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Goncharuk VD, Buijs RM, Jhamandas JH, Swaab DF. The hypothalamic neuropeptide FF network is impaired in hypertensive patients. Brain Behav 2014; 4:453-67. [PMID: 25161813 PMCID: PMC4075637 DOI: 10.1002/brb3.229] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Revised: 03/02/2014] [Accepted: 03/13/2014] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND The human hypothalamus contains the neuropeptide FF (NPFF) neurochemical network. Animal experiments demonstrated that NPFF is implicated in the central cardiovascular regulation. We therefore studied expression of this peptide in the hypothalamus of individuals who suffered from essential hypertension (n = 8) and died suddenly due to acute myocardial infarction (AMI), and compared to that of healthy individuals (controls) (n = 6) who died abruptly due to mechanical trauma of the chest. METHODS The frozen right part of the hypothalamus was cut coronally into serial sections of 20 μm thickness, and each tenth section was stained immunohistochemically using antibody against NPFF. The central section through each hypothalamic nucleus was characterized by the highest intensity of NPFF immunostaining and thus was chosen for quantitative densitometry. RESULTS In hypertensive patients, the area occupied by NPFF immunostained neuronal elements in the central sections through the suprachiasmatic nucleus (SCh), paraventricular hypothalamic nucleus (Pa), bed nucleus of the stria terminalis (BST), perinuclear zone (PNZ) of the supraoptic nucleus (SON), dorso- (DMH), ventromedial (VMH) nuclei, and perifornical nucleus (PeF) was dramatically decreased compared to controls, ranging about six times less in the VMH to 15 times less in the central part of the BST (BSTC). The NPFF innervation of both nonstained neuronal profiles and microvasculature was extremely poor in hypertensive patients compared to control. CONCLUSIONS The decreased NPFF expression in the hypothalamus of hypertensive patients might be a cause of impairment of its interaction with other neurochemical systems, and thereby might be involved in the pathogenesis of the disease.
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Affiliation(s)
- Valeri D Goncharuk
- Netherlands Institute for Neuroscience Amsterdam ZO, 1105 BA, The Netherlands ; Russian Cardiology Research Center Moscow, 121552, Russia ; Division of Neurology, Department of Medicine, University of Alberta Edmonton, AB, T6G 2S2, Canada
| | - Ruud M Buijs
- Instituto de Investigaciones Biomedicas, Universidad Nacional Autonoma de Mexico Mexico City, 04510, Mexico
| | - Jack H Jhamandas
- Division of Neurology, Department of Medicine, University of Alberta Edmonton, AB, T6G 2S2, Canada
| | - Dick F Swaab
- Netherlands Institute for Neuroscience Amsterdam ZO, 1105 BA, The Netherlands
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2
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Modification of the cardiovascular response of posterior hypothalamic adenosine A2A receptor stimulation by adenylate cyclase and KATP channel blockade in anesthetized rats. Auton Neurosci 2009; 146:70-5. [DOI: 10.1016/j.autneu.2008.11.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2008] [Revised: 11/19/2008] [Accepted: 11/25/2008] [Indexed: 11/18/2022]
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3
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Involvement of NO and KATP Channel in Adenosine A2B Receptors Induced Cardiovascular Regulation in the Posterior Hypothalamus of Rats. J Cardiovasc Pharmacol 2009; 53:167-72. [DOI: 10.1097/fjc.0b013e318198ca6b] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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4
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Kang MJ, Koh HC. Involvement of guanylate cyclase in the cardiovascular response induced by adenosine A2B receptor stimulation in the posterior hypothalamus of the anesthetized rats. Auton Neurosci 2007; 134:55-60. [PMID: 17363336 DOI: 10.1016/j.autneu.2007.02.004] [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] [Received: 07/11/2006] [Revised: 01/31/2007] [Accepted: 02/11/2007] [Indexed: 11/29/2022]
Abstract
Cardiovascular inhibitory effects induced by the posterior hypothalamic adenosine A(2) receptors were suggested by our previous reports. In this experiment, we examined the influence of the posterior hypothalamic adenosine A(2B) receptors on central cardiovascular regulation of blood pressure (BP) and heart rate (HR). Posterior hypothalamic injection of drugs was performed in anesthetized, artificially ventilated male Sprague-Dawley rats. Injection of 5'-(N-cyclopropyl)-carboxamidoadenosine (CPCA; 2 nmol), an adenosine A(2) receptor agonist, showed the decrease of arterial blood pressure and heart rate, and the alloxazine, an adenosine A(2B) receptor antagonist, partially blocked the depressor and bradycardiac effects of CPCA (2 nmol). To examine the role of adenosine A(2B) receptors among the adenosine A(2) subtypes, we applied the 5'-N-Ethylcarboxamidoadenosine (NECA), an adenosine A(2B) receptor agonist, to the posterior hypothalamus. Injection of NECA (1, 4 and 8 nmol) produced a dose-dependent decrease of arterial blood pressure and HR. Pretreatment with alloxazine (5 nmol) partially blocked the depressor and bradycardiac effects of NECA (4 nmol). Also, pretreatment with LY-83,583 (5 nmol), a soluble guanylate cyclase inhibitor, attenuated the depressor and bradycardiac effects of NECA (4 nmol). However, pretreatment with MDL-12,330 (10 nmol), an adenylate cyclase inhibitor, did not affect these effects of NECA (4 nmol). These results suggest that adenosine A(2B) receptor in the posterior hypothalamus plays an inhibitory role in central cardiovascular regulation, and that guanylate cyclase mediates the depressor and bradycardiac actions of adenosine A(2B) receptors.
