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1.
J Neurochem ; 168(3): 238-250, 2024 03.
Artículo en Inglés | MEDLINE | ID: mdl-38332572

RESUMEN

Deciphering the molecular pathways associated with N-methyl-D-aspartate receptor (NMDAr) hypofunction and its interaction with antipsychotics is necessary to advance our understanding of the basis of schizophrenia, as well as our capacity to treat this disease. In this regard, the development of human brain-derived models that are amenable to studying the neurobiology of schizophrenia may contribute to filling the gaps left by the widely employed animal models. Here, we assessed the proteomic changes induced by the NMDA glutamate receptor antagonist MK-801 on human brain slice cultures obtained from adult donors submitted to respective neurosurgery. Initially, we demonstrated that MK-801 diminishes NMDA glutamate receptor signaling in human brain slices in culture. Next, using mass-spectrometry-based proteomics and systems biology in silico analyses, we found that MK-801 led to alterations in proteins related to several pathways previously associated with schizophrenia pathophysiology, including ephrin, opioid, melatonin, sirtuin signaling, interleukin 8, endocannabinoid, and synaptic vesicle cycle. We also evaluated the impact of both typical and atypical antipsychotics on MK-801-induced proteome changes. Interestingly, the atypical antipsychotic clozapine showed a more significant capacity to counteract the protein alterations induced by NMDAr hypofunction than haloperidol. Finally, using our dataset, we identified potential modulators of the MK-801-induced proteome changes, which may be considered promising targets to treat NMDAr hypofunction in schizophrenia. This dataset is publicly available and may be helpful in further studies aimed at evaluating the effects of MK-801 and antipsychotics in the human brain.


Asunto(s)
Antipsicóticos , Clozapina , Animales , Humanos , Clozapina/farmacología , Haloperidol/farmacología , Antagonistas de Aminoácidos Excitadores/farmacología , Maleato de Dizocilpina/farmacología , Proteoma/metabolismo , N-Metilaspartato , Ácido Glutámico/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , Proteómica , Antipsicóticos/farmacología , Encéfalo/metabolismo
2.
Neuropsychopharmacology ; 49(6): 905-914, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38177696

RESUMEN

The NMDA receptor (NMDAR) antagonist ketamine has shown great potential as a rapid-acting antidepressant; however, its use is limited by poor oral bioavailability and a side effect profile that necessitates in-clinic dosing. GM-1020 is a novel NMDAR antagonist that was developed to address these limitations of ketamine as a treatment for depression. Here, we present the preclinical characterization of GM-1020 alongside ketamine, for comparison. In vitro, we profiled GM-1020 for binding to NMDAR and functional inhibition using patch-clamp electrophysiology. In vivo, GM-1020 was assessed for antidepressant-like efficacy using the Forced Swim Test (FST) and Chronic Mild Stress (CMS), while motor side effects were assessed in spontaneous locomotor activity and on the rotarod. The pharmacokinetic properties of GM-1020 were profiled across multiple preclinical species. Electroencephalography (EEG) was performed to determine indirect target engagement and provide a potentially translational biomarker. These results demonstrate that GM-1020 is an orally bioavailable NMDAR antagonist with antidepressant-like efficacy at exposures that do not produce unwanted motor effects.


Asunto(s)
Antidepresivos , Receptores de N-Metil-D-Aspartato , Animales , Antidepresivos/administración & dosificación , Antidepresivos/farmacología , Antidepresivos/farmacocinética , Receptores de N-Metil-D-Aspartato/antagonistas & inhibidores , Masculino , Ratas , Ratones , Administración Oral , Ratas Sprague-Dawley , Disponibilidad Biológica , Ketamina/administración & dosificación , Ketamina/farmacología , Depresión/tratamiento farmacológico , Actividad Motora/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Ratones Endogámicos C57BL , Antagonistas de Aminoácidos Excitadores/administración & dosificación , Antagonistas de Aminoácidos Excitadores/farmacología , Antagonistas de Aminoácidos Excitadores/farmacocinética , Humanos
3.
Radiat Oncol ; 19(1): 16, 2024 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-38291439

