for the simultaneous monitoring of noradrenaline (NA) and glutamate concentrations from rat brain cortex microdialysates. The system performance is evaluated and pharmacological characterization of the determination of NA in cortical dialysates by CE-LIFD is reported.
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Affiliation(s)
- F Robert
- Laboratoire de Neuropharmacologie et Neurochimie, INSERM CJF 95-06, Lyon, France.
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16
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Pan WH, Lai YJ. Anesthetics decreased the microdialysis extraction fraction of norepinephrine but not dopamine in the medial prefrontal cortex. Synapse 1995; 21:85-92. [PMID: 8525466 DOI: 10.1002/syn.890210112] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We evaluated the effects of chloral hydrate and pentobarbital sodium on the basal extracellular concentrations of dopamine (DA) and norepinephrine (NA) as well as their in vivo extraction fraction (relative recovery) at the medial prefrontal cortex (mPFC) in rats by using zero-net flux microdialysis method. Adult, male Sprague-Dawley rats anesthetized with either chloral hydrate (400 mg/kg, i.p., with 80 mg/kg i.v. supplements) or pentobarbital sodium (50 mg/kg, i.p., with 10 mg/kg i.v. supplements) were used as treatment groups. Conscious rats were used as a control group. The basal extracellular concentration and in vivo recovery of DA in the conscious group were 2.38 +/- 0.70 nM and 41 +/- 6%. In comparison with the chloral hydrate group (1.51 +/- 0.55 nM and 41 +/- 9%) and the pentobarbital sodium group (2.81 +/- 1.20 nM and 42 +/- 4%), there were no significant effects of anesthesia on the basal extracellular concentration and the in vivo recovery of DA at the mPFC. Additionally, the basal extracellular concentration and the in vivo recovery of NA in the conscious group were 1.59 +/- 0.37 nM and 51 +/- 8%. There also were no significant differences of the basal extracellular concentration of NA among these three groups (chloral hydrate group: 4.38 +/- 1.39 nM; pentobarbital group: 3.67 +/- 0.90 nM). However, the conscious group had a higher in vivo recovery than the two anesthetized groups (chloral hydrate group: 16 +/- 2%; pentobarbital group: 27 +/- 5%).(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- W H Pan
- Institute of Pharmacology, School of Life Sciences, National Yang-Ming University, Taipei, Taiwan, Republic of China
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17
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French N, Lalies MD, Nutt DJ, Pratt JA. Idazoxan-induced reductions in cortical glucose use are accompanied by an increase in noradrenaline release: complementary [14C]2-deoxyglucose and microdialysis studies. Neuropharmacology 1995; 34:605-13. [PMID: 7566496 DOI: 10.1016/0028-3908(95)00031-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The autoradiographic [14C]2-deoxyglucose procedure was used to map function-related alterations in local cerebral glucose use following acute administration of the alpha 2-adrenoceptor antagonist, idazoxan (0.3-3 mg kg-1 s.c.). The most prominent feature of the results obtained was the significant reduction in glucose use in certain locus coeruleus projection areas. Thus, in various cortical, hippocampal and thalamic regions, as well as structures involved in auditory and visual function, idazoxan administration was associated with a 13-20% decrease in glucose use. In a complementary microdialysis study, the effect of idazoxan on extracellular noradrenaline levels in the frontal cortex of rats, manipulated in the same fashion as during the [14C]2-deoxyglucose procedure (i.e. following the application of surgery and partial restraint), was examined. Both surgery and restraint were associated with a modest but significant increase in basal noradrenaline release (+31% and +26%, respectively). Subsequent administration of idazoxan (3 mg kg-1 s.c.) evoked a further increase in noradrenaline release, the magnitude of which was the same as that observed following its administration to freely-moving rats (+113%). These combined data suggest that idazoxan-induced reductions in cerebral glucose use, at least in the frontal cortex, may occur as a consequence of the increase in noradrenaline release. In addition, it appears that surgery and partial restraint do not alter alpha 2-adrenoceptor tone in the frontal cortex.