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Affiliation(s)
- Min Jeong Kang
- Department of Pharmacology, College of Medicine, Hanyang University, 17 Haengdang-Dong, Sungdong-Ku, Seoul 133-791, Republic of Korea
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Kaehler ST, Salchner P, Singewald N, Philippu A. Differential amino acid transmission in the locus coeruleus of Wistar Kyoto and spontaneously hypertensive rats. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2004; 370:381-7. [PMID: 15526108 DOI: 10.1007/s00210-004-0987-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2004] [Accepted: 09/07/2004] [Indexed: 11/25/2022]
Abstract
In addition to differences in their blood pressure, Wistar Kyoto (WKY) and spontaneously hypertensive rats (SHR) are known to differ in their emotional behaviour. The neurochemistry underlying these differences is not well understood. In the present study the release rates of the two main regulatory amino acids in the locus coeruleus, glutamate and gamma-aminobutyric acid (GABA), were monitored in WKY rats and SHR to investigate whether basal and/or challenged neurotransmission differs between these strains. The strains differed in their basal blood pressure (WKY 102+/-2 mmHg, SHR 140+/-4 mmHg), as well as in their emotional behaviour, since WKY rats displayed enhanced anxiety-related behaviour in the open field test (time in centre: WKY 197+/-40 s/30 min, SHR 741+/-93 s/30 min). Basal glutamate and GABA release rates did not differ between WKY rats and SHR. A rise in blood pressure induced by intravenous infusion of noradrenaline for 10 min enhanced GABA release in WKY rats by 60%, while no effect was observed in SHR. Glutamate release did not respond to experimental hypertension in both strains. Intravenous infusion of sodium nitroprusside led to a fall in blood pressure, which was less pronounced and was of shorter duration in WKY rats than in SHR. The depressor response had no effect on amino acid release in the locus coeruleus of both strains. Mild stress induced by noise or tail pinch led to slight rises in arterial blood pressure (10 mmHg and 20 mmHg respectively), which were similar in WKY rats and SHR. Tail pinch enhanced the release rates of glutamate and GABA in the locus coeruleus of WKY rats and SHR; however, no strain differences were noted. Noise stress did not significantly influence amino acid release. These findings demonstrate that SHR and WKY rats differ in GABAergic neurotransmission, which is revealed in response to specific cardiovascular challenges, but not to mild stressors. The observed lack of GABA response to blood pressure elevation in SHR may reflect a disturbed mechanism counteracting high blood pressure, possibly contributing to hypertension in this strain.
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Affiliation(s)
- S T Kaehler
- Department of Pharmacology and Toxicology, University of Innsbruck, Peter-Mayr-Strasse 1, 6020 Innsbruck, Austria.