RESUMEN

BACKGROUND: Ionotropic glutamate receptors α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor (AMPAR) and N-methyl-D-aspartate receptor (NMDAR) modulate proliferation, invasion and radioresistance in glioblastoma (GB). Pharmacological targeting is difficult as many in vitro-effective agents are not suitable for in patient applications. We aimed to develop a method to test the well tolerated AMPAR- and NMDAR-antagonist xenon gas as a radiosensitizer in GB. METHODS: We designed a diffusion-based system to perform the colony formation assay (CFA), the radiobiological gold standard, under xenon exposure. Stable and reproducible gas atmosphere was validated with oxygen and carbon dioxide as tracer gases. After checking for AMPAR and NMDAR expression via immunofluorescence staining we performed the CFA with the glioblastoma cell lines U87 and U251 as well as the non-glioblastoma derived cell line HeLa. Xenon was applied after irradiation and additionally tested in combination with NMDAR antagonist memantine. RESULTS: The gas exposure system proved compatible with the CFA and resulted in a stable atmosphere of 50% xenon. Indications for the presence of glutamate receptor subunits were present in glioblastoma-derived and HeLa cells. Significantly reduced clonogenic survival by xenon was shown in U87 and U251 at irradiation doses of 4-8 Gy and 2, 6 and 8 Gy, respectively (p < 0.05). Clonogenic survival was further reduced by the addition of memantine, showing a significant effect at 2-8 Gy for both glioblastoma cell lines (p < 0.05). Xenon did not significantly reduce the surviving fraction of HeLa cells until a radiation dose of 8 Gy. CONCLUSION: The developed system allows for testing of gaseous agents with CFA. As a proof of concept, we have, for the first time, unveiled indications of radiosensitizing properties of xenon gas in glioblastoma.


Asunto(s)
Glioblastoma , Fármacos Sensibilizantes a Radiaciones , Humanos , Xenón/farmacología , Xenón/metabolismo , Antagonistas de Aminoácidos Excitadores/farmacología , Glioblastoma/radioterapia , Glioblastoma/metabolismo , Memantina , Células HeLa , Receptores de N-Metil-D-Aspartato , Fármacos Sensibilizantes a Radiaciones/farmacología
4.
eNeuro ; 11(2)2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38176904

RESUMEN

NMDA receptors (NMDARs) modulate glutamatergic excitatory tone in the brain via two complementary modalities: a phasic excitatory postsynaptic current and a tonic extrasynaptic modality. Here, we demonstrated that the tonic NMDAR-current (I NMDA) mediated by NR2A-containing NMDARs is an efficient biosensor detecting the altered ambient glutamate level in the supraoptic nucleus (SON). I NMDA of magnocellular neurosecretory cells (MNCs) measured by nonselective NMDARs antagonist, AP5, at holding potential (V holding) -70 mV in low concentration of ECF Mg2+ ([Mg2+]o) was transiently but significantly increased 1-week post induction of a DOCA salt hypertensive model rat which was compatible with that induced by a NR2A-selective antagonist, PEAQX (I PEAQX) in both DOCA-H2O and DOCA-salt groups. In agreement, NR2B antagonist, ifenprodil, or NR2C/D antagonist, PPDA, did not affect the holding current (I holding) at V holding -70 mV. Increased ambient glutamate by exogenous glutamate (10 mM) or excitatory amino acid transporters (EAATs) antagonist (TBOA, 50 mM) abolished the I PEAQX difference between two groups, suggesting that attenuated EAATs activity increased ambient glutamate concentration, leading to the larger I PEAQX in DOCA-salt rats. In contrast, only ifenprodil but not PEAQX and PPDA uncovered I NMDA at V holding +40 mV under 1.2 mM [Mg2+]o condition. I ifenprodil was not different in DOCA-H2O and DOCA-salt groups. Finally, NR2A, NR2B, and NR2D protein expression were not different in the SON of the two groups. Taken together, NR2A-containing NMDARs efficiently detected the increased ambient glutamate concentration in the SON of DOCA-salt hypertensive rats due to attenuated EAATs activity.