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Affiliation(s)
- N French
- Department of Physiology and Pharmacology, University of Strathclyde, Glasgow, U.K
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18
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Dalley JW, Stanford SC. Contrasting effects of the imidazol(in)e alpha 2-adrenoceptor agonists, medetomidine, clonidine and UK 14,304 on extraneuronal levels of noradrenaline in the rat frontal cortex: evaluation using in vivo microdialysis and synaptosomal uptake studies. Br J Pharmacol 1995; 114:1717-23. [PMID: 7599940 PMCID: PMC1510391 DOI: 10.1111/j.1476-5381.1995.tb14962.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
1. In vivo microdialysis in halothane-anaesthetized rats and synaptosomal [3H]-noradrenaline uptake studies in vitro were used to evaluate the effects of imidazole (medetomidine) and imidazoline (clonidine and UK 14,304) alpha 2-adrenoceptor agonists on extraneuronal levels of noradrenaline in the frontal cortex. 2. Levels of noradrenaline in the dialysate were increased by a depolarizing concentration of K+ (60 mM for 20 min) and substantially attenuated by reducing Ca2+ supply in the perfusate. These results suggest that spontaneous efflux of noradrenaline in the cortex is regulated predominantly by cation-dependent exocytotic mechanisms. 3. At a low perfusion concentration (0.5 microM), medetomidine, clonidine and UK 14,304 all reduced the level of noradrenaline in cortical dialysates. Continuous perfusion of the selective alpha 2-adrenoceptor antagonist, atipamezole (0.5 microM) caused a sustained increase in noradrenaline efflux and reversed the inhibitory effects of medetomidine. All these changes are consistent with drug actions at presynaptic alpha 2-adrenoceptors. 4. Higher concentrations of medetomidine (5-50 microM), but not clonidine or UK 14,304, evoked a non-desensitizing increase in noradrenaline efflux. This effect was not antagonized by 0.5 microM atipamezole. 5. The tricyclic noradrenaline reuptake inhibitor, desmethylimipramine (0.5-50 microM), increased noradrenaline efflux in a concentration-dependent manner. 6. The specific uptake of [3H]-noradrenaline into cortical synaptosomes was inhibited by medetomidine and desmethylimipramine with IC50 values of approximately 7 microM and 8 microM respectively. Neither clonidine nor UK 14,304 inhibited [3H]-noradrenaline uptake. 7. These results indicate that micromolar concentrations of the selective alpha2-adrenoceptor agonist,medetomidine, can augment extraneuronal levels of noradrenaline in the rat frontal cortex; this effect seems to involve an inhibition of noradrenaline reuptake rather than an action at alpha2-adrenoceptors.
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Affiliation(s)
- J W Dalley
- Department of Pharmacology, University College London
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19
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Morris MJ, Hastings JA, Pavia JM. Catecholamine release in the rat hypothalamic paraventricular nucleus in response to haemorrhage, desipramine and potassium. Brain Res 1994; 665:5-12. [PMID: 7882018 DOI: 10.1016/0006-8993(94)91145-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
In vivo microdialysis and HPLC were used to measure catecholamine release in the rat hypothalamic paraventricular nucleus (PVN) during haemorrhage. The effects of noradrenaline uptake blockade with 1 microM desipramine (DMI) and a depolarising concentration of potassium (100 mM) through the probe were also examined. Dialysis probes implanted in the PVN of urethane anesthetised rats were perfused with modified Ringer solution at 1.1 microliter/min. Thirty minute collections were analysed for DOPA, noradrenaline, DOPAC, HVA and 5-HIAA. Basal concentrations, in the absence of DMI, were: DOPA 203.6 +/- 44.0 pg/ml, noradrenaline 128.0 +/- 20.4 pg/ml; DOPAC 5.6 +/- 0.7, HVA 5.1 +/- 2.2 and 5-HIAA 87.2 +/- 17.8 ng/ml. Basal noradrenaline was doubled in the presence of DMI while basal and stimulated DOPA, DOPAC, HVA and 5-HIAA were not affected by DMI. Haemorrhage resulted in a significant noradrenaline release (48% over resting levels) in the presence of DMI (n = 10, P < 0.05); in the absence of DMI, a smaller and non-significant increase (30% over basal levels) was observed. Potassium-induced depolarisation caused a significant two- and four-fold increase in noradrenaline release (P < 0.001), with decreases in the dopamine metabolites DOPAC (31%, 44%) and HVA (35%, 28%), and the serotonin metabolite, 5-HIAA (41%, 33%), in the presence and absence of DMI, respectively. The catecholamine precursor DOPA did not vary throughout either experiment. The results indicate that haemorrhage induces a 48% increase in noradrenaline release in the rat PVN which provides evidence for a role of noradrenergic projections to the PVN in cardiovascular control.
