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Olson A, Zhang F, Cao H, Baranova A, Slavin M. In silico Gene Set and Pathway Enrichment Analyses Highlight Involvement of Ion Transport in Cholinergic Pathways in Autism: Rationale for Nutritional Intervention. Front Neurosci 2021; 15:648410. [PMID: 33958984 PMCID: PMC8093449 DOI: 10.3389/fnins.2021.648410] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Accepted: 03/22/2021] [Indexed: 12/12/2022] Open
Abstract
Food is the primary human source of choline, an essential precursor to the neurotransmitter acetylcholine, which has a central role in signaling pathways that govern sensorimotor functions. Most Americans do not consume their recommended amount of dietary choline, and populations with neurodevelopmental conditions like autism spectrum disorder (ASD) may be particularly vulnerable to consequences of choline deficiency. This study aimed to identify a relationship between ASD and cholinergic signaling through gene set enrichment analysis and interrogation of existing database evidence to produce a systems biology model. In gene set enrichment analysis, two gene ontologies were identified as overlapping for autism-related and for cholinergic pathways-related functions, both involving ion transport regulation. Subsequent modeling of ion transport intensive cholinergic signaling pathways highlighted the importance of two genes with autism-associated variants: GABBR1, which codes for the gamma aminobutyric acid receptor (GABAB 1), and KCNN2, which codes for calcium-activated, potassium ion transporting SK2 channels responsible for membrane repolarization after cholinergic binding/signal transmission events. Cholinergic signal transmission pathways related to these proteins were examined in the Pathway Studio environment. The ion transport ontological associations indicated feasibility of a dietary choline support as a low-risk therapeutic intervention capable of modulating cholinergic sensory signaling in autism. Further research at the intersection of dietary status and sensory function in autism is warranted.
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Affiliation(s)
- Audrey Olson
- Department of Nutrition and Food Studies, College of Health and Human Services, George Mason University, Fairfax, VA, United States
- School of Systems Biology, College of Science, George Mason University, Manassas, VA, United States
| | - Fuquan Zhang
- Department of Psychiatry, Nanjing Medical University, Nanjing, China
| | - Hongbao Cao
- School of Systems Biology, College of Science, George Mason University, Manassas, VA, United States
- Department of Psychiatry, Shanxi Medical University, Taiyuan, China
| | - Ancha Baranova
- School of Systems Biology, College of Science, George Mason University, Manassas, VA, United States
- Research Centre for Medical Genetics, Moscow, Russia
| | - Margaret Slavin
- Department of Nutrition and Food Studies, College of Health and Human Services, George Mason University, Fairfax, VA, United States
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Ercoli J, Miolan JP, Niel JP, Quinson N. Presynaptic GABA-A receptors prevent depression of nicotinic transmission in rabbit coeliac ganglion neurones. Eur J Neurosci 2007; 25:1307-18. [PMID: 17425557 DOI: 10.1111/j.1460-9568.2007.05382.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
We investigated the involvement of GABA-A receptors in the modulation of the nicotinic transmission of central origin in isolated rabbit coeliac ganglia. Our study was performed in vitro and the electrical activity of the ganglionic neurones was recorded using intracellular recording techniques. During iterative stimulation of the splanchnic nerves, the synaptic action potential probability decreased gradually, indicating a depression of the nicotinic activation. Pharmacological agents acting at GABA-A receptors modulated the action potential probability during the train of pulses. Muscimol (a GABA-A receptor agonist), diazepam (a benzodiazepine site agonist) and 1-[2-[[(diphenylmethylene)imino]oxy]ethyl]-1,2,5,6-tetrahydro-3-pyridinecarboxylic acid hydrochloride (a GABA uptake blocker) increased this probability. Conversely, gabazine or bicuculline (two GABA-A receptor antagonists), picrotoxin (a picrotoxin site agonist) and flumazenil (a benzodiazepine site antagonist) reduced it. These results demonstrate that endogenous GABA, released during the train of pulses, facilitates the central nicotinic activation of the ganglionic neurones by acting on GABA-A receptors. Muscimol also reduced the amplitude ratio of excitatory postsynaptic potentials triggered during the paired-pulse protocol without any change in postsynaptic properties. This result is consistent with a presynaptic action of GABA-A receptors. Our study shows that presynaptic GABA-A receptors facilitate the central nicotinic activation of prevertebral ganglionic neurones and thus play a novel role in the integrative properties of the sympathetic prevertebral ganglia.
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Affiliation(s)
- Jennifer Ercoli
- Laboratoire de Physiologie Neurovégétative, UMR Université Paul Cézanne Aix-Marseille III-CNRS-INRA, Faculté des Sciences et Techniques, 13397 Marseille cedex 20, France
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Cassano T, Carratù MR, Coluccia A, Di Giovanni V, Steardo L, Cuomo V, Trabace L. Preclinical progress with CHF2819, a novel orally active acetylcholinesterase inhibitor. Drug Dev Res 2002. [DOI: 10.1002/ddr.10088] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Trabace L, Cassano T, Loverre A, Steardo L, Cuomo V. CHF2819: pharmacological profile of a novel acetylcholinesterase inhibitor. CNS DRUG REVIEWS 2002; 8:53-69. [PMID: 12070526 PMCID: PMC6741681 DOI: 10.1111/j.1527-3458.2002.tb00215.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
CHF2819 is a novel orally active acetylcholinesterase inhibitor (AChEI) developed for the treatment of Alzheimer's disease (AD). CHF2819 is a selective inhibitor of AChE, it is 115 times more potent against this enzyme than against butyrylcholinesterase (BuChE). Moreover, CHF2819 is more selective for inhibition of central (brain) AChE than peripheral (heart) AChE. In vivo CHF2819, 0.5, 1.5, and 4.5 mg/kg p.o., significantly and in dose-dependent manner increased acetylcholine (ACh) levels in hippocampus of young adult rats. Moreover, aging animals, with lower basal ACh levels than young adult rats, also exhibit a marked increase in hippocampal levels of this neurotransmitter after administration of CHF2819. At 1.5 mg/kg p.o. CHF2819 attenuated scopolamine-induced amnesia in a passive avoidance task. Furthermore, it decreased dopamine (DA) levels and increased extracellular levels of 5-hydroxytryptamine (5-HT) in the hippocampus, without modifying norepinephrine (NE) levels. By oral administration to young adult rats CHF2819 did not affect extracellular hippocampal levels of glutamate (Glu), aspartate (Asp), gamma-aminobutyric acid (GABA), taurine (Tau), arginine (Arg) or citrulline (Cit). Functional observational battery (FOB) screening demonstrated that CHF2819 (1.5 and 4.5 mg/kg p.o.) does not affect activity, excitability, autonomic, neuromuscular, and sensorimotor domains, as well as physiological endpoints (body weight and temperature). CHF2819 induced, however, involuntary motor movements (ranging from mild tremors to myoclonic jerks) in a dose-dependent manner. The neurochemical and behavioral profiles of CHF2819 suggest that this orally active novel AChEI could be of clinical interest for the treatment of Alzheimer-type dementia associated with multiple neurotransmitter abnormalities in the brain. In particular, CHF2819 might be a useful therapeutic drug for AD patients with cognitive impairment accompanied by depression.
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Affiliation(s)
- Luigia Trabace
- Department of Pharmacology and Human Physiology, Medical School, University of Bari, Policlinico, Piazza Giulio Cesare 11, 70124 Bari, Italy.