Asunto(s)
Acetato de Desoxicorticosterona , Receptores de N-Metil-D-Aspartato , Ratas , Animales , Receptores de N-Metil-D-Aspartato/metabolismo , N-Metilaspartato/metabolismo , N-Metilaspartato/farmacología , Ácido Glutámico/metabolismo , Núcleo Supraóptico/metabolismo , Antagonistas de Aminoácidos Excitadores/farmacología
5.
Pharmacol Biochem Behav ; 234: 173678, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37979731

RESUMEN

Multiple interacting neural systems are involved in sustaining nicotine reinforcement. We and others have shown that dopamine D1 receptors and glutamate NMDA receptors both play important roles in nicotine reinforcement. Blockade of D1 receptors with the antagonist SCH-23390 (0.02 mg/kg) both acutely and chronically significantly decreased nicotine self-administration in rats. Blockade of NMDA receptors (10 mg/kg) acutely with memantine significantly increased nicotine self-administration, but chronic blockade of NMDA receptors with memantine significantly decreased nicotine self-administration. The current study examined the interactions of acute and chronic administration of SCH-23390 and memantine on nicotine self-administration in female rats. Replicating earlier studies, acute and chronic SCH-23390 significantly decreased nicotine self-administration and memantine had a biphasic effect with acute administration increasing nicotine self-administration and chronic memantine showed a non-significant trend toward decreasing it. However, chronic interaction study showed that memantine significantly attenuated the decrease in nicotine self-administration caused by chronic SCH-23390. These studies provide important information that memantine attenuates the efficacy of D1 antagonist SCH 23390 in reducing nicotine-self-administration. These two drugs do not appear to have mutually potentiating effects to aid tobacco cessation.


Asunto(s)
Antagonistas de Dopamina , Nicotina , Ratas , Femenino , Animales , Nicotina/farmacología , Antagonistas de Dopamina/farmacología , Antagonistas de Aminoácidos Excitadores/farmacología , Dopamina , N-Metilaspartato , Memantina/farmacología , Receptores de N-Metil-D-Aspartato , Ratas Sprague-Dawley , Receptores de Dopamina D1/metabolismo , Benzazepinas/farmacología
6.
Neurosci Lett ; 820: 137595, 2024 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-38096972

RESUMEN

The current study was designed to examine the role of glutamate NMDA receptors of the mediodorsal thalamus (MD) in scopolamine-induced memory impairment. Adult male rats were bilaterally cannulated into the MD. According to the results, intraperitoneal (i.p.) administration of scopolamine (1.5 mg/kg) immediately after the training phase (post-training) impaired memory consolidation. Bilateral microinjection of the glutamate NMDA receptors agonist, N-Methyl-D-aspartic acid (NMDA; 0.05 µg/rat), into the MD significantly improved scopolamine-induced memory consolidation impairment. Co-administration of D-AP5, a glutamate NMDA receptor antagonist (0.001-0.005 µg/rat, intra-MD) potentiated the response of an ineffective dose of scopolamine (0.5 mg/kg, i.p.) to impair memory consolidation, mimicking the response of a higher dose of scopolamine. Noteworthy, post-training intra-MD microinjections of the same doses of NMDA or D-AP5 alone had no effect on memory consolidation. Moreover, the blockade of the glutamate NMDA receptors by 0.003 ng/rat of D-AP5 prevented the improving effect of NMDA on scopolamine-induced amnesia. Thus, it can be concluded that the MD glutamatergic system may be involved in scopolamine-induced memory impairment via the NMDA receptor signaling pathway.