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Affiliation(s)
- M J Morris
- Faculty of Science and Technology, School of Biological and Chemical Sciences, Deakin University, Geelong, Victoria, Australia
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20
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Florin SM, Kuczenski R, Segal DS. Regional extracellular norepinephrine responses to amphetamine and cocaine and effects of clonidine pretreatment. Brain Res 1994; 654:53-62. [PMID: 7982098 DOI: 10.1016/0006-8993(94)91570-9] [Citation(s) in RCA: 99] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Microdialysis in behaving animals was used to characterize the hippocampus (HP) and prefrontal cortex (PFC) norepinephrine (NE) responses to amphetamine (AMPH) and cocaine (COC). NE exhibited regionally similar dose- and time-dependent increases to each drug. However, peak NE concentrations were approximately 2-fold greater at behaviorally similar doses of AMPH compared with COC. To examine the role of noradrenergic impulse flow in the mechanism(s) by which these stimulants enhance extracellular NE, groups of animals were pretreated with the alpha 2 autoreceptor agonist, clonidine (CLON), prior to stimulant administration. CLON (50 micrograms/kg) administration completely blocked the NE response to both 20 and 30 mg/kg COC. By contrast, CLON decreased the NE response to 0.5 mg/kg AMPH by 75%, but became progressively less effective on the response as the dose was increased to 1.75 and 5.0 mg/kg. CLON also had no effect on the caudate dopamine responses to either AMPH or COC, consistent with the presumed specificity of this drug for alpha 2 receptors and suggesting the absence of any significant pharmacokinetic interactions. These results indicate that COC acts an uptake blocker at NE-containing neurons and suggest that AMPH increases extracellular NE through two consequences of its interaction with the neuronal transport carrier: (1) reuptake blockade which predominates at lower doses; and (2) release which becomes more prevalent at higher doses. Behavioral analyses revealed effects of CLON which varied as a function of stimulant and dose.
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Affiliation(s)
- S M Florin
- Psychiatry Department (0603), University of California at San Diego School of Medicine, La Jolla 92093-0603
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21
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van Veldhuizen MJ, Feenstra MG, Boer GJ. Effects of neonatal exposure to clonidine on basal and activated central noradrenaline metabolism and in vivo overflow. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 1994; 79:275-82. [PMID: 7955326 DOI: 10.1016/0165-3806(94)90132-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The occurrence of persistent effects of chronic neonatal exposure to the alpha 2-adrenoceptor agonist clonidine was investigated by determination of tissue concentrations of monoamines and metabolites and in vivo overflow of noradrenaline and its metabolites, in various rat brain regions during adulthood. Rat pups were treated with clonidine from postnatal day 10-20 and all measurements were carried out between postnatal day 40 and 58. Tissue concentrations of monoamines and metabolites of the early clonidine-treated rats did not differ significantly from the control group. A challenge with yohimbine did not reveal altered responses of monoaminergic systems, except for the failure of an increased serotonergic activity in the medulla pons. In vivo microdialysis measurements revealed an elevated basal extracellular noradrenaline level in amygdala, but not in frontal cortex and hippocampus. Pharmacological challenge in vivo with idazoxan did not reveal differences between clonidine- and saline-exposed rats. These results confirm previous findings that continuous activation of alpha 2-adrenoceptors during a particular period of rat brain development may result in long-lasting but small changes in monoaminergic activity. However, these alterations are not very consistent and may depend on the parameter chosen to reflect monoaminergic activity and are not revealed more clearly by activating (challenging) the noradrenaline system with alpha2-adrenoceptor antagonists.