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Materi LM, Semba K. Inhibition of synaptically evoked cortical acetylcholine release by intracortical glutamate: involvement of GABAergic neurons. Eur J Neurosci 2001; 14:38-46. [PMID: 11488947 DOI: 10.1046/j.0953-816x.2001.01619.x] [Citation(s) in RCA: 23] [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
Cortical acetylcholine (ACh) has been shown to regulate diverse cognitive processes and its release can be regulated by neuromodulators that act presynaptically at cholinergic terminals. The neocortex receives dense glutamatergic input from thalamocortical and other fibres. The present study used in vivo microdialysis to examine, and pharmacologically characterize, the effect of glutamate on cortical ACh release evoked by electrical stimulation of the pedunculopontine tegmental nucleus in urethane-anaesthetized rats. All drugs were administered locally within the cortex by reverse dialysis. Application of glutamate had no detectable effect on spontaneous ACh release but reduced evoked cortical ACh efflux in a concentration-dependent manner. This effect was mimicked by the glutamate transporter blocker L-trans-pyrrolidine-2,4-dicarboxylic acid, as well as by the ionotropic glutamate receptor agonists N-methyl-D-aspartic acid and alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid, and was blocked by the ionotropic glutamate receptor antagonists 6,7-dinitroquinoxaline-2,3-dione and (+/-)-3-(2-carboxypiperazin-4yl)-propyl-1-phosphonic acid. Glutamate application also increased extracellular adenosine levels but the simultaneous delivery of the broad-spectrum adenosine receptor antagonist caffeine failed to affect the inhibitory action of glutamate on evoked ACh release. However, the effect of glutamate was fully blocked by simultaneous delivery of the GABAA receptor antagonist bicuculline and partially blocked by the GABAB receptor antagonist phaclofen. These results suggest that ionotropic glutamate receptor activation by glutamate inhibits evoked cortical ACh release via an indirect pathway involving GABAergic neurons in the cortex.
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Affiliation(s)
- L M Materi
- Department of Anatomy and Neurobiology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia B3H-4H7, Canada
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Trabace L, Coluccia A, Gaetani S, Tattoli M, Cagiano R, Pietra C, Kendrick KM, Cuomo V. In vivo neurochemical effects of the acetylcholinesterase inhibitor ENA713 in rat hippocampus. Brain Res 2000; 865:268-71. [PMID: 10821930 DOI: 10.1016/s0006-8993(00)02266-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Oral ENA713 (0.5, 1.5 and 4.5 mg/kg), an acetylcholinesterase inhibitor (AChEI), dose-dependently enhanced extracellular acetylcholine concentrations in the hippocampus of freely moving rats. This effect was paralleled by changes in both noradrenergic and dopaminergic transmission. In particular, ENA713 significantly decreased noradrenaline concentrations, whereas it significantly increased homovanillic acid levels, without affecting dopamine concentrations. Neither serotonin nor gamma-aminobutyric acid levels were modified by ENA713. These findings extend the neurochemical profile of ENA713 and suggest that it could be useful for the treatment of Alzheimer-type dementia which is associated with multiple neurotransmitter abnormalities in the brain.
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Affiliation(s)
- L Trabace
- Department of Pharmacology and Human Physiology, Medical School, University of Bari, Policlinico-Piazza Giulio Cesare 11 70124, Bari, Italy
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Login IS, Pal SN, Adams DT, Gold PE. Muscimol increases acetylcholine release by directly stimulating adult striatal cholinergic interneurons. Brain Res 1998; 779:33-40. [PMID: 9473575 DOI: 10.1016/s0006-8993(97)01051-2] [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: 02/06/2023]
Abstract
Because GabaA ligands increase acetylcholine (ACh) release from adult striatal slices, we hypothesized that activation of GabaA receptors on striatal cholinergic interneurons directly stimulates ACh secretion. Fractional [3H]ACh release was recorded during perifusion of acutely dissociated, [3H]choline-labeled, adult male rat striata. The GabaA agonist, muscimol, immediately stimulated release maximally approximately 300% with EC50 = approximately 1 microM. This action was enhanced by the allosteric GabaA receptor modulators, diazepam and secobarbital, and inhibited by the GabaA antagonist, bicuculline, by ligands for D2 or muscarinic cholinergic receptors or by low calcium buffer, tetrodotoxin or vesamicol. Membrane depolarization inversely regulated muscimol-stimulated secretion. Release of endogenous and newly synthesized ACh was stimulated in parallel by muscimol without changing choline release. Muscimol pretreatment inhibited release evoked by K+ depolarization or by receptor-mediated stimulation with glutamate. Thus, GabaA receptors on adult striatal cholinergic interneurons directly stimulate voltage- and calcium-dependent exocytosis of ACh stored in vesamicol-sensitive synaptic vesicles. The action depends on the state of membrane polarization and apparently depolarizes the membrane in turn. This functional assay demonstrates that excitatory GabaA actions are not limited to neonatal tissues. GabaA-stimulated ACh release may be prevented in situ by normal tonic dopaminergic and muscarinic input to cholinergic neurons.
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Affiliation(s)
- I S Login
- Department of Neurology, University of Virginia Health Sciences Center, Charlottesville 22908, USA.
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Giovannini MG, Giovannelli L, Bianchi L, Kalfin R, Pepeu G. Glutamatergic modulation of cortical acetylcholine release in the rat: a combined in vivo microdialysis, retrograde tracing and immunohistochemical study. Eur J Neurosci 1997; 9:1678-89. [PMID: 9283822 DOI: 10.1111/j.1460-9568.1997.tb01525.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The microdialysis technique with one or two probes was used to investigate the modulation of cortically projecting cholinergic neurons by glutamatergic input in the rat in vivo. Male albino Wistar rats (250-300 g) were used. Under chloral hydrate anaesthesia microdialysis membranes were positioned in the parietal cortex, nucleus basalis magnocellularis (NBM) or medial septum. Acetylcholine was assayed using high-performance liquid chromatography (HPLC) with electrochemical detection while GABA was detected using HPLC with fluorimetric detection after derivatization of the amino acid with o-phthalaldehyde. Septo-cortical neurons were retrogradely labelled with fluoro-gold. Double labelling with choline acetyltransferase (ChAT) immunoreactivity was performed to identify these neurons. Our main findings were that: (i) i.c.v. administration of the NMDA antagonist 3-((R)-2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (CPP, 1-5 nmol) increased cortical acetylcholine outflow; (ii) local administration of CPP (100 microM) to the cortex had no effect on cortical acetylcholine outflow; (iii) local administration of CPP (100 microM) to the NBM decreased cortical acetylcholine outflow; (iv) local administration of CPP (100-200 microM) to the septum increased cortical GABA and acetylcholine outflow; (v) administration of muscimol to the septum prevented the effect of CPP on cortical acetylcholine outflow; (vi) retrograde tracing with fluoro-gold labelled cell bodies in the medial septum; (vii) septal fluoro-gold-positive neurons were not ChAT-immunoreactive. Our in vivo neurochemical results, in combination with retrograde tracing and immunohistochemistry, indicate that the cortically projecting cholinergic system is indirectly regulated by a glutamatergic input via a polysynaptic GABAergic circuitry located in the septum.