Asunto(s)
N-Metilaspartato , Escopolamina , Ratas , Masculino , Animales , Escopolamina/farmacología , N-Metilaspartato/farmacología , Receptores de N-Metil-D-Aspartato/metabolismo , Ácido Glutámico/metabolismo , Ratas Wistar , Amnesia/inducido químicamente , Trastornos de la Memoria/inducido químicamente , Agonistas de Aminoácidos Excitadores/farmacología , Antagonistas de Aminoácidos Excitadores/farmacología , Tálamo/metabolismo , Reacción de Prevención
7.
Sci Adv ; 9(49): eadj6187, 2023 Dec 08.
Artículo en Inglés | MEDLINE | ID: mdl-38064562

RESUMEN

While most research and treatments for multiple sclerosis (MS) focus on autoimmune reactions causing demyelination, it is possible that neurodegeneration precedes the autoimmune response. Hence, glutamate receptor antagonists preventing excitotoxicity showed promise in MS animal models, though blocking glutamate signaling prevents critical neuronal functions. This study reports the discovery of a small molecule that prevents AMPA-mediated excitotoxicity by targeting an allosteric binding site. A machine learning approach was used to screen for small molecules targeting the AMPA receptor GluA2 subunit. The lead candidate has potent effects in restoring neurological function and myelination while reducing the immune response in experimental autoimmune encephalitis and cuprizone MS mouse models without affecting basal neurotransmission or learning and memory. These findings facilitate development of a treatment for MS with a different mechanism of action than current immune modulatory drugs and avoids important off-target effects of glutamate receptor antagonists. This class of MS therapeutics could be useful as an alternative or complementary treatment to existing therapies.


Asunto(s)
Esclerosis Múltiple , Ratones , Animales , Ácido alfa-Amino-3-hidroxi-5-metil-4-isoxazol Propiónico/farmacología , Antagonistas de Aminoácidos Excitadores/farmacología , Receptores AMPA , Neuronas/metabolismo
8.
eNeuro ; 10(11)2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37940562

RESUMEN

Psychotic drugs such as ketamine induce symptoms close to schizophrenia and stimulate the production of γ oscillations, as also seen in patients, but the underlying mechanisms are still unclear. Here, we have used computational models of cortical networks generating γ oscillations, and have integrated the action of drugs such as ketamine to partially block NMDA receptors (NMDARs). The model can reproduce the paradoxical increase of γ oscillations by NMDA receptor antagonists, assuming that antagonists affect NMDA receptors with higher affinity on inhibitory interneurons. We next used the model to compare the responsiveness of the network to external stimuli, and found that when NMDA channels are blocked, an increase of γ power is observed altogether with an increase of network responsiveness. However, this responsiveness increase applies not only to γ states, but also to asynchronous states with no apparent γ. We conclude that NMDA antagonists induce an increased excitability state, which may or may not produce γ oscillations, but the response to external inputs is exacerbated, which may explain phenomena such as altered perception or hallucinations.


Asunto(s)
Ketamina , Receptores de N-Metil-D-Aspartato , Humanos , Receptores de N-Metil-D-Aspartato/metabolismo , Ketamina/farmacología , Antagonistas de Aminoácidos Excitadores/farmacología , N-Metilaspartato , Corteza Cerebral/metabolismo
9.
Bull Exp Biol Med ; 175(4): 446-449, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37768458

RESUMEN

The non-competitive NMDA glutamate receptor antagonist memantine has neuroprotective properties and is the first non-cholinergic drug approved for the treatment of Alzheimer's disease. The purpose of this work was to test the hypothesis that injections of memantine to healthy animals can affect the subunit composition of NMDA receptors in the brain, which may explain the effects of its chronic administration. For this, the expression of subunits GluN1, GluN2A, GluN2B, and GluN2C was studied in the hippocampus and prefrontal cortex of rats after single or five subchronic injections of memantine. The results showed that the GluN2C subunit (GRIN2C) plays an important role in the effects of memantine; against the background of memantine treatment, the expression of this subunit markedly decreased in the prefrontal cortex, but not in the hippocampus, which significantly affected the excitation/inhibition balance in cortical structures.


