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Smejkalova T, Korinek M, Krusek J, Hrcka Krausova B, Candelas Serra M, Hajdukovic D, Kudova E, Chodounska H, Vyklicky L. Endogenous neurosteroids pregnanolone and pregnanolone sulfate potentiate presynaptic glutamate release through distinct mechanisms. Br J Pharmacol 2021; 178:3888-3904. [PMID: 33988248 PMCID: PMC8518729 DOI: 10.1111/bph.15529] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Revised: 03/23/2021] [Accepted: 05/06/2021] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND AND PURPOSE Neurosteroids influence neuronal function and have multiple promising clinical applications. Direct modulation of postsynaptic neurotransmitter receptors by neurosteroids is well characterized, but presynaptic effects remain poorly understood. Here, we report presynaptic glutamate release potentiation by neurosteroids pregnanolone and pregnanolone sulfate and compare their mechanisms of action to phorbol 12,13-dibutyrate (PDBu), a mimic of the second messenger DAG. EXPERIMENTAL APPROACH We use whole-cell patch-clamp electrophysiology and pharmacology in rat hippocampal microisland cultures and total internal reflection fluorescence (TIRF) microscopy in HEK293 cells expressing GFP-tagged vesicle priming protein Munc13-1, to explore the mechanisms of neurosteroid presynaptic modulation. KEY RESULTS Pregnanolone sulfate and pregnanolone potentiate glutamate release downstream of presynaptic Ca2+ influx, resembling the action of a phorbol ester PDBu. PDBu partially occludes the effect of pregnanolone, but not of pregnanolone sulfate. Calphostin C, an inhibitor that disrupts DAG binding to its targets, reduces the effect PDBu and pregnanolone, but not of pregnanolone sulfate, suggesting that pregnanolone might interact with a well-known DAG/phorbol ester target Munc13-1. However, TIRF microscopy experiments found no evidence of pregnanolone-induced membrane translocation of GFP-tagged Munc13-1, suggesting that pregnanolone may regulate Munc13-1 indirectly or interact with other DAG targets. CONCLUSION AND IMPLICATIONS We describe a novel presynaptic effect of neurosteroids pregnanolone and pregnanolone sulfate to potentiate glutamate release downstream of presynaptic Ca2+ influx. The mechanism of action of pregnanolone, but not of pregnanolone sulfate, partly overlaps with that of PDBu. Presynaptic effects of neurosteroids may contribute to their therapeutic potential in the treatment of disorders of the glutamate system.
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Affiliation(s)
- Tereza Smejkalova
- Institute of PhysiologyCzech Academy of SciencesPragueCzech Republic
| | - Miloslav Korinek
- Institute of PhysiologyCzech Academy of SciencesPragueCzech Republic
| | - Jan Krusek
- Institute of PhysiologyCzech Academy of SciencesPragueCzech Republic
| | | | | | | | - Eva Kudova
- Institute of Organic Chemistry and BiochemistryCzech Academy of SciencesPragueCzech Republic
| | - Hana Chodounska
- Institute of Organic Chemistry and BiochemistryCzech Academy of SciencesPragueCzech Republic
| | - Ladislav Vyklicky
- Institute of PhysiologyCzech Academy of SciencesPragueCzech Republic
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MacKenzie G, Maguire J. The role of ovarian hormone-derived neurosteroids on the regulation of GABAA receptors in affective disorders. Psychopharmacology (Berl) 2014; 231:3333-42. [PMID: 24402140 PMCID: PMC4090295 DOI: 10.1007/s00213-013-3423-z] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Accepted: 12/17/2013] [Indexed: 11/27/2022]
Abstract
RATIONALE Neuroactive derivatives of steroid hormones, neurosteroids, can act on GABAA receptors (GABAARs) to potentiate the effects of GABA on these receptors. Neurosteroids become elevated to physiologically relevant levels under conditions characterized by increased steroid hormones. There is considerable evidence for plasticity of GABAARs associated with altered levels of neurosteroids which may counteract the fluctuations in the levels of these allosteric modulators. OBJECTIVES The objective of this review is to summarize the current literature on GABAAR plasticity under conditions characterized by alterations in neurosteroid levels, such as over the estrous cycle, during puberty, and throughout pregnancy and the postpartum period. RESULTS The expression of specific GABAAR subunits is altered over the estrous cycle, at puberty, and throughout pregnancy and the postpartum period. Inability to regulate δ subunit-containing GABAARs throughout pregnancy and the postpartum period is associated with depression-like behavior restricted to the postpartum period. CONCLUSIONS GABAAR plasticity associated with alterations in neurosteroid levels represents a homeostatic compensatory mechanism to maintain an ideal level of inhibition to offset the potentiating effects of neurosteroids on GABAergic inhibition. Failure to properly regulate GABAARs under conditions of altered neurosteroid levels may increase vulnerability to mood disorders, such as premenstrual syndrome (PMS), premenstrual dysphoric disorder (PMDD), and postpartum depression.