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Affiliation(s)
- M G Giovannini
- Department of Preclinical and Clinical Pharmacology, University of Florence, Italy
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9
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Ferraro L, Tanganelli S, Marani L, Bianchi C, Beani L, Siniscalchi A. Evidence for an in vivo and in vitro modulation of endogenous cortical GABA release by alpha-glycerylphosphorylcholine. Neurochem Res 1996; 21:547-52. [PMID: 8726961 DOI: 10.1007/bf02527751] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The effects of alpha-glycerylphosphorylcholine (alpha-GPC) on endogenous cortical GABA release were studied both in vivo and in vitro. In freely moving rats, equipped with epidural cups, alpha-GPC (30-300 mg/kg i.p.) increased GABA release. This effect was potentiated by atropine, both systematically administered (5 mg/kg i.p.) and locally applied (1.4 microM), but not by mecamylamine (4 mg/kg i.p.). The alpha-GPC-induced increase in GABA release was abolished in rats pretreated with the alpha 1 receptor antagonist prazosin (14 micrograms/kg i.p.). In cortical slices alpha-GPC (0.4 mM) increased the spontaneous GABA efflux. This effect was abolished by tetrodotoxin (0.5 microM) and prazosin (1 microM), but not by atropine (0.15 microM) or mecamylamine (2.5 microM). These results indicate that the facilitatory response by alpha-GPC on GABA release does not depend on a direct activation of either muscarinic or nicotinic receptors, but suggest the involvement of the noradrenergic system.
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Affiliation(s)
- L Ferraro
- Institute of Pharmacology, University of Ferrara, Italy
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O'Dell DM, Hamm RJ. Chronic postinjury administration of MDL 26,479 (Suritozole), a negative modulator at the GABAA receptor, and cognitive impairment in rats following traumatic brain injury. J Neurosurg 1995; 83:878-83. [PMID: 7472558 DOI: 10.3171/jns.1995.83.5.0878] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The present experiment examined the efficacy of postinjury administration of MDL 26,479 (Suritozole), a negative modulator at the gamma-aminobutyric acidA (GABAA) receptor that enhances cholinergic function, in attenuating spatial memory deficits after traumatic brain injury in the rat. Two experiments were performed. In the delayed-dosing experiment, rats received a moderate level (2.1 atm) of fluid-percussion brain injury and were tested in the Morris water maze 11 to 15 days following injury. These rats were injected with either 5 mg/kg (eight rats) or 10 mg/kg (eight rats) of MDL 26,479 60 minutes before each water maze test. Additional rats were injured and treated with saline (eight rats) or were surgically prepared but not injured (eight rats). In the second experiment, an early postinjury dosing procedure was followed. Rats were injured in the same manner but drug treatment began 24 hours after injury and continued daily through Day 15. Results indicated that the rats in the delayed chronic dosing regimen did not differ from the injured, saline-treated rats in their latency to reach the goal platform (p > 0.05). However, those treated chronically beginning 24 hours after injury had significantly shorter latencies than the injured, saline-treated rats (p < 0.05). These results suggest that administration of agents that enhance cholinergic function may be an appropriate strategy for promoting cognitive recovery when given after traumatic brain injury. Furthermore, prolonged treatment may be necessary to elicit beneficial effects.
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Affiliation(s)
- D M O'Dell
- Department of Psychology, Virginia Commonwealth University, Richmond, USA
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El-Kadi AO, Sharif SI. Modification by muscimol of naloxone-precipitated withdrawal symptoms in morphine-dependent mice. GENERAL PHARMACOLOGY 1995; 26:1579-81. [PMID: 8690249 DOI: 10.1016/0306-3623(95)00053-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
1. In morphine-dependent mice, muscimol, a GABAA agonist when given i.p. 30 min before naloxone, attenuated the naloxone-precipitated withdrawal symptoms of jumping, "wet dog" shakes and burrowing, but not body weight loss. 2. Muscimol produced a hypothermic effect which was further aggravated by naloxone.
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Affiliation(s)
- A O El-Kadi
- Department of Pharmacology, Al-Arab Medical University, Benghazi, Libya
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12
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Parkman HP, Stapelfeldt WH, Williams CL, Lennon VA, Szurszewski JH. Enteric GABA-containing nerves projecting to the guinea-pig inferior mesenteric ganglion modulate acetylcholine release. J Physiol 1993; 471:191-207. [PMID: 8120803 PMCID: PMC1143958 DOI: 10.1113/jphysiol.1993.sp019897] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
1. The effect of GABA and GABA receptor-modulating drugs on release of [3H]acetylcholine was studied in the guinea-pig inferior mesenteric ganglion. 2. GABA caused a dose-dependent increase in [3H]acetylcholine release during stimulation of the lumbar colonic nerves. Muscimol (10 microM) and diazepam (5 microM) also increased [3H]acetylcholine release during stimulation of the lumbar colonic nerves whereas baclofen (10 microM) had no effect. 3. Bicuculline (20-100 microM) and picrotoxin (50 microM) alone reduced [3H]acetylcholine release during electrical stimulation of the lumbar colonic nerves whereas phaclofen (300 microM) had no effect. 4. Bicuculline (100 microM) significantly decreased whereas diazepam (5 microM) significantly increased distension-induced [3H]acetylcholine release. 5. Colonic distension significantly increased [3H]GABA release in the inferior mesenteric ganglion compared to basal periods when the colon was not distended. Distension-induced release of [3H]GABA resulted from active neuronal transmission from the colon to the inferior mesenteric ganglion, since perfusion of the inferior mesenteric ganglion with tetrodotoxin (1 microM) reduced basal release of [3H]GABA and abolished distension-evoked increases in the release of [3H]GABA. 6. In contrast to its excitatory effects on peripheral colonic afferent cholinergic nerves, exogenous GABA caused a dose-dependent decrease in [3H]acetylcholine release during electrical stimulation of the central lumbar splanchnic nerves. Baclofen (10 microM) also inhibited [3H]acetylcholine release whereas muscimol (10 microM) or diazepam (5 microM) had no effect. Phaclofen (300 microM) antagonized the inhibitory effects of exogenous GABA (10 microM) and of baclofen (10 microM). Bicuculline (100 microM), picrotoxin (50 microM) and phaclofen (300 microM) alone had no effect on [3H]acetylcholine release during splanchnic nerve stimulation. 7. Phaclofen (300 microM) increased [3H]acetylcholine release during simultaneous electrical stimulation of the lumbar colonic nerves and splanchnic nerves and when GABAA receptors were blocked by bicuculline (20 microM). 8. The data suggest that GABAA receptors facilitate release of acetylcholine from peripheral cholinergic mechanosensory nerves projecting from the colon to the inferior mesenteric ganglion and that GABAB receptors inhibit release of acetylcholine from central cholinergic nerves. Enteric GABA-containing nerves projecting to the inferior mesenteric ganglion are mechanosensory. Endogenous release of GABA may act on GABAA receptors to facilitate peripheral cholinergic mechanosensory transmission and/or on GABAB receptors to inhibit central cholinergic transmission.