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6
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Kang MJ, Park MS, Shin IC, Koh HC. Modification of cardiovascular response of posterior hypothalamic adenosine A(2) receptor stimulation by adenylate cylase, guanylate cyclase and by K(ATP) channel blockade in anesthetized rats. Neurosci Lett 2003; 344:57-61. [PMID: 12781921 DOI: 10.1016/s0304-3940(03)00402-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Cardiovascular inhibitory effects induced by posterior hypothalamic adenosine A(2) receptors and their modulation by nitric oxide were suggested by our previous report. In this experiment, we examined the modulation of cardiovascular effects of adenosine A(2) receptor stimulation by adenylate cyclase, guanylate cyclase and ATP-sensitive K(+) channel in the posterior hypothalamus. Posterior hypothalamic injection of drugs was performed in anesthetized, artificially ventilated male Sprague-Dawley rats. Injection of adenosine A(2) receptor agonist 5'-(N-cyclopropyl)-carboxamidoadenosine (CPCA; 1, 2 and 5 nmol) produced a dose-dependent decrease of blood pressure and heart rate. Pretreatment with adenosine A(2) receptor antagonist 3,7-dimethyl-1-propargylxanthine (10 nmol) blocked the depressor and bradycardiac effects of CPCA (5 nmol). Pretreatments with adenylate cyclase inhibitor MDL-12330 (10 nmol) and guanylate cyclase inhibitor LY-83583 (5 nmol) attenuated the depressor and bradycardiac effects of CPCA (5 nmol). In addition, pretreatment with ATP-sensitive K(+) channel blocker glipizide (20 nmol) attenuated the depressor and bradycardiac responses of CPCA (5 nmol). These results suggest that posterior hypothalamic adenosine A(2) receptors play an inhibitory role in the central cardiovascular regulation and that both adenylate cyclase and guanylate cyclase mediate the depressor and bradycardiac actions of adenosine A(2) receptors. Also, ATP-sensitive K(+) channel mediates the posterior hypothalamic cardiovascular regulations of adenosine A(2) receptors.
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Affiliation(s)
- Min Jeong Kang
- Department of Pharmacology, College of Medicine, Hanyang University, 17 Haengdang-Dong, Sungdong-Ku, Seoul 133-791, South Korea
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Wotjak CT, Ludwig M, Ebner K, Russell JA, Singewald N, Landgraf R, Engelmann M. Vasopressin from hypothalamic magnocellular neurons has opposite actions at the adenohypophysis and in the supraoptic nucleus on ACTH secretion. Eur J Neurosci 2002; 16:477-85. [PMID: 12193191 DOI: 10.1046/j.1460-9568.2002.02101.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Magnocellular vasopressinergic and oxytocinergic neurons of the hypothalamic supraoptic (SON) and paraventricular nuclei comprise the hypothalamic-neurohypophysial system, which is crucially involved in the regulation of body fluid and electrolyte homeostasis. However, still controversial is to what extent the same system influences the secretion of adrenocorticotropic hormone (ACTH) from the adenohypophysis. Therefore, we selectively stimulated magnocellular neurons of the SON of conscious male Wistar rats via retrodialysis. As expected, dialysis of the SON with hypertonic medium increased both the release of vasopressin within the SON and the secretion of vasopressin and oxytocin into the systemic blood circulation. This activation of the hypothalamic-neurohypophysial system was accompanied by a fivefold increase in plasma ACTH concentration. This effect was observed only if the tip of the microdialysis probe was within the SON. Intravenous infusion of the vasopressin V1 receptor antagonist d(CH2)5Tyr(Me)AVP significantly attenuated the effects of local osmotic stimulation of the SON on ACTH secretion. In contrast, administration of the same antagonist directly into the SON significantly enhanced the osmotically stimulated secretion of ACTH and corticosterone, primarily by delaying the restoration of the hormone secretion to prestimulation levels. We conclude from these findings that vasopressin from the hypothalamic-neurohypophysial system participates in the regulation of the hormonal stress response in a counterbalanced manner at the level of the SON and the adenohypophysis.