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Affiliation(s)
- M J van Veldhuizen
- Graduate School Neurosciences Amsterdam, Netherlands Institute for Brain Research
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22
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Smith SE, Sharp T. An investigation of the origin of extracellular GABA in rat nucleus accumbens measured in vivo by microdialysis. J Neural Transm (Vienna) 1994; 97:161-71. [PMID: 7873125 DOI: 10.1007/bf01277951] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
GABA transmission in the nucleus accumbens is believed to play a central role in motivational processes and the expression of psychostimulant drug action. Here we report measurements of extracellular GABA in nucleus accumbens of the rat and investigate its origin. Extracellular GABA was detected using microdialysis in combination with a novel HPLC-based assay. In the awake rat, GABA in the microdialysates (1) increased 10-fold following perfusion with 0.5 mM nipecotic acid, a GABA releasing agent and uptake blocker, (2) increased 7-fold following local perfusion with 50 mM KCl, (3) decreased 50% following perfusion with tetrodotoxin, (4) decreased 50% following perfusion with a Ca(2+(-free medium and (5) decreased 40% following perfusion with high (12.5 mM) MgCl. Finally, in the anaesthetized rat, GABA in the microdialysates decreased 50% following i.p. injection of 100 mg/kg 3-mercaptoproprionic acid, a GABA synthesis inhibitor. We conclude that GABA in microdialysates from nucleus accumbens of the rat (awake) responds appropriately to selected pharmacological agents and derives at least in part (50%) from neurones.
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Affiliation(s)
- S E Smith
- University Department of Clinical Pharmacology, Radcliffe Infirmary, Oxford, United Kingdom
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23
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van Veldhuizen MJ, Feenstra MG, Botterblom MH, Boer GJ. Increased alpha 2-adrenoceptor mediated regulation of adult rat brain noradrenaline overflow after chronic neonatal exposure to propranolol; a microdialysis study. Brain Res 1994; 646:19-25. [PMID: 8055338 DOI: 10.1016/0006-8993(94)90053-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Direct and persistent effects of chronic neonatal administration of the beta-adrenoceptor antagonist propranolol on brain noradrenergic activity were investigated by measuring tissue concentrations of noradrenaline and its metabolites and in vivo overflow of noradrenaline during adulthood. Rat pups were chronically treated with propranolol from postnatal day 1 to day 10. Determination of monoamine metabolism after the last injection showed an increase in noradrenaline metabolism in frontal cortex, limbic system and hippocampus of propranolol-exposed rats, but 47 days after this last injection it was apparent that these effects were not long-lasting. Moreover, basal noradrenaline overflow in vivo in the hippocampus of 40-55 day-old propranolol-exposed rats did not differ from that in controls. However, the regulation of noradrenaline release seemed to have been altered, since a pharmacological challenge with the alpha 2-adrenoceptor antagonist idazoxan induced an enhanced increase in the in vivo noradrenaline overflow in propranolol-exposed rats compared to controls. It is suggested that the neonatal beta-blockade induced a supersensitivity of the presynaptic alpha 2-adrenoceptor. The precise mechanism underlying this effect has to be elucidated.
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Affiliation(s)
- M J van Veldhuizen
- Graduate School Neurosciences, Amsterdam, Netherlands Institute for Brain Research
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24
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Thomas DN, Post RM, Pert A. Focal and systemic cocaine differentially affect extracellular norepinephrine in the locus coeruleus, frontal cortex and hippocampus of the anaesthetized rat. Brain Res 1994; 645:135-42. [PMID: 8062076 DOI: 10.1016/0006-8993(94)91646-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The purpose of this study was to characterize and compare the effects of cocaine on norepinephrine (NE) overflow in the forebrain and somatodendritic regions of anaesthetized rats with microdialysis. Intraperitoneal injections of cocaine (20 mg/kg) failed to increase NE overflow in the hippocampus and the frontal cortex but did elevate NE in the region of the locus coeruleus. Focal application of cocaine (1-100 microM) via the dialysis probe into the region of the locus coeruleus also produced a concentration dependent elevation of extracellular NE. In the terminal regions the application of focal cocaine (1-100 microM) showed a differential effect, with a concentration dependent increase in extracellular NE in the hippocampus, whilst in the frontal cortex only the highest concentration of cocaine (100 microM) elevated extracellular NE. The regional differences seen following focal applications in this study may be related to differences in transporter function in the three brain areas or to differences in the affinity for cocaine. The inability of systematically administered cocaine to increase hippocampal and cortical NE is probably related to its predominant actions in the somatodendritic region.