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Affiliation(s)
- Georgina MacKenzie
- Tufts University School of Medicine, Department of Neuroscience, Boston, MA 02111
| | - Jamie Maguire
- Tufts University School of Medicine, Department of Neuroscience, Boston, MA 02111
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Sani G, Kotzalidis GD, Panaccione I, Simonetti A, De Chiara L, Del Casale A, Ambrosi E, Napoletano F, Janiri D, Danese E, Girardi N, Rapinesi C, Serata D, Manfredi G, Koukopoulos AE, Angeletti G, Nicoletti F, Girardi P. Low-dose acetazolamide in the treatment of premenstrual dysphoric disorder: a case series. Psychiatry Investig 2014; 11:95-101. [PMID: 24605130 PMCID: PMC3942558 DOI: 10.4306/pi.2014.11.1.95] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Revised: 03/18/2013] [Accepted: 03/20/2013] [Indexed: 12/31/2022] Open
Abstract
The treatment of premenstrual dysphoric disorder (PMDD) is far from satisfactory, as there is a high proportion of patients who do not respond to conventional treatment. The antidiuretic sulfonamide, acetazolamide, inhibits carbonic anhydrase and potentiates GABAergic transmission; the latter is putatively involved in PMDD. We therefore tried acetazolamide in a series of women with intractable PMDD. Here, we describe a series of eight women diagnosed with DSM-IV-TR PMDD, five of whom had comorbidity with a mood disorder and one with an anxiety disorder, who were resistant to treatment and responded with symptom disappearance after being added-on 125 mg/day acetazolamide for 7-10 days prior to menses each month. Patients were free from premenstrual symptoms at the 12-month follow-up. We suggest that acetazolamide may be used to improve symptoms of PMDD in cases not responding to other treatments. GABAergic mechanisms may be involved in counteracting PMDD symptoms.
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Affiliation(s)
- Gabriele Sani
- NESMOS Department (Neuroscience, Mental Health, and Sensory Organs), Sapienza University, School of Medicine and Psychology, Sant'Andrea Hospital, Rome, Italy
- Centro Lucio Bini, Rome, Italy
| | - Georgios D. Kotzalidis
- NESMOS Department (Neuroscience, Mental Health, and Sensory Organs), Sapienza University, School of Medicine and Psychology, Sant'Andrea Hospital, Rome, Italy
| | - Isabella Panaccione
- NESMOS Department (Neuroscience, Mental Health, and Sensory Organs), Sapienza University, School of Medicine and Psychology, Sant'Andrea Hospital, Rome, Italy
- IRCSS NEUROMED, Pozzilli, Isernia, Italy
| | - Alessio Simonetti
- NESMOS Department (Neuroscience, Mental Health, and Sensory Organs), Sapienza University, School of Medicine and Psychology, Sant'Andrea Hospital, Rome, Italy
- Centro Lucio Bini, Rome, Italy
| | - Lavinia De Chiara
- NESMOS Department (Neuroscience, Mental Health, and Sensory Organs), Sapienza University, School of Medicine and Psychology, Sant'Andrea Hospital, Rome, Italy
- Centro Lucio Bini, Rome, Italy
| | - Antonio Del Casale
- NESMOS Department (Neuroscience, Mental Health, and Sensory Organs), Sapienza University, School of Medicine and Psychology, Sant'Andrea Hospital, Rome, Italy
| | - Elisa Ambrosi
- NESMOS Department (Neuroscience, Mental Health, and Sensory Organs), Sapienza University, School of Medicine and Psychology, Sant'Andrea Hospital, Rome, Italy
| | - Flavia Napoletano
- NESMOS Department (Neuroscience, Mental Health, and Sensory Organs), Sapienza University, School of Medicine and Psychology, Sant'Andrea Hospital, Rome, Italy
- Centro Lucio Bini, Rome, Italy
| | - Delfina Janiri
- NESMOS Department (Neuroscience, Mental Health, and Sensory Organs), Sapienza University, School of Medicine and Psychology, Sant'Andrea Hospital, Rome, Italy
| | - Emanuela Danese