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Affiliation(s)
- H P Parkman
- Department of Physiology and Biophysics, Mayo Clinic, Rochester, MN 55905
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Rada PV, Mark GP, Hoebel BG. In vivo modulation of acetylcholine in the nucleus accumbens of freely moving rats: II. Inhibition by gamma-aminobutyric acid. Brain Res 1993; 619:105-10. [PMID: 8397051 DOI: 10.1016/0006-8993(93)91601-n] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Our earlier studies suggest dopamine and serotonin interact with acetylcholine (ACh) in the nucleus accumbens (NAC) as part of a system for motivation and reinforcement. The purpose of the present experiment was to characterize a possible link between GABA and acetylcholine in the nucleus accumbens using microdialysis in freely moving rats. Different doses of GABA, muscimol, baclofen, saclofen and bicuculline were locally infused into the nucleus accumbens through the microdialysis probe. GABA and its agonists dose-dependently decreased extracellular levels of acetylcholine in the nucleus accumbens. In contrast the GABAA antagonist, bicuculline, dose-dependently increased extracellular ACh while the GABAB antagonist, saclofen, was without effect. Co-infusion of bicuculline or saclofen was shown to block the decrease in recoverable ACh produced by muscimol or baclofen, respectively. The results demonstrate an inhibitory action of GABA on acetylcholine interneurones in the nucleus accumbens involving both GABAA and GABAB receptor subtypes. In addition a tonic inhibitory GABAergic tone is probably mediated through GABAA receptors.
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Affiliation(s)
- P V Rada
- Department of Psychology, Princeton University, NJ 08544-1010
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14
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Bonanno G, Ruelle A, Andrioli GC, Raiteri M. Cholinergic nerve terminals of human cerebral cortex possess a GABA transporter whose activation induces release of acetylcholine. Brain Res 1991; 539:191-5. [PMID: 2054596 DOI: 10.1016/0006-8993(91)91620-g] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The effect of gamma-aminobutyric acid (GABA) on the release of [3H]acetylcholine [( 3H]ACh) from human cerebral cortex nerve terminals was investigated using synaptosomes prepared from neurosurgical specimens (which had to be removed to reach deeply located tumors) prelabeled with [3H]choline and exposed in superfusion to varying concentrations of GABA. The amino acid (3-100 microM) increased in a concentration-dependent manner (maximal effect: 40%; EC50 = 14.7 microM) the release of [3H]ACh but not that of [3H]choline. The GABAA receptor agonist muscimol (up to 100 microM) did not increase significantly the release of [3H]ACh. Accordingly, the effect of GABA was insensitive to the GABAA receptor antagonist bicuculline. The release of [3H]ACh was not affected by the GABAB receptor agonist (-)-baclofen (100-300 microM). The GABA-induced [3H]ACh release was counteracted by two inhibitors of GABA uptake, N-(4,4-diphenyl-3-butenyl)nipecotic acid (SKF 89976A) and nipecotic acid. Moreover, the enhancing effect of GABA on [3H]ACh release was clearly Na+-dependent and was reduced by almost 90% in presence of 23 mM NaCl. The data indicate that, similarly to what had been observed in the rat, cholinergic nerve terminals in the human cerebral cortex possess a GABA transporter. Activation of this carrier brings about release of newly synthesized ACh. GABA and ACh might co-exist in some cerebrocortical nerve endings in the vertebrate brain, including man.
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Affiliation(s)
- G Bonanno
- Instituto di Farmacologia e Farmacognosia, Università degli Studi di Genova, Italy
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15
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Abe E. Reversal effect of DM-9384 on scopolamine-induced acetylcholine depletion in certain regions of the mouse brain. Psychopharmacology (Berl) 1991; 105:310-6. [PMID: 1798828 DOI: 10.1007/bf02244423] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The effect of a new cognition enhancer, DM-9384, N-(2,6-dimethylphenyl)-2-(2-oxo-1-pyrrolidinyl) acetamide, on regional acetylcholine (ACh) levels and against scopolamine-induced ACh depletion was examined in mouse brain. In addition, the effects of DM-9384 were compared with those of oxiracetam, physostigmine and tacrine. Independent administration of DM-9384 (1, 3, 10 or 30 mg/kg, PO) or oxiracetam (10 or 50 mg/kg, PO) to mice had no effect on the ACh level in the hippocampus, frontal cortex, amygdala and striatum. Nevertheless, in all brain regions, pretreatment with DM-9384 significantly reduced the depletion of ACh induced by scopolamine (0.5 mg/kg, IP) in a nondose-related bell-shaped manner. By contrast, oxiracetam attenuated the effect of scopolamine in the hippocampus, frontal cortex and striatum but not in the amygdala. Physostigmine (0.2 mg/kg, SC) significantly increased ACh levels and reversed the scopolamine-induced ACh depletion in all brain regions. Unlike physostigmine, tacrine (10 mg/kg, PO) increased ACh levels in the striatum but not in the other regions. Tacrine reversed the effect of scopolamine in the hippocampus, amygdala and striatum, but not in the frontal cortex. In the present study, DM-9384 more effectively inhibited scopolamine-induced depletion of ACh levels than the other agents tested. The results obtained indicate that the protective action of DM-9384 against scopolamine-induced amnesia is due to its ability to reverse the ACh depletion.
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Affiliation(s)
- E Abe
- Department of Pharmacology, School of Dentistry, Iwate Medical University, Morioka, Japan
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Marchi M, Sanguineti P, Raiteri M. Muscarinic receptors mediate direct inhibition of GABA release from rat striatal nerve terminals. Neurosci Lett 1990; 116:347-51. [PMID: 2243614 DOI: 10.1016/0304-3940(90)90099-u] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The effects of acetylcholine (ACh) on the depolarization-evoked release of [3H]gamma-aminobutyric acid ([3H]GABA) have been investigated using synaptosomes prepared from rat corpus striatum and depolarized by superfusion with 9 mM KCl. Acetylcholine inhibited the [3H]GABA overflow in a concentration-dependent manner. The maximal effect was about 50%. The IC50 value (concentration producing half-maximal effect) amounted to 1 microM, in the absence of acetylcholinesterase inhibitors. The effect of ACh on the K(+)-evoked [3H]GABA release was counteracted by the muscarinic receptor antagonist atropine, but not by the nicotinic receptor antagonist mecamylamine or by the selective M1 antagonist pirenzepine. The data show that muscarinic receptors with low affinity for pirenzepine are localized on GABAergic nerve endings in rat corpus striatum where they may directly inhibit the release of GABA.
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Affiliation(s)
- M Marchi
- Istituto di Farmacologia e Farmacognosia, Università degli Studi di Genova, Italy
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17
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Nabeshima T, Tohyama K, Ichihara K, Kameyama T. Attenuation of benzodiazepine-induced passive avoidance deficit by post-training administration of muscimol: interaction with the cholinergic neuronal system. Eur J Pharmacol 1990; 182:555-60. [PMID: 1977593 DOI: 10.1016/0014-2999(90)90055-b] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We examined the involvement of GABAergic neuronal systems in benzodiazepine-induced passive avoidance deficit. Chlordiazepoxide impaired the passive avoidance response dose dependently when it was given prior to training. Post-training administration of muscimol improved the performance of chlordiazepoxide-pretreated mice. The effects of muscimol were antagonized completely by the GABAA antagonist, bicuculline, and the muscarinic acetylcholine receptor antagonist, scopolamine, but not by the benzodiazepine receptor antagonist, flumazenil, when the latter was administered immediately after training. It appears from these results that the GABAergic neuronal system plays an important role in the benzodiazepine-induced passive avoidance deficit by interacting with the cholinergic neuronal system.