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Affiliation(s)
- Carsten T Wotjak
- Max-Planck-Institut für Psychiatrie, Kraepelinstr. 2, D-80804 München, Germany
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8
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Song MS, Shin KA, Kang JS, Lee CH, Shin IC, Lee SJ, Koh HC. The involvement of nitric oxide on the adenosine A(2) receptor-induced cardiovascular inhibitory responses in the posterior hypothalamus of rats. Neurosci Lett 2002; 326:41-5. [PMID: 12052534 DOI: 10.1016/s0304-3940(02)00290-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
This study was performed to investigate the putative relationship between nitric oxide (NO) and adenosine A(2) receptors on central cardiovascular regulation in the posterior hypothalamus of rats. Posterior hypothalamic injection of drugs was performed in anesthetized, artificially ventilated male Sprague-Dawley rats. Injection of adenosine A(2) receptor agonist 5'-(N-cyclopropyl)-carboxamidoadenosine (CPCA; 1, 2 and 5 nmol) produced a dose-dependent decrease of blood pressure and heart rate. Pretreatment with adenosine A(2) receptor antagonist 3,7-dimethyl-1-propargylxanthine (10 nmol) blocked the depressor and bradycardiac effects of CPCA (5 nmol). Pretreatment with soluble guanylate cyclase inhibitor LY-83,583 (5 nmol) attenuated the depressor and bradycardiac effects of CPCA (5 nmol). In addition, pretreatment with NO synthase inhibitor N(G)-nitro-L-arginine methyl ester (40 nmol) attenuated the depressor and bradycardiac responses of CPCA (5 nmol). These results suggest that adenosine A(2) receptor in the posterior hypothalamus plays an inhibitory role in central cardiovascular regulation and that NO participates in the inhibitory response induced by adenosine A(2) receptor stimulation in the posterior hypothalamus.
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Affiliation(s)
- Man Sung Song
- Department of Pharmacology, College of Medicine, Hanyang University, 17 Haengdang-Dong, Sungdong-Ku, Seoul 133-791, South Korea
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9
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Engelmann M, Ludwig M, Singewald N, Ebner K, Sabatier N, Lubec G, Landgraf R, Wotjak CT. Taurine selectively modulates the secretory activity of vasopressin neurons in conscious rats. Eur J Neurosci 2001; 14:1047-55. [PMID: 11683896 DOI: 10.1046/j.0953-816x.2001.01729.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Previous experiments have shown that a 10-min forced swimming session triggers the release of vasopressin from somata and dendrites, but not axon terminals, of neurons of the hypothalamic-neurohypophysial system. To further investigate regulatory mechanisms underlying this dissociated release, we forced male Wistar rats to swim in warm (20 degrees C) water and monitored release of the potentially inhibitory amino acids gamma amino butyric acid (GABA) and taurine into the hypothalamic supraoptic nucleus using microdialysis. Forced swimming caused a significant increase in the release of taurine (up to 350%; P < 0.05 vs. prestress release), but not GABA. To reveal the physiological significance of centrally released taurine, the specific taurine antagonist 6-aminomethyl-3-methyl-4H-1,2,4-benzothiadiazine-1,1-dioxide was administered into the supraoptic nucleus via retrodialysis. Administration of this antagonist caused a significant increase in the release of vasopressin within the supraoptic nucleus and into the blood both under basal conditions and during stress (up to 800%; P < 0.05 vs. basal values), without affecting hypothalamic or plasma oxytocin. Local administration of the GABA(A) receptor antagonist bicuculline, in contrast, failed to influence vasopressin secretion at either time point. In a separate series of in vivo electrophysiological experiments, administration of the same dosage of the taurine antagonist into the supraoptic nucleus via microdialysis resulted in an increased electrical activity of identified vasopressinergic, but not oxytocinergic, neurons. Taken together our data demonstrate that taurine is released within the supraoptic nucleus during physical/emotional stress. Furthermore, at the level of the supraoptic nucleus, taurine inhibits not only the electrical activity of vasopressin neurons but also acts as an inhibitor of both central and peripheral vasopressin secretion during different physiological states.
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Affiliation(s)
- M Engelmann
- Institut für Medizinische Neurobiologie, Otto-von-Guericke-Universität Magdeburg, Leipziger Str. 44. D-39120 Magdeburg, Germany.