- NESMOS Department (Neuroscience, Mental Health, and Sensory Organs), Sapienza University, School of Medicine and Psychology, Sant'Andrea Hospital, Rome, Italy
| | - Nicoletta Girardi
- NESMOS Department (Neuroscience, Mental Health, and Sensory Organs), Sapienza University, School of Medicine and Psychology, Sant'Andrea Hospital, Rome, Italy
| | - Chiara Rapinesi
- NESMOS Department (Neuroscience, Mental Health, and Sensory Organs), Sapienza University, School of Medicine and Psychology, Sant'Andrea Hospital, Rome, Italy
| | - Daniele Serata
- NESMOS Department (Neuroscience, Mental Health, and Sensory Organs), Sapienza University, School of Medicine and Psychology, Sant'Andrea Hospital, Rome, Italy
| | - Giovanni Manfredi
- NESMOS Department (Neuroscience, Mental Health, and Sensory Organs), Sapienza University, School of Medicine and Psychology, Sant'Andrea Hospital, Rome, Italy
- Centro Lucio Bini, Rome, Italy
| | - Alexia E. Koukopoulos
- NESMOS Department (Neuroscience, Mental Health, and Sensory Organs), Sapienza University, School of Medicine and Psychology, Sant'Andrea Hospital, Rome, Italy
- Centro Lucio Bini, Rome, Italy
| | - Gloria Angeletti
- NESMOS Department (Neuroscience, Mental Health, and Sensory Organs), Sapienza University, School of Medicine and Psychology, Sant'Andrea Hospital, Rome, Italy
- Centro Lucio Bini, Rome, Italy
| | - Ferdinando Nicoletti
- IRCSS NEUROMED, Pozzilli, Isernia, Italy
- Department of Physiology and Pharmacology "Vittorio Erspamer", Sapienza University, School of Medicine and Psychology, Rome, Italy
| | - Paolo Girardi
- NESMOS Department (Neuroscience, Mental Health, and Sensory Organs), Sapienza University, School of Medicine and Psychology, Sant'Andrea Hospital, Rome, Italy
- Centro Lucio Bini, Rome, Italy
- Clinica Neuropsichiatrica Villa Rosa, Suore Ospedaliere del Sacro Cuore di Gesù, Viterbo, Italy
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Wakita M, Kotani N, Kogure K, Akaike N. Inhibition of excitatory synaptic transmission in hippocampal neurons by levetiracetam involves Zn²⁺-dependent GABA type A receptor-mediated presynaptic modulation. J Pharmacol Exp Ther 2013; 348:246-59. [PMID: 24259680 DOI: 10.1124/jpet.113.208751] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Levetiracetam (LEV) is an antiepileptic drug with a unique but as yet not fully resolved mechanism of action. Therefore, by use of a simplified rat-isolated nerve-bouton preparation, we have investigated how LEV modulates glutamatergic transmission from mossy fiber terminals to hippocampal CA3 neurons. Action potential-evoked excitatory postsynaptic currents (eEPSCs) were recorded using a conventional whole-cell patch-clamp recording configuration in voltage-clamp mode. The antiepileptic drug phenytoin decreased glutamatergic eEPSCs in a concentration-dependent fashion by inhibiting voltage-dependent Na⁺ and Ca²⁺ channel currents. In contrast, LEV had no effect on eEPSCs or voltage-dependent Na⁺ or Ca²⁺ channel currents. Activation of presynaptic GABA type A (GABA(A)) receptors by muscimol induced presynaptic inhibition of eEPSCs, resulting from depolarization block. Low concentrations of Zn²⁺, which had no effect on eEPSCs, voltage-dependent Na⁺ or Ca²⁺ channel currents, or glutamate receptor-mediated whole cell currents, reduced the muscimol-induced presynaptic inhibition. LEV applied in the continuous presence of 1 µM muscimol and 1 µM Zn²⁺ reversed this Zn²⁺ modulation on eEPSCs. The antagonizing effect of LEV on Zn²⁺-induced presynaptic GABA(A) receptor inhibition was also observed with the Zn²⁺ chelators Ca-EDTA and RhodZin-3. Our results clearly show that LEV removes the Zn²⁺-induced suppression of GABA(A)-mediated presynaptic inhibition, resulting in a presynaptic decrease in glutamate-mediated excitatory transmission. Our results provide a novel mechanism by which LEV may inhibit neuronal activity.