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Affiliation(s)
- T Nabeshima
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Meijo University, Nagoya, Japan
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18
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Friedman E, Wang HY, Butkerait P. Decreased striatal release of acetylcholine following withdrawal from long-term treatment with haloperidol: modulation by cholinergic, dopamine-D1 and -D2 mechanisms. Neuropharmacology 1990; 29:537-44. [PMID: 2200974 DOI: 10.1016/0028-3908(90)90065-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The effect of chronic treatment with haloperidol (2.7-5.3 mumol/kg/day) on K(+)-evoked release of [3H]acetylcholine (ACh) from superfused slices of the striatum was assessed. Acute injections of haloperidol (0.7-13.3 mumol/kg) produced 5-54% increases in the release of [3H]ACh in the striatum. Chronic treatment with haloperidol for 2.5 and 5 months also resulted in enhanced release of [3H]ACh in the striatum (28-35%). However, withdrawal from 2.5 and 5 months of treatment produced 34 and 38% decreases in K(+)-evoked release of [3H]ACh in the striatum, respectively. The drug SKF 38393 (D1-agonist), produced concentration-dependent (0.1-10 microM) increases (24-59%) in the release of [3H]ACh in the striatum which were blocked by the selective D1-antagonist, SCH 23390. The effect of stimulation of D1-receptors was significantly reduced after 2.5 or 5 months of chronic treatment with haloperidol. Both LY171555 (D2-agonist) and carbachol (muscarinic agonist) produced concentration-dependent (0.1-10 microM) inhibitions of the release of [3H]ACh in the striatum (LY171555: 28-62%; carbachol: 23-63%). Long-term treatment with haloperidol (2.5 and 5 months) elicited increases in sensitivity to the effect of LY171555, while the effect of carbachol was diminished only after the 5-month treatment period. These findings demonstrate that withdrawal from chronic exposure to haloperidol in the rat results in a reduction in the release of acetylcholine in the striatum. This effect is accompanied by (1) attenuated dopaminergic D1 mechanisms which ordinarily facilitate evoked release of ACh, (2) enhanced D2 mechanism which elicits inhibition of the release of ACh in the striatum, and (3) diminished muscarinic inhibitory influence which regulates the release of ACh.
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Affiliation(s)
- E Friedman
- Department of Psychiatry, Medical College of Pennsylvania/EPPI, Philadelphia 19129
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19
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Alberch J, Arenas E, Sánchez Arroyos R, Marsal J. Excitatory amino acids release endogenous acetylcholine from rat striatal slices: Regulation by gamma-aminobutyric acid. Neurochem Int 1990; 17:107-16. [DOI: 10.1016/0197-0186(90)90074-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/1989] [Accepted: 01/23/1990] [Indexed: 11/17/2022]
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Pepeu G, Casamenti F, Giovannini MG, Vannucchi MG, Pedata F. Principal aspects of the regulation of acetylcholine release in the brain. PROGRESS IN BRAIN RESEARCH 1990; 84:273-8. [PMID: 2267302 DOI: 10.1016/s0079-6123(08)60911-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- G Pepeu
- Department of Preclinical and Clinical Pharmacology, University of Florence, Italy
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21
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Wetherell JR, Fosbraey P, French MC. A comparison of the distribution of neurotransmitters in brain regions of the rat and guinea-pig using a chemiluminescent method and HPLC with electrochemical detection. J Neurochem 1989; 53:1519-26. [PMID: 2571676 DOI: 10.1111/j.1471-4159.1989.tb08547.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Six brain areas of rats and guinea-pigs, killed by microwave irradiation, were used for the concomitant measurement of the levels and regional distribution of cholinergic, biogenic amine, and amino acid neurotransmitters and metabolites. Acetylcholine (ACh) and choline (Ch) were quantified by chemiluminescence; noradrenaline (NA), dopamine (DA), 5-hydroxytryptamine (5-HT), and their metabolites by HPLC with electrochemical detection (HPLC-EC); and six putative amino acid neurotransmitters by HPLC-EC following derivatisation. The levels and regional distribution of these transmitters and their metabolites in the rat were similar to those reported in previous studies, except that biogenic amine transmitter levels were higher and metabolite concentrations were lower. The guinea-pig showed a similar regional distribution, but the absolute levels of ACh were lower in striatum and higher in hippocampus, midbrain-hypothalamus, and medulla-pons. In all areas, the levels of Ch were higher and those of NA, 5-HT, and taurine were lower than in the rat. The most marked differences between the rat and guinea-pig were in the relative proportion of DA metabolites and 5-HT turnover, as estimated by metabolite/transmitter ratios. This study can be used as a basis for a comprehensive understanding of the central effects of drugs on the major neurotransmitter systems.
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Affiliation(s)
- J R Wetherell
- Biology Division, Chemical Defence Establishment, Porton Down, Salisbury, Wiltshire, England, U.K
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22
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Bianchi C, Siniscalchi A, Beani L. Effect of 5-hydroxytryptamine on [3H]-acetylcholine release from guinea-pig striatal slices. Br J Pharmacol 1989; 97:213-21. [PMID: 2566351 PMCID: PMC1854455 DOI: 10.1111/j.1476-5381.1989.tb11944.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
1. The effect of 5-hydroxytryptamine (5-HT) on spontaneous and electrically-evoked tritium efflux was studied in guinea-pig caudate nucleus slices preloaded with [3H]-choline. 2. 5-HT, 10-300 mumol l-1, temporarily increased the spontaneous tritium efflux (as well as the endogenous acetylcholine (ACh) release) and, after 15 min perfusion, inhibited it. The facilitatory effect of 5-HT on spontaneous efflux was increased while the inhibitory effect did not occur in slices taken from dopamine-depleted guinea-pigs. 3. The increase in spontaneous tritium efflux by 5-HT was blocked by methiothepin, methysergide (pA2 8.7) and by the selective 5-HT2 antagonist, ritanserin (pA2 6.7). 4. The inhibition of spontaneous tritium efflux by 5-HT was prevented by methysergide and methiothepin but not by ritanserin and (-)-propranolol. 5. 5-HT, 100 mumol l-1, inhibited the electrically-evoked tritium efflux and this effect was unchanged in dopamine-depleted slices. 6. The inhibition of electrically-evoked tritium efflux by 5-HT was blocked by methiothepin and methysergide but not by (-)-propranolol or ritanserin. 7. These results suggest that 5-HT may exert a rapid and transient (excitatory) and a more prolonged (inhibitory) control over striatal cholinergic neurones.
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Affiliation(s)
- C Bianchi
- Department of Pharmacology, University of Ferrara, Italy
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23
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Bonanno G, Raiteri M. Regional selectivity of a gamma-aminobutyric acid-induced [3H]acetylcholine release sensitive to inhibitors of gamma-aminobutyric acid uptake. J Neurochem 1987; 48:1454-8. [PMID: 3559559 DOI: 10.1111/j.1471-4159.1987.tb05685.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The effects of gamma-aminobutyric acid (GABA) on the release of [3H]acetylcholine ([3H]ACh) were studied in synaptosomes prepared from rat hippocampus, cerebral cortex, hypothalamus, and striatum and prelabelled with [3H]choline. When synaptosomes were exposed in superfusion to exogenous GABA (0.01-0.3 mM) the basal release of newly synthesized [3H]ACh was increased in a concentration-dependent way in hippocampus, cortex, and hypothalamus nerve endings. In contrast, the release of [3H]ACh was not significantly affected by GABA in striatal synaptosomes. The effect of GABA was not antagonized significantly by bicuculline or picrotoxin. Muscimol caused only a slight not significant increase of [3H]ACh release when tested at 0.3 mM whereas, at this concentration, (-)-baclofen was totally inactive. The GABA-induced release of [3H]ACh was counteracted by SKF 89976A, SKF 100561, and SKF 100330A, three strong and selective GABA uptake inhibitors. The data suggest that, in selective areas of the rat brain, GABA causes release of [3H]ACh following penetration into cholinergic nerve terminals through a GABA transport system.