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10
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Lee HH, Koh HC, Chae SL, Kang JS, Lee CH, Paik DJ, Shin IC. Modification of cardiovascular responses to adenosine A1 receptor stimulation in the posterior hypothalamus of anaesthetized rats by cAMP and by GABA(B) receptor blockade. JOURNAL OF AUTONOMIC PHARMACOLOGY 2001; 21:249-54. [PMID: 12123470 DOI: 10.1046/j.1365-2680.2001.00236.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
1 Injection of N(6)-cyclohexyladenosine (CHA; 1, 5 and 10 nmol), an adenosine A1 receptor agonist, into the posterior hypothalamus of rats produced a dose-dependent decrease in blood pressure (BP) and heart rate (HR). 2 Pretreatment with 8-cyclopentyl-1,3-dimethylxanthine (CPDX; 50 nmol), an adenosine A1 receptor antagonist, blocked the depressor and bradycardic effects of CHA (10 nmol). 3 Pretreatment with 8-bromo-cyclic adenosine monophosphate (AMP) (10 nmol), a cAMP analogue, attenuated the depressor and bradycardic effect of CHA (10 nmol); 8-bromo-cyclic guanosine monophosphate (GMP) (10 nmol), a cGMP analogue, did not modify those effects of CHA. 4 In addition, pretreatment with 5-aminovaleric acid (25 nmol), a gamma-aminobutyric acid (GABA)(B) receptor antagonist, attenuated the depressor and bradycardic effects of CHA (10 nmol). 5 These results suggest that adenosine A1 receptors in the posterior hypothalamus have an inhibitory role in the central cardiovascular regulation and that these vasodepressive and bradycardic actions are modified by raised cAMP and by GABA(B) receptor inhibition.
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Affiliation(s)
- H H Lee
- Departments of Pharmacology, College of Medicine, Hanyang University, 17 Haengdang-Dong, Sungdong-Gu, Seoul 133-791, South Korea
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Keck ME, Sillaber I, Ebner K, Welt T, Toschi N, Kaehler ST, Singewald N, Philippu A, Elbel GK, Wotjak CT, Holsboer F, Landgraf R, Engelmann M. Acute transcranial magnetic stimulation of frontal brain regions selectively modulates the release of vasopressin, biogenic amines and amino acids in the rat brain. Eur J Neurosci 2000; 12:3713-20. [PMID: 11029641 DOI: 10.1046/j.1460-9568.2000.00243.x] [Citation(s) in RCA: 127] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Using intracerebral microdialysis in urethane-anaesthetized adult male Wistar rats, we monitored the effects of acute repetitive transcranial magnetic stimulation (rTMS; 20 trains of 20 Hz, 2.5 s) on the intrahypothalamic release of arginine vasopressin (AVP) and selected amino acids (glutamate, glutamine, aspartate, serine, arginine, taurine, gamma-aminobutyric acid) and the intrahippocampal release of monoamines (dopamine, noradrenaline, serotonin) and their metabolites (homovanillic acid, 3,4-dihydroxyphenylacetic acid, 5-hydroxyindoleacetic acid). The stimulation parameters were adjusted according to the results of accurate computer reconstructions of the current density distributions induced by rTMS in the rat and human brains, ensuring similar stimulation patterns in both cases. There was a continuous reduction in AVP release of up to 50% within the hypothalamic paraventricular nucleus in response to rTMS. In contrast, the release of taurine, aspartate and serine was selectively stimulated within this nucleus by rTMS. Furthermore, in the dorsal hippocampus the extracellular concentration of dopamine was elevated in response to rTMS. Taken together, these data provide the first in vivo evidence that acute rTMS of frontal brain regions has a differentiated modulatory effect on selected neurotransmitter/neuromodulator systems in distinct brain areas.
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Affiliation(s)
- M E Keck
- Max Planck Institute of Psychiatry, Munich, Germany.
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12
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Singewald N, Ebner K, Landgraf R, Wotjak CT, Engelmann M. Vasopressin selectively modulates the release of taurine within the septum of the rat brain. Neurosci Lett 1999; 277:68-70. [PMID: 10643900 DOI: 10.1016/s0304-3940(99)00841-1] [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: 11/28/2022]
Abstract
Previous experiments have shown that arginine vasopressin (AVP) released within the septal brain area of adult male rats in response to defined stressor exposure is involved in emotionality-related behavior. We report here that a 10-min forced swimming session stimulated the release of glutamate, aspartate, arginine, gamma-aminobutyric acid (GABA) and taurine but not alanine and serine in the medio-lateral part of this brain structure. Local administration of the AVP V1 receptor antagonist d(CH2)5Tyr(Me)AVP by inverse microdialysis caused a significant increase in the concentration of taurine in microdialysates under resting conditions that was further potentiated during forced swimming. In contrast, the release of alanine, arginine, GABA and serine was unaffected by antagonist treatment. Taken together with previous data, our results suggest that the effects of intraseptally released AVP on stress-coping strategies might be mediated at least in part via its influence on the local release of taurine.