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Affiliation(s)
- Masahito Wakita
- Research Division for Clinical Pharmacology, Medical Corporation, Jyuryokai, Kumamoto Kinoh Hospital, Kumamoto, Japan (M.W., N.A.); Research Division for Life Science, Kumamoto Health Science University, Kumamoto, Japan (M.W., N.A.); Research Division of Neurophysiology, Kitamoto Hospital, Koshigaya, Japan (N.K., N.A); and Kogure Medical Clinic, Chouseikai Medical Corporation, Fukaya City, Saitama, Japan (K.K.)
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Carver CM, Reddy DS. Neurosteroid interactions with synaptic and extrasynaptic GABA(A) receptors: regulation of subunit plasticity, phasic and tonic inhibition, and neuronal network excitability. Psychopharmacology (Berl) 2013; 230:151-88. [PMID: 24071826 PMCID: PMC3832254 DOI: 10.1007/s00213-013-3276-5] [Citation(s) in RCA: 171] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Accepted: 08/29/2013] [Indexed: 12/25/2022]
Abstract
RATIONALE Neurosteroids are steroids synthesized within the brain with rapid effects on neuronal excitability. Allopregnanolone, allotetrahydrodeoxycorticosterone, and androstanediol are three widely explored prototype endogenous neurosteroids. They have very different targets and functions compared to conventional steroid hormones. Neuronal γ-aminobutyric acid (GABA) type A (GABA(A)) receptors are one of the prime molecular targets of neurosteroids. OBJECTIVE This review provides a critical appraisal of recent advances in the pharmacology of endogenous neurosteroids that interact with GABA(A) receptors in the brain. Neurosteroids possess distinct, characteristic effects on the membrane potential and current conductance of the neuron, mainly via potentiation of GABA(A) receptors at low concentrations and direct activation of receptor chloride channel at higher concentrations. The GABA(A) receptor mediates two types of inhibition, now characterized as synaptic (phasic) and extrasynaptic (tonic) inhibition. Synaptic release of GABA results in the activation of low-affinity γ2-containing synaptic receptors, while high-affinity δ-containing extrasynaptic receptors are persistently activated by the ambient GABA present in the extracellular fluid. Neurosteroids are potent positive allosteric modulators of synaptic and extrasynaptic GABA(A) receptors and therefore enhance both phasic and tonic inhibition. Tonic inhibition is specifically more sensitive to neurosteroids. The resulting tonic conductance generates a form of shunting inhibition that controls neuronal network excitability, seizure susceptibility, and behavior. CONCLUSION The growing understanding of the mechanisms of neurosteroid regulation of the structure and function of the synaptic and extrasynaptic GABA(A) receptors provides many opportunities to create improved therapies for sleep, anxiety, stress, epilepsy, and other neuropsychiatric conditions.
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Affiliation(s)
- Chase Matthew Carver
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University Health Science Center, 2008 Medical Research and Education Building, 8447 State Highway 47, Bryan, TX, 77807-3260, USA
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Borges K. Slc10A4 - what do we know about the function of this "secret ligand carrier" protein? Exp Neurol 2013; 248:258-61. [PMID: 23810836 DOI: 10.1016/j.expneurol.2013.06.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Revised: 06/13/2013] [Accepted: 06/15/2013] [Indexed: 12/27/2022]
Abstract
This commentary discusses the possible functions of a relatively newly described solute carrier protein, Slc10a4, in regards to a recent article by Zelano et al. (2013) published in the January issue of Experimental Neurology, 239, 73-81. Slc10a4 belongs to the sodium-bile acid cotransporter family (Slc10), but does not show plasma membrane transport activity of bile acids and related molecules. It is co-localized with synaptic vesicle transporters for acetylcholine and dopamine. In Slc10a4 lacking mice, Zelano et al. found increased excitability in hippocampal slices and in vivo responses to pilocarpine, but not kainate. These findings are critically examined here. This author speculates on the possible function of Slc10a4, but remains partial about "specific effects of Slc10a4 in cholinergic systems". It is hoped that approaches targeting human SLC10A4 can be discovered for potential clinical use in neurological disorders, such as Alzheimer's and Parkinson's disease, schizophrenia and addiction. Conversely, some side effects are expected due to peripheral Slc10a4 localization in sympathetic and parasympathetic nerves, as well as mast cells.