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24
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Frigo GM, Galli A, Lecchini S, Marcoli M. A facilitatory effect of bicuculline on the enteric neurones in the guinea-pig isolated colon. Br J Pharmacol 1987; 90:31-41. [PMID: 3028560 PMCID: PMC1917270 DOI: 10.1111/j.1476-5381.1987.tb16822.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Changes in the efficiency of the peristaltic reflex, acetylcholine (ACh) output and motor responses to transmural and periarterial nerve stimulation produced by bicuculline and gamma-aminobutyric acid (GABA) receptor desensitization were investigated in the guinea-pig isolated colon. Bicuculline, at concentrations unable to affect spontaneous colonic motility and lacking anticholinesterase activity, produced a dose-dependent increase of both the efficiency of the peristaltic reflex and the stimulated ACh output. Such effects could not be observed in GABA-desensitized preparations. A frequency-dependent potentiation of the cholinergic excitatory and non-adrenergic non-cholinergic (NANC) inhibitory responses to transmural stimulation was also observed in the presence of bicuculline. Conversely bicuculline exhibited an inhibitory effect on the relaxation induced by periarterial nerve stimulation. Acute GABA-desensitization was unable to affect the contractile responses to transmural stimulation, the ACh output and the efficiency of the peristaltic reflex. On the contrary, desensitization was able to mimic the effects of bicuculline on the inhibitory responses to both transmural and periarterial nerve stimulation. Our results are consistent with a significant role played by an intrinsic GABAergic pathway in the modulation of both cholinergic excitatory and NANC inhibitory neurones. The hypothesis is advanced that a feed-back modulation carried out through bicuculline-sensitive GABAergic synapses could operate during the propagation of peristaltic motor activity.
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25
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Antonelli T, Beani L, Bianchi C, Rando S, Simonato M, Tanganelli S. Cortical acetylcholine release is increased and gamma-aminobutyric acid outflow is reduced during morphine withdrawal. Br J Pharmacol 1986; 89:853-60. [PMID: 3814913 PMCID: PMC1917220 DOI: 10.1111/j.1476-5381.1986.tb11191.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The effects of naloxone on acetylcholine (ACh) and gamma-aminobutyric acid (GABA) outflow from the cerebral cortex of freely moving, morphine-dependent guinea-pigs was studied. The cortical efflux of ACh in chronically-treated guinea-pigs was about half of that of normal animals. GABA efflux was unaffected. During opioid withdrawal precipitated by naloxone (0.1-10 mg kg-1, i.p.) the guinea-pigs showed jumping, hyperactivity and wet dog shakes, the intensity of which was directly related to the dose of naloxone. The withdrawal syndrome was accompanied by a dose-dependent increase in ACh release and reduction in GABA outflow; ACh release was increased by naloxone at doses lower (0.1-3 mg kg-1) than those acting on GABA efflux (1-10 mg kg-1). Atropine (10 mg kg-1) and diazepam (5 mg kg-1) did not prevent GABA and ACh changes.
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26
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Bonanno G, Raiteri M. GABA enhances acetylcholine release from hippocampal nerve endings through a mechanism blocked by a GABA uptake inhibitor. Neurosci Lett 1986; 70:360-3. [PMID: 3022197 DOI: 10.1016/0304-3940(86)90579-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The effect of gamma-aminobutyric acid (GABA) on the release of [3H]acetylcholine [( 3H]ACh) was investigated using superfused rat hippocampal synaptosomes. GABA enhanced the basal efflux of [3H]ACh. The effect of GABA was bicuculline-insensitive. Muscimol, (+/-)-baclofen or (-)-baclofen did not increase [3H]ACh release. The effect of GABA was counteracted by SK&F 89976 A (N-(4,4-diphenyl-3-butenyl)-nipecotic acid), a GABA uptake inhibitor. One possible interpretation of the results is that a GABA transport system is present on cholinergic terminals, suggesting that GABA and ACh may coexist in some rat hippocampus nerve endings. Another possibility is that the effect of GABA is mediated by a novel subtype of GABA receptor sensitive to SK&F 89976 A.
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27
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Bianchi C, Siniscalchi A, Beani L. The influence of 5-hydroxytryptamine on the release of acetylcholine from guinea-pig brain ex vivo and in vitro. Neuropharmacology 1986; 25:1043-9. [PMID: 2945999 DOI: 10.1016/0028-3908(86)90200-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The effect of 5-hydroxytryptamine (5-HT) on the release of acetylcholine (ACh) from the brain of the guinea-pig was investigated in order to determine whether this amine plays a modulatory role on the cortical cholinergic projections. 5-Hydroxytryptamine (0.2-1 mumol), injected intracerebroventricularly (i.c.v.), caused mild excitation, stereotyped movements and ataxia. Simultaneously, it increased the output of ACh from the cortex in a dose-dependent manner. Methysergide (4.2 mumol Kg-1 i.p.) also increased the output of ACh by about 60-80%, but prevented the effect of 5-HT (1 mumol i.c.v.). Metitepine (1-4.2 mumol kg-1 i.p.) increased the output of ACh like methysergide but it changed the facilitation of the release of ACh by 5-HT into inhibition. At the same time the animals became hypothermic, sedated and their electroencephalogram (EEG) was synchronized. Pretreatment with 5,7-HT blocked the increase in release of ACh produced by 5-HT (1 mumol). D-Norfenfluramine (10.4 mumol kg-1) was ineffective alone but reduced the release of ACh in metitepine-pretreated animals. 5-Hydroxytryptamine (10-30 microM) did not affect the efflux of [3H]choline from electrically-stimulated slices of cerebral cortex. The increase in the release of ACh caused by 5-HT, abolished by pretreatment with methysergide and 5,7-HT, may be explained by activation of 5-HT autoreceptors, while the increase of transmitter outflow induced by methysergide may be due to a blockade of 5-HT receptors present on the cholinergic neurones. Metitepine appeared to unmask the tryptaminergic inhibition caused by injection of 5-HT intraventricularly or by the 5-HT-releasing drug, D-norfenfluramine, possibly by acting on the autoreceptors and preventing auto-inhibition.(ABSTRACT TRUNCATED AT 250 WORDS)
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28
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Robinson SE, Rice MA, Hambrecht KL. Effect of intrastriatal injection of diisopropylfluorophosphate on acetylcholine, dopamine, and serotonin metabolism. J Neurochem 1986; 46:1632-8. [PMID: 2420935 DOI: 10.1111/j.1471-4159.1986.tb01786.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Diisopropylfluorophosphate (81.5 nmol) was injected directly into the striata of rats to study changes in striatal metabolism of acetylcholine (ACh), 3,4-dihydroxyphenylethylamine (dopamine), and 5-hydroxytryptamine (serotonin) at early time points following acute irreversible inhibition of cholinesterase. Twenty minutes following the intrastriatal injection of diisopropylfluorophosphate, levels of striatal acetylcholine were elevated by 50%, but a decrease in KACh compensated for this change. At 1 h, levels of ACh were still elevated, but not significantly different from control values. However, KACh and, hence, ACh turnover were greatly enhanced at this time. Finally, at 24 h, striatal ACh content was only slightly elevated and KACh and the turnover rate of ACh had returned to control values. Striatal cholinesterase activity remained significantly inhibited at all three times. At none of these times was ACh content or turnover affected in the parietal cortex, hippocampus, hypothalamus, or medulla/pons. Neither dopamine and its metabolites 3,4-dihydroxyphenylacetic acid and homovanillic acid nor serotonin and its metabolite 5-hydroxyindoleacetic acid were significantly affected at any of the three times by intrastriatal diisopropylfluorophosphate treatment. Possible mechanisms of the changes in cholinergic parameters are discussed.