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Affiliation(s)
- D N Thomas
- Biological Psychiatry Branch, National Institute of Mental Health, Bethesda, MD 20892
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25
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Gazzara RA, Andersen SL. Calcium dependency and tetrodotoxin sensitivity of neostriatal dopamine release in 5-day-old and adult rats as measured by in vivo microdialysis. J Neurochem 1994; 62:1741-9. [PMID: 8158124 DOI: 10.1046/j.1471-4159.1994.62051741.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The calcium dependency and tetrodotoxin sensitivity of extracellular dopamine levels were assessed by microdialysis in the neostriatum of 5-day-old rat pups and were compared with those obtained in adult rats. The removal of calcium from the dialysate reduced spontaneous levels of extracellular dopamine to 20% of normal in the 5-day-old pups and to 10% of normal in the adults. Calcium-free dialysate also decreased potassium-evoked dopamine release to approximately 20% of baseline in both ages. Furthermore, the addition of tetrodotoxin to the dialysate decreased spontaneous levels of extracellular dopamine to 10% of baseline in both ages. The effects of calcium removal and the addition of tetrodotoxin on extracellular levels of the dopamine metabolite 3,4-dihydroxyphenylacetic acid were less pronounced. The results of this study demonstrate that extracellular levels of dopamine sampled by microdialysis in rats as young as 5 days of age are both calcium dependent and tetrodotoxin sensitive; thus, they are derived from neuronal activity and not from injury caused by acute implantation of the probe. Other age-related differences support the hypothesis that dopamine release and turnover is greater in immature rats and may represent a form of compensation for incomplete dopamine nerve terminal ingrowth.
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Affiliation(s)
- R A Gazzara
- Department of Psychology, State University of New York at Binghamton, New York
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van Veldhuizen MJ, Feenstra MG, Boer GJ. Regional differences in the in vivo regulation of the extracellular levels of noradrenaline and its metabolites in rat brain. Brain Res 1994; 635:238-48. [PMID: 7909716 DOI: 10.1016/0006-8993(94)91445-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Microdialysis was used to determine extracellular levels of both noradrenaline and its metabolites in several brain regions of rats under basal conditions and in response to drugs selective for the alpha 2-adrenoceptor to study regional differences in the regulation of noradrenaline overflow. Basal overflow of noradrenaline was about 1.3 fmol/min in frontoparietal cortex, amygdala and hippocampus and in the medial prefrontal cortex 2.4 fmol/min was measured, whereas the overflow of the noradrenaline metabolites 3,4-dihydroxyphenylglycol and 3-methoxy-4-hydroxyphenylglycol was 10-fold higher. After correction for recovery and membrane length no regional differences in the basal overflow of noradrenaline (NA) were found. There were, however, regional differences in the drug-induced effects: locally applied moxonidine decreased extracellular noradrenaline stronger in the frontoparietal cortex than in the medial prefrontal cortex. The increase in noradrenaline overflow caused by idazoxan (10(-4) M) was stronger in frontoparietal cortex than in amygdala and hippocampus. The metabolites were also generally decreased by moxonidine and increased by idazoxan, although less markedly. The present study shows that the regulation of noradrenaline overflow by the presynaptic alpha 2-autoreceptor was stronger in cortical regions than in amygdala and hippocampus. In those latter regions the uptake mechanism probably plays a relatively more important role in the regulation of noradrenaline overflow.