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Affiliation(s)
- N Singewald
- Universität Innsbruck, Institut für Pharmakologie and Toxikologie, Austria
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13
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Liu H, Mihailoff GA. Hypothalamopontine projections in the rat: anterograde axonal transport studies utilizing light and electron microscopy. THE ANATOMICAL RECORD 1999; 255:428-51. [PMID: 10409816 DOI: 10.1002/(sici)1097-0185(19990801)255:4<428::aid-ar9>3.0.co;2-s] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Projections to the basilar pontine nuclei (BPN) from a variety of hypothalamic nuclei were traced in the rat utilizing the anterograde transport of biotinylated dextran amine. Light microscopy revealed that the lateral hypothalamic area (LH), the posterior hypothalamic area (PH), and the medial and lateral mammillary nuclei (MMN and LMN) are the four major hypothalamic nuclei that give rise to labeled fibers and terminals reaching the rostral medial and dorsomedial BPN subdivisions. Hypothalamopontine fibers extended caudally through the pontine tegmentum dorsal to the nucleus reticularis tegmenti pontis and then coursed ventrally from the main descending bundle toward the ipsilateral basilar pontine gray. Some hypothalamopontine fibers crossed the midline in the tegmental area just dorsal to the pontine gray to terminate in the contralateral BPN. Electron microscopy revealed that the ultrastructural features of synaptic boutons formed by axons arising in the LH, PH, MMN, and LMN are similar to one another. All labeled hypothalamopontine axon terminals contained round synaptic vesicles and formed asymmetric synaptic junctions with dendritic shafts as well as dendritic appendages, and occasionally with neuronal somata. Some labeled boutons formed the central axon terminal in a glomerular synaptic complex. In summary, the present findings indicate that the hypothalamus projects predominantly to the rostral medial and dorsomedial portions of the BPN which, in turn, provide input to the paraflocculus and vermis of the cerebellum. Since the hypothalamic projection zones in the BPN also receive cerebral cortical input, including limbic-related cortex, the hypothalamopontine system might serve to integrate autonomic or limbic-related functions with movement or somatic motor-related activity. Alternatively, since the cerebellum also receives direct input from the hypothalamus, the BPN may function to provide additional somatic and visceral inputs that are used by the cerebellum to perform the integrative function.
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Affiliation(s)
- H Liu
- Department of Anatomy, University of Mississippi Medical Center, Jackson, Mississippi 39216-4505, USA
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14
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Malone DT, Taylor DA. Modulation of delta9-tetrahydrocannabinol-induced hypothermia by fluoxetine in the rat. Br J Pharmacol 1998; 124:1419-24. [PMID: 9723953 PMCID: PMC1565537 DOI: 10.1038/sj.bjp.0701980] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
1. It has been suggested that the dose of delta9-tetrahydrocannabinol (delta9-THC) that induces hypothermia in the rat increases the release of brain 5-hydroxytryptamine (5-HT). In light of this, we investigated the hypothermia produced by delta4-THC, and the effect the selective serotonin reuptake inhibitor fluoxetine has on this response. 2. A significant dose-dependent decrease in body temperature occurred after i.v. administration of 0.5 to 5 mg kg(-1) delta9-THC; maximum decreases being 0.8+/-0.2 degrees C to 2.9+/-0.3 degrees C. This hypothermic response was attenuated by the cannabinoid CB1 receptor antagonist SR 141716. 3. Fluoxetine (10 mg kg(-1) i.p.) alone caused a decrease in body temperature of 0.6+/-0.1 degrees C (n=32, P < 0.05) after 40 min. However, pretreatment with fluoxetine (10 mg kg(-1) i.p.) 40 min before delta9-THC significantly reduced the delta9-THC-induced hypothermia (n=7-8, P < 0.05). Contrary to this antagonist-like effect, fluoxetine administered 40 min after delta9-THC significantly potentiated the delta9-THC-induced hypothermia, producing a maximum decrease of 3.2+/-0.3 degrees C. 4. It is suggested that the effect of fluoxetine on the delta9-THC-induced hypothermic response is dependent on the time of its administration relative to that of delta9-THC. Pretreatment with fluoxetine increases extracellular 5-HT due to reuptake inhibition. Increased extracellular 5-HT can activate autoreceptors which may decrease serotonergic activity, thereby reducing the delta9-THC-induced hypothermia. Conversely, when fluoxetine is administered after delta9-THC, the reuptake block is thought to potentiate the already activated serotonergic system, hence potentiating the delta9-THC-induced hypothermia.