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Kitayama S, Morita K, Dohi T, Tsujimoto A. Potassium ion is indispensable to the catecholamine releasing response of dog adrenals to gamma-aminobutyric acid. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 1986; 332:66-9. [PMID: 3951566 DOI: 10.1007/bf00633199] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The effect of potassium ion on the GABA-evoked catecholamine (CA) release from isolated perfused adrenal glands of the dog was investigated. When omitting the external potassium ion, the basal release of CA was increased. During this period GABA no longer caused the increase in CA release and moreover the increased basal release was diminished reversibly by GABA. 3-Amino-1-propane-sulfonic acid, a GABAA agonist, mimicked the action of GABA in K+-free solution, while baclofen, a GABAB agonist, did not cause CA release in normal solution and did not alter the basal release in K+-free solution. The inhibition by GABA of the basal CA release in K+-free solution was blocked by bicuculline. The potency of the CA releasing action of GABA was dependent on the concentration of external K+ between 1-10 mM. Reintroduction of K+ to glands which had been perfused with K+-free solution immediately reduced the basal release of CA whereas it recovered the CA releasing action of GABA. These results suggest that GABA-evoked CA release is dependent on potassium ion. The possible mechanisms by which GABA evoked CA release are discussed.
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30
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Serrano JS, Miñano FJ, Sancibrián M. GABA-induced hypothermia in rats: involvement of serotonergic and cholinergic mechanisms. GENERAL PHARMACOLOGY 1986; 17:327-32. [PMID: 2941336 DOI: 10.1016/0306-3623(86)90048-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The effects of gamma-aminobutyric acid (GABA) on body temperature of restrained rats has been studied. GABA (250-1000 mg/kg i.p.) caused a dose-dependent fall in BT of restrained rats at an ambient temperature of 18-22 degrees C. The GABA-induced hypothermic response was attenuated by pretreatment with hexamethonium, p-chlorophenylalanine, methysergide, neostigmine and atropine (% MPE values: 27, 35, 51, 64 and 72 respectively). Pretreatment with methysergide and atropine was more potent than hexamethonium and methysergide in inhibiting the GABA-induced hypothermia (% MPE = 68 and 47 respectively). The antagonism by neostigmine of GABA-induced hypothermia was attenuated by pretreatment with hexamethonium (7.5 mg/kg). Yohimbine and chlorimipramine potentiated GABA hypothermia (% MPE = -82 and -8 respectively). The data indicate that GABA-induced hypothermia may be mediated by serotonin and acetylcholine release. Muscarinic receptors may play an important role in the effect of GABA. The results support the hypothesis that the hypothermia induced by GABA is modulated by nicotinic receptors.
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31
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Tanganelli S, Bianchi C, Beani L. The modulation of cortical acetylcholine release by GABA, GABA-like drugs and benzodiazepines in freely moving guinea-pigs. Neuropharmacology 1985; 24:291-9. [PMID: 2860590 DOI: 10.1016/0028-3908(85)90134-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
In order to define the modulatory role played by gamma-aminobutyric acid (GABA) in corticopetal cholinergic projections, the effect of this amino acid and related drugs on gross behaviour, the EEG and the release of acetylcholine (ACh) from the cerebral cortex in freely moving guinea-pigs was studied. gamma Aminobutyric acid, injected intracerebroventricularly (20-50 mumol) induced a three-phase picture: first (5-15 min) behavioural activation and increased release of ACh, then (30-90 min) depression, EEG synchronization and reduced release of ACh, and finally "rebound" stimulation. Ethanolamine-O-sulphate (EOS) injected intraventricularly (28 mumol/kg) or intraperitoneally (14 mmol/kg) reproduced the first two phases of the effects of GABA (i.e. stimulation followed by inhibition), while diazepam (0.7 and 3.5 mumol/kg, i.p.) and flurazepam (32 mumol/kg, i.p.) caused, at first, only depression. Muscimol and 4,5,6,7-tetrahydroisoxazolo(4,5-c)pyridine-3-ol (THIP) injected intraventricularly (in the nmol range) or intraperitoneally (in the mumol range) produced behavioural activation and increased release of ACh; the depressant signs appeared only after very large, toxic doses. Picrotoxin and bicuculline, at sub-convulsive doses, reduced the symptomatology caused by GABA and antagonized the sedation produced by diazepam. Methysergide (8-16 mumol/kg, i.p.) prevented the behavioural activation and the increased release of ACh by GABA, unmasked the depression due to subthreshold doses of diazepam (i.c.v., 7-70 nmol) and reversed the stimulation induced by muscimol into sedation and reduced the outflow of ACh. Pretreatment with 5,7-HT also dampened and shortened the stimulation by muscimol.(ABSTRACT TRUNCATED AT 250 WORDS)
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32
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Fogel R, Kaplan RB, Arbit E. Central action of gamma-aminobutyric acid ligands to alter basal water and electrolyte absorption in the rat ileum. Gastroenterology 1985; 88:523-30. [PMID: 3965342 DOI: 10.1016/0016-5085(85)90516-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The gamma-aminobutyric acid agonist muscimol and the gamma-aminobutyric acid antagonist bicuculline were studied to determine their effects on basal net water and electrolyte transport in the rat ileum. Whereas the intraperitoneal injection of muscimol caused a reversible, dose-dependent decrease in net water absorption, bicuculline produced a reversible, dose-dependent increase in net water and ion absorption. The threshold doses of muscimol and bicuculline were greater than 2.1 and 2.2 micrograms/kg, respectively. Lower doses of muscimol (0.1 microgram) or bicuculline (0.3 microgram) administered into the cerebrospinal fluid had the same effect as higher doses given systemically. Vagotomy prevented the effect of intracerebroventricular muscimol. Atropine (6 micrograms intracerebroventricularly) alone did not alter basal water absorption but abolished the muscimol effect, suggesting that muscimol promoted the release of acetylcholine from central cholinergic neurons. Atropine did not prevent the bicuculline effect. We conclude that (a) muscimol decreases ileal water absorption and bicuculline enhances ileal water absorption by an action at a gamma-aminobutyric acid receptor in the central nervous system, (b) the muscimol effect is due to an alteration in parasympathetic vagal outflow to the intestine, (c) the muscimol effect is mediated by a central cholinergic interneuron, and (d) the bicuculline effect is not mediated by the release of acetylcholine from central cholinergic neurons.