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Affiliation(s)
- Karin Borges
- Department of Pharmacology, School of Biomedical Sciences, The University of Queensland, Skerman Building 65, St Lucia QLD 4072, Australia.
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Pregnenolone sulfate modulates glycinergic transmission in rat medullary dorsal horn neurons. Eur J Pharmacol 2013; 712:30-8. [PMID: 23665111 DOI: 10.1016/j.ejphar.2013.04.039] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Revised: 04/19/2013] [Accepted: 04/26/2013] [Indexed: 11/20/2022]
Abstract
The neurosteroid pregnenolone sulfate (PS), a representative excitatory neuromodulator, has a variety of neuropharmacological actions, such as memory enhancement and convulsant effects. In this study, the effects of PS on glycinergic transmission, such as glycinergic spontaneous miniature inhibitory postsynaptic currents (mIPSCs), were investigated in acutely isolated medullary dorsal horn neurons by use of a conventional whole-cell patch-clamp technique. PS significantly increased the frequency but decreased the amplitude of glycinergic mIPSCs in a concentration-dependent manner. PS also accelerated the decay time constant of glycinergic mIPSCs. The PS-induced decrease in mIPSC amplitude was due to the direct postsynaptic inhibition of glycine receptors because PS inhibited the glycine-induced Cl(-) currents in a noncompetitive manner. The PS-induced increase in mIPSC frequency was not due to the activation of α7 nicotinic acetylcholine, NMDA, σ1 receptors and voltage-dependent Ca(2+) channels, which are known to be molecular targets of PS. On the other hand, the PS-induced increase in mIPSC frequency was completely attenuated either in the Ca(2+)-free external solution or in the presence of transient receptor potential (TRP) channel blockers, suggesting that PS elicits an increase in Ca(2+) concentration within glycinergic nerve terminals via the activation of putative TRP channels. The PS-mediated modulation of glycinergic synaptic transmission, such as the enhancement of presynaptic glycine release and direct inhibition of postsynaptic glycine receptors, might have a broad impact on the excitability of medullary dorsal horn neurons and therefore affect the processing of nociceptive transmission from orofacial tissues.
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Puia G, Gullo F, Dossi E, Lecchi M, Wanke E. Novel modulatory effects of neurosteroids and benzodiazepines on excitatory and inhibitory neurons excitability: a multi-electrode array recording study. Front Neural Circuits 2012; 6:94. [PMID: 23233835 PMCID: PMC3516127 DOI: 10.3389/fncir.2012.00094] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2012] [Accepted: 11/08/2012] [Indexed: 01/26/2023] Open
Abstract
The balance between glutamate- and GABA-mediated neurotransmission in the brain is fundamental in the nervous system, but it is regulated by the “tonic” release of a variety of endogenous factors. One such important group of molecules are the neurosteroids (NSs) which, similarly to benzodiazepines (BDZs), enhance GABAergic neurotransmission. The purpose of our work was to investigate, at in vivo physiologically relevant concentrations, the effects of NSs and BDZs as GABA modulators on dissociated neocortical neuron networks grown in long-term culture. We used a multi-electrode array (MEA) recording technique and a novel analysis that was able to both identify the action potentials of engaged excitatory and inhibitory neurons and to detect drug-induced network up-states (burst). We found that the NSs tetrahydrodeoxycorticosterone (THDOC) and allopregnanolone (ALLO) applied at low nanomolar concentrations, produced different modulatory effects on the two neuronal clusters. Conversely, at high concentrations (1 μM), both NSs, decreased excitatory and inhibitory neuron cluster excitability; however, even several hours after wash-out, the excitability of inhibitory neurons continued to be depressed, leading to a network long-term depression (LTD). The BDZs clonazepam (CLZ) and midazolam (MDZ) also decreased the network excitability, but only MDZ caused LTD of inhibitory neuron cluster. To investigate the origin of the LTD after MDZ application, we tested finasteride (FIN), an inhibitor of endogenous NSs synthesis. FIN did not prevent the LTD induced by MDZ, but surprisingly induced it after application of CLZ. The significance and possible mechanisms underlying these LTD effects of NSs and BDZs are discussed. Taken together, our results not only demonstrate that ex vivo networks show a sensitivity to NSs and BDZs comparable to that expressed in vivo, but also provide a new global in vitro description that can help in understanding their activity in more complex systems.
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Affiliation(s)
- Giulia Puia
- Department of Biomedical Sciences, University of Modena and Reggio Emilia Modena, Italy
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