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Affiliation(s)
- D T Malone
- Department of Pharmaceutical Biology and Pharmacology, Victorian College of Pharmacy (Monash University), Parkville, Australia
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15
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Singewald N, Philippu A. Involvement of biogenic amines and amino acids in the central regulation of cardiovascular homeostasis. Trends Pharmacol Sci 1996. [DOI: 10.1016/s0165-6147(96)80009-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Singewald N, Zhou GY, Schneider C. Release of excitatory and inhibitory amino acids from the locus coeruleus of conscious rats by cardiovascular stimuli and various forms of acute stress. Brain Res 1995; 704:42-50. [PMID: 8750960 DOI: 10.1016/0006-8993(95)01102-1] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The release of amino acids in the locus coeruleus (LC) of conscious, freely moving rats was studied in time periods of 3 min by use of push-pull superfusion under basal conditions and during application of various experimental stimuli known to influence the activity of the LC-noradrenergic system. Tail pinch for 3 min led immediately to a pronounced tetrodotoxin-sensitive increase in the release rates of the excitatory amino acids (EAA) glutamate (Glu) and aspartate (Asp) and to moderate increases in GABA and taurine (Tau) outflow. Immobilization stress for 9 min elevated the release of the EAA Glu and Asp, as well as that of the inhibitory amino acid GABA to a similar extent. A fall of blood pressure (BP) by nitroprusside or haemorrhage slightly enhanced the release rates of Glu and Asp. Noradrenaline-induced rise in BP, as well as hypervolaemia increased the release rate of GABA, but did not influence the release rates of Glu, Asp, Tau and arginine (Arg). The results provide direct evidence that the amino acid release pattern in the LC of conscious rats differs in response to various stimuli, according to the modality of the stimulus. A functional significance of excitatory and inhibitory amino acids in the regulation of LC activity during stress and haemodynamic changes is suggested.
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Affiliation(s)
- N Singewald
- Department of Pharmacology and Toxicology, University of Innsbruck, Austria.
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Dickinson TK, Connor JR. Cellular distribution of iron, transferrin, and ferritin in the hypotransferrinemic (Hp) mouse brain. J Comp Neurol 1995; 355:67-80. [PMID: 7636015 DOI: 10.1002/cne.903550109] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Hypotransferrinemic (Hp) mice have a point mutation or small deletion in the transferrin (Tf) gene, resulting in defective splicing of precursor Tf mRNA. Hp animals produce < 1% of normal Tf levels and require supplemental serum or purified Tf for survival. Because of the lack of endogenous brain Tf, we examined regional and cellular distributions of iron and iron regulatory proteins (Tf and ferritin) in selected brain regions of Hp mice. The regional distribution of iron, Tf, and ferritin in Hp brain was similar to normal except for the pattern of iron staining in hippocampus. The cellular distribution of iron, ferritin, and Tf was similar between Hp and normal animals. The predominant cell type staining for Tf and iron was oligodendrocytes. Qualitative observations suggest that the number of cells staining for iron was similar between Hp and normal mice, whereas the number of Hp Tf-positive cells was reduced. Ferritin immunostaining was similar in both cases. However, ferritin-positive cells were predominantly astrocytes, an observation unique to mice among species studied previously. Western blot analysis revealed that Tf present in Hp brain was of exogenous origin (from supplemental injections). Presumably, Tf transports the iron found in Hp oligodendrocytes. These data demonstrate that, despite reduced endogenous Hp brain Tf, iron and plasma Tf migrate or are transported to the appropriate cells (oligodendrocytes), bringing into question the role of endogenous brain Tf in extracellular iron transport.
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Affiliation(s)
- T K Dickinson
- George M. Leader Family Laboratory For Alzheimer's Disease Research, Department of Neuroscience and Anatomy, Pennsylvania State University, College of Medicine, M.S. Hershey Medical Center, Hershey 17033, USA
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Jastrzebski Z, Czyzewska-Szafran H, Goźlińska B, Remiszewska M, Mazurek AP. Clonidine hypotension in spontaneously hypertensive rats (SHR) depends on the functional state of GABAergic and glutamatergic systems. Neurosci Lett 1995; 184:94-6. [PMID: 7724054 DOI: 10.1016/0304-3940(94)11177-k] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The effect of gamma-aminobutyric acid (GABA)A receptors and of the N-methyl-D-aspartate (NMDA) subtype of glutamate receptor blockade on clonidine hypotension was studied. The experiments were performed on spontaneously hypertensive (SHR) and normotensive Wistar-Kyoto (WKY) rats. We found that the blockade of GABAA receptors line significantly (P < 0.01) reduced hypotensive responses to clonidine. Similarly, the NMDA receptor antagonist dizocilpine (MK-801) completely abolished the blood pressure lowering effect of clonidine. Our findings support the conclusion that clonidine hypotension is closely related to the functional state of both inhibitory GABAergic and excitatory glutamatergic systems.