Asunto(s)
Enfermedad de Alzheimer , Receptores de N-Metil-D-Aspartato , Ratas , Animales , Receptores de N-Metil-D-Aspartato/metabolismo , Memantina/farmacología , Antagonistas de Aminoácidos Excitadores/farmacología , Encéfalo/metabolismo , Enfermedad de Alzheimer/tratamiento farmacológico
10.
Behav Brain Res ; 450: 114491, 2023 07 26.
Artículo en Inglés | MEDLINE | ID: mdl-37172740

RESUMEN

Sex difference has been reported in several behavioral endophenotypes of neuropsychiatric disorder in both rodents and humans. However, sex difference in cognitive symptoms associated with neuropsychiatric disorders has not been studied in detail. In this study, we induced cognitive impairment using the NMDA receptor antagonist, dizocilpine (MK-801), in male and female C57BL/6 J mice and performed a visual discrimination task in an automated touchscreen system. We found that discrimination performance decreased with increased doses of MK-801 in both sexes. However, female mice showed stronger deficit in discrimination performance than the male mice especially after administration of low (0.01 mg/kg) and high (0.15 mg/kg) doses of MK-801. Furthermore, we tested if administration of orexin A, orexin-1 receptor antagonist SB-334867 or orexin-2 receptor antagonist EMPA rescued MK-801 (0.15 mg/kg) induced cognitive impairment in visual discrimination. We found that nasal administration of orexin A partially rescued the cognitive impairment induced by MK-801 in females but not in males. Taken together, our data show that female C57BL/6 J mice are more sensitive compared to males to some doses of MK-801 in discrimination learning task and that orexin A partially rescues this cognitive impairment in females.


Asunto(s)
Disfunción Cognitiva , Maleato de Dizocilpina , Humanos , Femenino , Ratones , Masculino , Animales , Maleato de Dizocilpina/farmacología , Orexinas/farmacología , Antagonistas de Aminoácidos Excitadores/farmacología , Administración Intranasal , Ratones Endogámicos C57BL , Disfunción Cognitiva/inducido químicamente , Disfunción Cognitiva/tratamiento farmacológico
11.
Int J Mol Sci ; 24(6)2023 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-36982408

RESUMEN

This study aimed to investigate the effects of ketamine, an N-methyl-D-aspartate (NMDA) receptor antagonist, on endoplasmic reticulum (ER) stress in rats with neuropathic pain (NP). NP was induced in rats through ligation and transection of the sciatic nerve. After confirmation of NP, the animals were randomly divided into ketamine and control groups. The ketamine group was administered 50 mg/kg of ketamine at 15, 18, and 21 days after surgery. The expression of NMDA receptor subtype 2B (NR2B) and ER stress markers in the spinal cord (L5) was evaluated. The ipsilateral side of the surgery in the ketamine group was less sensitive to mechanical and cold stimulations. The expression of NR2B on the ipsilateral side was significantly lower in the ketamine group than in the control group (18.93 ± 1.40% vs. 31.08 ± 0.74%, p < 0.05). All markers for ER stress on the ipsilateral side of the surgery in both groups had higher expression than those on the contralateral side. The expression of activating transcription factor-6 (ATF-6) on the ipsilateral side was significantly lower in the ketamine group than in the control group (p < 0.05). Systemic administration of ketamine inhibited the expression of NMDA receptors and improved NP symptoms. Among the markers of ER stress, the therapeutic effect of ketamine is associated with the inhibition of ATF-6 expression.


Asunto(s)
Ketamina , Neuralgia , Ratas , Animales , Ketamina/farmacología , Ketamina/uso terapéutico , Ratas Sprague-Dawley , Antagonistas de Aminoácidos Excitadores/farmacología , Dimensión del Dolor , Neuralgia/tratamiento farmacológico , Neuralgia/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo
12.
Naunyn Schmiedebergs Arch Pharmacol ; 396(7): 1371-1398, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-36869904