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Affiliation(s)
- M J van Veldhuizen
- Graduate School Neurosciences Amsterdam, Netherlands Institute for Brain Research
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27
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Abstract
Noradrenaline (NA) release in the rat lumbar spinal cord (L3-4) in response to variable intensity, selective stimulation of large (A-beta), small myelinated (A-delta), and unmyelinated (C) afferent fibers was examined by in vivo microdialysis with high performance liquid chromatography and electrochemical detection. Application of 100 mM K+ solution via the dialysis probe increased NA in the dialysate. Thoracic segment transection rostral to the probe depressed the NA level. Transcutaneous stimulation of peripheral nerves had the following effects: 1) High intensity stimulation of afferent A-delta or C fibers increased spinal NA release, which was decreased by thoracic spinal cord transection. 2) Stimulation of afferent A-beta or A-delta fibers at low intensity did not affect the NA level. 3) High intensity stimulation of afferent A-beta fibers depressed NA release in half of the trials. Results indicate that many NA-containing nerve terminals that innervate the lumbar spinal cord originate from supraspinal structures. Somatic neural inputs from afferent C fibers and high-threshold A-delta, but not A-beta nor low-threshold A-delta fibers, activate the descending NA system and release the NA in the spinal cord. The descending NA system may participate in antinociception.
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Affiliation(s)
- D S Men
- Department of Physiology, Showa University School of Dentistry, Tokyo, Japan
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28
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Takahashi A, Ikarashi Y, Ishimaru H, Maruyama Y. Dopamine output upon death reflects intraneuronal aspects while alive: accumulation of releasable dopamine during tetrodotoxin perfusion. Neurosci Res 1993; 18:45-51. [PMID: 8134019 DOI: 10.1016/0168-0102(93)90104-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Intraneuronal and extracellular dopamine (DA) metabolism in rat striatum during inhibition of neurotransmission processes by tetrodotoxin (TTX) perfusion was examined by analysis of the striatal DA content and the amount of initial post-mortem DA output. In spite of there being an excess amount of DA already present in the striatum, the contents of DA and its metabolites were increased time-dependently by TTX perfusion through a microdialysis membrane. A massive increase in extracellular level of DA occurred immediately after death. The amount of the post-mortem DA output was further increased in proportion to the preceding TTX perfusion time. The ratio of the amount of post-mortem DA output to the striatal DA content was also increased by previous perfusion with TTX. Verapamil, a Ca2+ channel blocker, delayed the appearance of the peak of the DA output. These results suggest that releasable DA accumulates in neurons during TTX perfusion, and that the early part of the DA output upon death reflects intraneuronal aspects of DA metabolism while the animal is alive.
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Affiliation(s)
- A Takahashi
- Department of Neuropsychopharmacology (Tsumura), Gunma University School of Medicine, Japan
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29
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van Veldhuizen MJ, Feenstra MG, Heinsbroek RP, Boer GJ. In vivo microdialysis of noradrenaline overflow: effects of alpha-adrenoceptor agonists and antagonists measured by cumulative concentration-response curves. Br J Pharmacol 1993; 109:655-60. [PMID: 8102934 PMCID: PMC2175629 DOI: 10.1111/j.1476-5381.1993.tb13623.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
1. The purpose of the present study was to compare the effects of several alpha-adrenoceptor agonists and antagonists on cerebral cortical overflow of endogenous noradrenaline (NA) in freely moving rats. One or two days after the implantation of transcerebral dialysis tubes in the frontoparietal cortex, extracellular NA levels were monitored on-line with high performance liquid chromatography and electrochemical detection. The drugs were applied locally via the dialysis membrane, and effects on NA overflow were determined in cumulative concentration-response curves. 2. The average basal cortical NA overflow of all experiments was 0.25 pg min-1. The alpha 2-adrenoceptor agonists caused a concentration-dependent decrease in NA levels. UK-14,304 was the most potent and B-HT 933 the least potent agonist. The maximal decrease in NA overflow was to 10-15% of control levels after UK-14,304 or moxonidine, to 30% after clonidine and to 50% after B-HT 933 administration. Continuous activation of the presynaptic alpha 2-adrenoceptor with 10(-6) M UK-14,304 caused a decrease in NA levels to 40-50% of basal levels. This decrease was reached within 1 h and remained stable for the entire 3 h measurement period. The alpha 1-adrenoceptor agonists, phenylephrine and methoxamine, induced an increase in NA levels to 225% and 300%, respectively, at a concentration of 10(-3) M. 3. Local application of alpha 2-adrenoceptor antagonists caused an increase in NA levels, with idazoxan being more potent than piperoxan. Yohimbine did not cause any significant change. 4. All drugs used in these in vivo experiments had in vitro recoveries across the dialysis membrane between 10 and 20%. 5. We conclude that microdialysis with local drug application is suitable for the comparison of the pharmacological effects of drugs with affinity for alpha-adrenoceptors on cortical NA overflow in vivo,provided that the passage across the membrane is equal for the different drugs.