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Affiliation(s)
- Z Jastrzebski
- Department of Pharmacology, Drug Institute, Warsaw, Poland
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Singewald N, Schneider C, Philippu A. Effects of neuroactive compounds, noxious and cardiovascular stimuli on the release of amino acids in the rat locus coeruleus. Neurosci Lett 1994; 180:55-8. [PMID: 7877762 DOI: 10.1016/0304-3940(94)90912-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The release of excitatory amino acids (glutamate, aspartate), inhibitory amino acids (GABA, taurine) and arginine was determined in the locus coeruleus (LC) of anaesthetized rats. The neuronal origin of stimulated amino acid release was verified by superfusion with neuroactive compounds. Electrical stimulation of the sciatic nerve, as well as mechanical footshock, enhanced LC release rates of glutamate and aspartate without influencing those of taurine and arginine. GABA release rate was increased slightly after some delay. Excitatory amino acid release was not influenced by changes in blood pressure. The results provide direct neurochemical evidence that noxious stimuli activate LC neurons via the glutamate and aspartate input into this nucleus.
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Affiliation(s)
- N Singewald
- Department of Pharmacology and Toxicology, University of Innsbruck, Austria
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Sim MK, Radhakrishnan R. Effect of pentobarbital and chlordiazepoxide on the central pressor action of angiotensins in normo- and hypertensive rats. Eur J Pharmacol 1994; 253:171-4. [PMID: 8013543 DOI: 10.1016/0014-2999(94)90773-0] [Citation(s) in RCA: 4] [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
Pentobarbital and chlordiazepoxide administered intracerebroventricularly (i.c.v.) attenuated dose dependently the pressor action of i.c.v. angiotensin II and angiotensin III in the conscious spontaneously hypertensive rat (SHR) and the normotensive control Wistar Kyoto rat (WKY). Attenuation of the pressor action by the two drugs was more marked in the WKY than in the SHR. Based on the fact that both drugs act via the gamma-aminobutyric acid (GABA) receptors, the data support the suggestions (i) that a central GABAergic system regulates blood pressure, (ii) that there is probable dysfunction of the GABA receptors in SHR.
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Affiliation(s)
- M K Sim
- Department of Pharmacology, Faculty of Medicine, National University of Singapore
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Singewald N, Guo LJ, Philippu A. Taurine release in the hypothalamus is altered by blood pressure changes and neuroactive drugs. Eur J Pharmacol 1993; 240:21-7. [PMID: 8104813 DOI: 10.1016/0014-2999(93)90540-x] [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: 01/28/2023]
Abstract
The release of endogenous taurine was determined in the posterior hypothalamus of the conscious, freely moving rat by using the push-pull superfusion technique. At the start of superfusion, the outflow of endogenous taurine declined rapidly with a half-time of 7.9 min and reached a steady state after approximately 1 h. Thereafter, the release rate was constant and amounted to 2.6 +/- 0.3 pmol/min. During depolarization either with K+ (50 or 90 mM) or veratridine (1 or 10 microM), taurine outflow was increased in a concentration-dependent way. Hypothalamic superfusion with tetrodotoxin (1 microM) elicited a sustained decrease in the taurine release to 60% of the control values. Intravenous infusion of noradrenaline led to a rise in blood pressure (45 mm Hg) and enhanced the release of taurine in the hypothalamus. A fall of blood pressure (30 mm Hg) caused by an intravenous infusion of nitroprusside diminished taurine outflow. The results suggest that a considerable amount of the taurine detected is released from hypothalamic neurons. Changes in the release rate of taurine by experimentally induced alterations of blood pressure indicate that, in the posterior hypothalamus, the amino acid might play an important role as a neurotransmitter or neuromodulator possessing a hypotensive function.
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Affiliation(s)
- N Singewald
- Department of Pharmacology and Toxicology, University of Innsbruck, Austria
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