RESUMEN

Migraine is a debilitating disorder affecting females more frequently than males. There is some evidence that drugs targeting glutamate receptors: memantine and ketamine might be beneficial in the therapy of this entity. Therefore, the purpose of this work is to present NMDA receptor antagonists, memantine and ketamine, as potential anti-migraine agents. We searched PubMed/MEDLINE, Embase, and clinical trials submitted to ClinicalTrials.gov to find publications describing eligible trials published between database inception and December 31, 2021. This comprehensive literature review summarizes data on the use of the NMDA receptor antagonists memantine and ketamine in the pharmacotherapy of migraine. Results from 20 previous and recent preclinical experiments are discussed and correlated with 19 clinical trials (including case series, open-label, and randomized placebo-controlled trials). For the purposes of this review, the authors hypothesized that the propagation of SD is a major mechanism in the pathophysiology of migraine. In several animal studies and in vitro studies, memantine and ketamine inhibited or reduced propagation of the SD. In addition, the results of clinical trials suggest that memantine or ketamine may be an effective treatment option for migraine. However, most studies on these agents lack control group. Although further clinical trials are needed, the results suggest that ketamine or memantine may be promising molecules for the treatment of severe migraine. Particular attention should be paid to people who have a treatment-resistant form of migraine with aura or have exhausted existing treatment options. For them, the drugs under discussion could represent an interesting alternative in the future.


Asunto(s)
Ketamina , Trastornos Migrañosos , Masculino , Animales , Femenino , Memantina/uso terapéutico , Ketamina/uso terapéutico , Ketamina/farmacología , Antagonistas de Aminoácidos Excitadores/uso terapéutico , Antagonistas de Aminoácidos Excitadores/farmacología , Receptores de N-Metil-D-Aspartato , Trastornos Migrañosos/tratamiento farmacológico
13.
Eur Arch Psychiatry Clin Neurosci ; 273(7): 1463-1476, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36890259

RESUMEN

This review article presents select recent studies that form the basis for the development of esmethadone into a potential new drug. Esmethadone is a promising member of the pharmacological class of uncompetitive N-methyl-D-aspartate receptor (NMDAR) antagonists that have shown efficacy for major depressive disorder (MDD) and other diseases and disorders, such as Alzheimer's dementia and pseudobulbar affect. The other drugs in the novel class of NMDAR antagonists with therapeutic uses that are discussed for comparative purposes in this review are esketamine, ketamine, dextromethorphan, and memantine. We present in silico, in vitro, in vivo, and clinical data for esmethadone and other uncompetitive NMDAR antagonists that may advance our understanding of the role of these receptors in neural plasticity in health and disease. The efficacy of NMDAR antagonists as rapid antidepressants may advance our understanding of the neurobiology of MDD and other neuropsychiatric diseases and disorders.


Asunto(s)
Enfermedad de Alzheimer , Trastorno Depresivo Mayor , Humanos , Antagonistas de Aminoácidos Excitadores/farmacología , Trastorno Depresivo Mayor/tratamiento farmacológico , Memantina/farmacología , Memantina/uso terapéutico , Antidepresivos/farmacología , Antidepresivos/uso terapéutico , Enfermedad de Alzheimer/tratamiento farmacológico
14.
Neuropsychobiology ; 82(2): 91-103, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36731434

RESUMEN

INTRODUCTION: Cognition and emotion are fundamentally integrated in the brain and mutually contribute to behavior. The relation between working memory (WM) and emotion is particularly suited to investigate cognition-emotion interaction since WM is an essential component of many higher cognitive functions. Ketamine affects not only WM but also has a profound impact on emotional processing. Effects of acute ketamine challenge are sensitive to modulation by pretreatment with lamotrigine, which inhibits glutamate release. Accordingly, a combination of these approaches should be particularly suited to investigate cognition-emotion interaction. METHODS: Seventy five healthy subjects were investigated in a double-blind, placebo-controlled, randomized, single-dose, parallel-group study with three treatment conditions. All subjects underwent two scanning sessions (acute/post 24 h). RESULTS: Compared to placebo, acute ketamine administration induced significant dissociative, psychotomimetic, and cognitive effects, as well as an increase in neural activity during WM for positive stimuli. Inhibition of glutamate release by pretreatment with lamotrigine did not influence ketamine's subjective effects, but significantly attenuated its impact on emotional WM and associated neural activity. There was no effect on these measures 24 h after ketamine administration. CONCLUSION: Our results demonstrate differential acute effects of modulated glutamate release and a swift restoration of disturbed neurobehavioral homeostasis in healthy subjects.