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Affiliation(s)
- M J van Veldhuizen
- Graduate School Neurosciences Amsterdam, Netherlands Institute for Brain Research
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30
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Mitchell K, Adams RN. Comparison of the effects of voltage-sensitive calcium channel antagonism on the electrically stimulated release of dopamine and norepinephrine in vivo. Brain Res 1993; 604:349-53. [PMID: 8457864 DOI: 10.1016/0006-8993(93)90390-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
IN vivo electrochemistry was used to monitor the effects of several voltage-sensitive calcium channel (VSCC) antagonists (e.g. divalent metal ions, diltiazem and omega-conotoxin GVIA (omega-CT) on the electrically evoked release of dopamine (DA) in the striatum and norepinephrine (NE) in the thalamus of the anesthetized rat. The results suggest that the N-type voltage-sensitive calcium channel is the primary VSCC involved in the electrically stimulated release of DA in the striatum, whereas stimulated release of NE in the thalamus was only partially dependent on N-type VSCC. In addition, DA release appears to be more sensitive to VSCC antagonism than does NE release with the in vivo application used in this study.
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Affiliation(s)
- K Mitchell
- Department of Chemistry, University of Kansas, Lawrence 66045
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31
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Kuczenski R, Segal DS. Regional norepinephrine response to amphetamine using dialysis: comparison with caudate dopamine. Synapse 1992; 11:164-9. [PMID: 1626314 DOI: 10.1002/syn.890110210] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The response of extracellular norepinephrine to the acute administration of amphetamine was assessed, using dialysis, in prefrontal cortex and hippocampus in awake, behaving rats. Norepinephrine exhibited a pronounced and rapid dose- and time-dependent increase in response to 0.5 and 2.5 mg/kg amphetamine, which corresponded closely to the time course of the behavioral profile. These results are consistent in with a possible role for norepinephrine in the behavioral response to amphetamine.
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Affiliation(s)
- R Kuczenski
- Department of Psychiatry, University of California, San Diego, La Jolla 92093-0603
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Cenci MA, Kalén P, Mandel RJ, Björklund A. Regional differences in the regulation of dopamine and noradrenaline release in medial frontal cortex, nucleus accumbens and caudate-putamen: a microdialysis study in the rat. Brain Res 1992; 581:217-28. [PMID: 1393530 DOI: 10.1016/0006-8993(92)90711-h] [Citation(s) in RCA: 166] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Dopamine (DA) and noradrenaline (NA) extracellular levels have been measured by microdialysis in the medial frontal cortex (MFC), nucleus accumbens (NAc) and caudate-putamen (CP) under baseline conditions in awake and halothane-anaesthetized rats, and after application of three types of stimuli which are likely to activate the brainstem catecholaminergic systems: mild stressors (handling and tail pinch), rewarded behavior (eating palatable food without prior food deprivation) and electrical stimulation of the lateral habenular nucleus. Changes were studied with and without uptake blockade (10 microM nomifensine in the perfusion fluid). The influence of calcium concentration (1.2 or 2.3 mM in the perfusion fluid) on DA and NA overflow was tested in some cases. Handling and tail pinch stimulated both DA and NA overflow in MFC, and enhanced NA overflow in NAc. By contrast, these mildly stressful stimuli had only marginal effects on DA overflow in NAc and no effects on either DA or NA overflow in CP. Eating behavior was accompanied by increased DA and NA overflow in MFC but had no effect in NAc. These regional differences were similar also when the manipulations were applied under uptake blockade, which indicates that the more pronounced changes seen in MFC did not simply reflect a more sparse innervation (i.e. lower density of uptake sites) in the MFC compared to the more densely innervated NAc and CP areas. Stimulation of the lateral habenula induced a 2-3-fold increase in NA overflow in both MFC, NAc and CP but had no consistent effect on DA overflow in any region. The effect on NA release was abolished by a transection of the ipsilateral fasciculus retroflexus (which carries the efferent output of the lateral habenula). The results show that the forebrain DA and NA projections to cortical and striatal targets are differentially regulated during ongoing behavior, that the mesocortical and mesostriatal DA systems respond quite differently to stressful and rewarding stimuli; and that the NA projection to MFC (like the dopaminergic one) is more responsive to stressful and rewarding stimuli than the ones innervating the striatum (NAc and CP). The results support the view that environmental stimuli evoking emotional arousal (whether aversive or non-aversive) are accompanied by increased DA and NA release above all in the MFC and only to a minor extent in limbic and striatal areas.