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33
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Beani L, Bianchi C, Siniscalchi A, Sivilotti L, Tanganelli S, Veratti E. Different approaches to study acetylcholine release: endogenous ACh versus tritium efflux. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 1984; 328:119-26. [PMID: 6527702 DOI: 10.1007/bf00512060] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Superfused slices of guinea-pig cerebral cortex (CC), caudate nucleus (CN) and thalamus (Th) were used to compare i) the resting and electrically-evoked release of endogenous acetylcholine (ACh) in the presence of physostigmine (Phys) and ii) the resting and electrically-evoked tritium efflux (after preloading with 3H choline) in the absence or in the presence of Phys and hemicholinium (HC-3). In addition, the effect of GABA, morphine and their antagonists on both effluxes was investigated. By matching the ACh and tritium outflow on a molar basis, an average ratio of 100: 2-4 was found. When expressed as a percentage of tissue content, the ACh release at 2 Hz (2 min) was 4.1 in CN, 0.92 in CC and 0.44 in Th. Lower percent values in the same rank order, were found for tritium outflow with Phys. Thus, CN has the highest secretory activity. Tritium evoked outflow in the presence of Phys was nearly halved in comparison with the normal values (without Phys). Therefore, the autoreceptor-mediated negative feed-back seems to be similar in the three areas. Tritium evoked outflow in the presence of HC-3 was more than doubled in Th (less so in CC and CN) in comparison with the normal values. A second stimulation at 2 Hz (2 min) gave rise to the same outflow in Th while an evident fall in radiolabel efflux was found in CN. Therefore the blockade of high affinity choline uptake plays a different role in Th and CN.(ABSTRACT TRUNCATED AT 250 WORDS)
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Antonelli T, Caciagli F, Lambertini L, Veratti E, Bianchi C. Effect of gamma-aminobutyric acid on cyclic nucleotides content of guinea-pig cerebral cortex slices. PHARMACOLOGICAL RESEARCH COMMUNICATIONS 1984; 16:933-43. [PMID: 6095333 DOI: 10.1016/s0031-6989(84)80030-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The effect of GABA and related drugs on 3'5' cAMP and 3'5' cGMP was investigated in slices of guinea-pig cerebral cortex, kept at rest or electrically stimulated. GABA 1 X 10(-4) - 1 X 10(-3) M raised the cAMP basal levels, bud reduced its increase due to electrical stimulation. These effects were antagonized by picrotoxin 1.6 X 10(-5) M. On the contrary, endogenous GABA did not influence cAMP and cGMP content. In fact, neither ethanolamine-O-sulphate 2 X 10(-3) M nor picrotoxin 1.6 X 10(-5) M affected the normal nucleotide values at all. Higher picrotoxin concentrations (3.2 - 8 X 10(-5) M), however, increased both cyclic nucleotides. Phentolamine counteracted the actions of both GABA 1 X 10(-4) M and picrotoxin 8 X 10(-5) M: therefore, the observed increase in cyclic nucleotides were due to norepinephrine release. Tetrodotoxin antagonized GABA but not picrotoxin metabolic effects. Thus it is suggested that the exogenous amino acid released norepinephrine through a sodium-dependent process, while picrotoxin released the monoamine directly from its storage sites. Clearly, attention must be paid when putative transmitters or their antagonists are added at high concentrations to isolated tissue to study the effect of endogenous compounds.
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Tonini M, Onori L, Lecchini S, Frigo GM, Perucca E, Saltarelli P, Crema A. 5-HT mediated GABA excitatory responses in the guinea-pig proximal ileum. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 1983; 324:180-4. [PMID: 6656890 DOI: 10.1007/bf00503891] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
GABA (3--100 microM) and 5-HT (0.03--30 microM) caused concentration-dependent transient contractions of the longitudinal muscle of the guinea-pig ileum. The contractile response to GABA was antagonized by hyoscine (2.2 microM). TTX (0.7 microM), bicuculline (3 microM), furosemide (25 microM) and desensitization to GABA itself, while hexamethonium (20 microM) and methysergide (20 microM) were without effect. The contractile response to 5-HT was antagonized by hyoscine (2.2 microM), TTX (0.7 microM) and desensitization to 5-HT itself and was unaffected by bicuculline (10 microM), hexamethonium (20 microM), furosemide (25 microM) and methysergide (20 microM). A desensitization procedure that caused a 84.7-fold increase in the 5-HT EC50 also resulted in a 74.1-fold increase of the GABA EC50. Desensitization to GABA caused a reduction of 5-HT induced response but only in preparations desensitized by high (50 microM) concentrations of GABA. The results indicate that GABA-induced contractions in the guinea-pig ileum are mediated by activation of cholinergic motor neurones. This effect appears to be mediated by interneuronal release of 5-HT rather than by a direct stimulatory action of GABA on the effector neurones.
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Tanganelli S, Bianchi C, Beani L. Diazepam antagonizes GABA- and muscimol-induced changes of acetylcholine release in slices of guinea-pig cerebral cortex. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 1983; 324:34-7. [PMID: 6415489 DOI: 10.1007/bf00647835] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The acetylcholine (ACh) release was studied in superfused, electrically-stimulated slices of guinea-pig cerebral cortex. Muscimol and 4,5,6,7-tetrahydroisoxazolo (5-4-c)-pyridin-3-ol (THIP), as well as exogenous GABA, reduced the electrically-evoked ACh release and enhanced its spontaneous outflow. Picrotoxin antagonized these effects. In addition, picrotoxin and ethanolamine-O-sulphate (EOS) caused opposite changes in transmitter outflow, suggesting the existence of an exogenous GABAergic control on the cholinergic nerve endings. Neither flurazepam 6.6 X 10(-6)--3.3 X10(-5) mol/l nor diazepam 3.3 X 10(-6)--3.3 X 10(-5) mol/l by themselves affected ACh release. Diazepam prevented GABA-, muscimol- and EOS-induced changes in spontaneous and 1 Hz-evoked outflow. Ro 15-1788 3.3 X 10(*-6) mol/l abolished diazepam antagonism vs exogenous GABA. The ineffectiveness of flurazepam and diazepam on normal release (i.e. the lack of potentiation vs the endogenous GABAergic control) supports the view that "synaptic" GABA receptors acting upon the cholinergic nerve endings are not coupled with Benzodiazepine receptors. The unexpected diazepam antagonism vs exogenous GABA and GABA-like compounds can be explained with an unusual Diazepam negative cooperation with "extrasynaptic" GABA receptors, possibly present on the cholinergic terminals. Thus, the rule of benzodiazepine-GABA synergism does not seem always tenable, at least at certain pre-synaptic sites.
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Beani L, Bianchi C, Siniscalchi A, Tanganelli S. Glycine-induced changes in acetylcholine release from guinea-pig brain slices. Br J Pharmacol 1983; 79:623-8. [PMID: 6652346 PMCID: PMC2044887 DOI: 10.1111/j.1476-5381.1983.tb11038.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
The effect of glycine (Gly) on acetylcholine (ACh) release from superfused, resting or electrically-stimulated slices of guinea-pig caudate nucleus (CN), brain stem (BS) and cerebral cortex (CC) was studied. The amino acid 1 X 10(-4)-6 X 10(-3)mol 1(-1) reduced the electrically-induced release and increased the spontaneous and KCl-evoked transmitter outflow, mostly in CN but also in BS, whereas it was ineffective in CC. Taurine, chosen as a structurally related compound, moderately affected only the spontaneous release in CN. Strychnine 2 X 10(-7) mol 1(-1) was per se ineffective, but prevented most Gly effects. The Gly-induced increase of ACh outflow in resting CN slices, however, could be completely antagonized only by administering strychnine and picrotoxin together. These findings suggest that: (i) the overall pattern of Gly influence on cholinergic function is similar to that previously described for gamma-aminobutyric acid (GABA); (ii) specific receptors seem to be present in BS and, above all, in CN; (iii) a positive cooperation between endogenous GABA and Gly is evident in resting CN slices; (iv) the absence of any apparent endogenous glycinergic control on the cholinergic neurones casts doubt on but does not exclude the existence of glycinergic neurones in CN.
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