Asunto(s)
Ketamina , Humanos , Ketamina/farmacología , Ketamina/uso terapéutico , Lamotrigina/farmacología , Antagonistas de Aminoácidos Excitadores/farmacología , Encéfalo , Emociones/fisiología , Cognición , Anticonvulsivantes/farmacología , Ácido Glutámico
15.
Neurochem Res ; 48(7): 2104-2115, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-36792758

RESUMEN

Nicotinic receptors are present in the retina of different vertebrates, and in the chick retina, it is present during early development throughout to post-hatching. These receptors are activated by nicotine, an alkaloid with addictive and neurotransmitter release modulation properties, such as GABA signaling. Here we evaluated the mechanisms of nicotine signaling in the avian retina during the development of neuron-glia cells at a stage where synapses are peaking. Nicotine almost halved [3H]-GABA uptake, reducing it by 45% whilst increasing more than two-fold [3H]-GABA release in E12 embryonic chick retinas. Additionally, nicotine mediated a 33% increase in [3H]-D-aspartate release. MK-801 50 µM blocked 66% of nicotine-induced [3H]-GABA release and Gö 6983 100 nM prevented the nicotine-induced reduction in [3H]-GABA uptake by rescuing 40% of this neurotransmitter uptake, implicating NMDAR and PKC (respectively) in the nicotinic responses. In addition, NO-711 prevented [3H]-GABA uptake and release induced by nicotine. Furthermore, the relevance of calcium influx for PKC activation was evidenced through fura-2 imaging. We conclude that the shift of GABA transport mediated by nicotine promotes GABA release by inducing transporter reversal via nicotine-induced EAA release through EAATs, or by a direct effect of nicotine in activating nicotinic receptors permeable to calcium and promoting PKC pathway activation and shifting GAT-1 activity, both prompting calcium influx, and activation of the PKC pathway and shifting GAT-1 activity.


Asunto(s)
Nicotina , Receptores Nicotínicos , Animales , Nicotina/farmacología , Receptores de N-Metil-D-Aspartato/metabolismo , Calcio/metabolismo , Ácido gamma-Aminobutírico/metabolismo , Antagonistas de Aminoácidos Excitadores/farmacología , Receptores Nicotínicos/metabolismo , Retina
16.
Neuroscience ; 514: 56-66, 2023 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-36716915

RESUMEN

The lateral habenula (LHb) is an epithalamic brain region viewed as a converging hub, integrating information from a large connectome and then projecting to few critical midbrain monoaminergic systems. Numerous studies have explored the roles of the LHb, notably in aversion and avoidance. An important recurring finding when manipulating the LHb is the induction of anxiety-related behaviours. However, its exact role in such behaviours remains poorly understood. In the present study, we used two pharmacological approaches altering LHb activity, intra-LHb infusion of either the GABA-A receptor agonist, Muscimol, or the glutamatergic AMPA receptor antagonist, 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) and exposed rats to three consecutive open field (OF) sessions. We found that both pharmacological treatments prevented rats to explore the centre of the OF, considered as the most anxiogenic part of the apparatus, across the three OF sessions. In addition, during the first, but not the two consecutive sessions, both treatments prevented a thorough exploration of the OF. Altogether, these results confirm the crucial role played by the LHb in anxiety-related behaviours and further suggest its implication in the exploration of new anxiogenic environments.