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Affiliation(s)
- M A Cenci
- Department of Medical Cell Research, University of Lund, Sweden
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Britton KT, Segal DS, Kuczenski R, Hauger R. Dissociation between in vivo hippocampal norepinephrine response and behavioral/neuroendocrine responses to noise stress in rats. Brain Res 1992; 574:125-30. [PMID: 1638389 DOI: 10.1016/0006-8993(92)90808-m] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The behavioral and extracellular hippocampal norepinephrine responses to audiogenic stress were concomitantly characterized in freely moving rats using in vivo microdialysis. Noise stimulation produced a rapid, but short-lived increase in norepinephrine release from the hippocampus during the first 20 min of noise presentation that declined to baseline levels for the duration of the noise stimulation and following noise offset. In contrast, the behavioral response persisted throughout the duration of the noise stimulation. In a separate group of similarly treated animals, neuroendocrine indices of stress were monitored during exposure to noise. Consistent with the behavioral response, corticosterone and adrenocorticotropic hormone remained elevated for the duration of noise presentation. These findings support a dissociation between the hippocampal norepinephrine response and the behavioral and neuroendocrine response patterns and suggest that other systems may be involved in the regulation of behavioral responsiveness to aversive stimuli.
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Affiliation(s)
- K T Britton
- Department of Psychiatry, San Diego VAMC, La Jolla, CA 92161
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Erdtsieck-Ernste EB, Feenstra MG, Botterblom MH, De Barrios J, Boer GJ. Changes in adrenoceptors and monoamine metabolism in neonatal and adult rat brain after postnatal exposure to the antihypertensive labetalol. Br J Pharmacol 1992; 105:37-44. [PMID: 1596689 PMCID: PMC1908619 DOI: 10.1111/j.1476-5381.1992.tb14207.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
1. The purpose of the present study was to investigate the acute (single injection), direct (chronic treatment) and the long-lasting effects after exposure to the alpha 1/beta-adrenoceptor antagonist labetalol during rat brain development on adrenoceptors and monoamine metabolism. 2. In 10-day-old rat pups, subcutaneously administered labetalol (10 mg kg-1) passed the blood-brain barrier, reaching a level of 2.1 micrograms g-1 tissue in the brain 90 min after injection. 3. Chronic labetalol treatment (10 mg kg-1, s.c., twice daily) during the first 10 days of life significantly increased alpha 1-adrenoceptor binding in the hypothalamus (+39%), but not in the occipital cortex. 4. This chronic postnatal labetalol treatment did not result in long-lasting changes in alpha 1- and beta-receptors measured on day 60. 5. A single labetalol injection (10 mg kg-1, s.c.) on postnatal day 10 significantly increased noradrenaline (NA) metabolism in all brain regions tested (+25 to 105%), but had no effects on 5-hydroxytryptamine (5-HT) or dopamine metabolism. 6. Chronic labetalol treatment between postnatal (PN) days 1 and 10 also increased NA metabolism on PN 10 (3-methoxy-4-hydroxyphenylglycol (MHPG)/NA, +20 to 100%), suggesting that tolerance to the acute effect of labetalol did not occur. A slight increase in 5-HT metabolism (20%) was induced by the chronic labetalol treatment in the hippocampus and meso-limbic system. 7. In general, long-lasting effects on NA metabolism could not be detected on day 60 more than one month after the treatment. However, 5-HT metabolism was significantly increased in all four brain regions measured (+20 to 70%). 8. We conclude that chronic labetalol exposure during early postnatal rat brain development does not cause long-lasting changes in beta-receptor number or NA metabolism, but appears to be critical for the rate of 5-HT metabolism in later life.
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