Asunto(s)
Habénula , Ratas , Animales , Muscimol/farmacología , Agonistas de Receptores de GABA-A/farmacología , Antagonistas de Aminoácidos Excitadores/farmacología
17.
J Neurosci Res ; 101(6): 866-880, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-36634122

RESUMEN

The effects of a single and multiple doses of ginkgolide A, B, C, and bilobalide, active components of Ginkgo biloba extract (EGb 761), on absence seizures were investigated in male WAG/Rij rats, a genetic animal model of absence epilepsy. Furthermore, the interactions of ginkgolide A together with NMDA receptor antagonist MK-801, AMPA/kainate receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX), or L-type calcium channel blocker nicardipine were studied to figure out how ginkgolide A affects spike-wave discharges (SWDs) in the brain. The experiments were done using 6-8-month-old male WAG/Rij rats with infusion cannula and EEG electrode implanted. Ginkgolide A, B, C, and bilobalide were administered intraperitoneally for 7 days at a dose of 6 mg/kg. In interaction groups, 6 µg ginkgolide A was injected intracerebroventricularly in combination with MK-801 (10 µg), CNQX (1 µg), and nicardipine (50 µg) for 7 days. EEG was recorded from animals at the baseline, first dose, and seventh dose periods for 4 h. Ginkgolide A (p = .028), C (p = .046), and bilobalide (p = .043) significantly increased the frequency of SWDs in WAG/Rij rats. Ginkgolide A injected into the lateral ventricle with MK-801 (p = .046), CNQX (p = .043), and nicardipine (p = .046) significantly increased the number of SWDs after seventh dose. Finally, the EGb 761-related increase in absence epilepsy was determined to be caused by ginkgolide A, C, and bilobalide. All three receptor antagonists/channel blockers do not inhibit the pro-absence effect of ginkgolide A. The findings revealed that ginkgolide A's pro-absence effect is mediated by brain circuits other than ionotropic glutamate receptors or L-type calcium channels.


Asunto(s)
Bilobálidos , Epilepsia Tipo Ausencia , Ratas , Masculino , Animales , Epilepsia Tipo Ausencia/genética , 6-Ciano 7-nitroquinoxalina 2,3-diona , Maleato de Dizocilpina , Nicardipino , Ginkgólidos/farmacología , Antagonistas de Aminoácidos Excitadores/farmacología , Convulsiones/inducido químicamente , Convulsiones/tratamiento farmacológico , Electroencefalografía , Modelos Animales de Enfermedad
18.
Cell Mol Neurobiol ; 43(1): 139-153, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34978648

RESUMEN

NMDA receptors play an important physiological role in regulating synaptic plasticity, learning and memory. GluN2A subunits are the most abundant functional subunits of NMDA receptors expressed in mature brain, and their dysfunction is related to various neurological diseases. According to subunit composition, GluN2A-containing NMDA receptors can be divided into two types: diheteromeric and triheteromeric receptors. In this review, the expression, functional and pharmacological properties of different kinds of GluN2A-containing NMDA receptors as well as selective GluN2A regulators were described to further understand this type of NMDA receptors.


Asunto(s)
Plasticidad Neuronal , Receptores de N-Metil-D-Aspartato , Receptores de N-Metil-D-Aspartato/metabolismo , Antagonistas de Aminoácidos Excitadores/farmacología
19.
Eur J Neurosci ; 57(3): 440-455, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36226598

RESUMEN

In prodromal and early schizophrenia, disorders of attention and perception are associated with structural and chemical brain abnormalities and with dysfunctional corticothalamic networks exhibiting disturbed brain rhythms. The underlying mechanisms are elusive. The non-competitive NMDA receptor antagonist ketamine simulates the symptoms of prodromal and early schizophrenia, including disturbances in ongoing and task & sensory-related broadband beta-/gamma-frequency (17-29 Hz/30-80 Hz) oscillations in corticothalamic networks. In normal healthy subjects and rodents, complex integration processes, like sensory perception, induce transient, large-scale synchronised beta/gamma oscillations in a time window of a few hundred ms (200-700 ms) after the presentation of the object of attention (e.g., sensory stimulation). Our goal was to use an electrophysiological multisite network approach to investigate, in lightly anesthetised rats, the effects of a single psychotomimetic dose (2.5 mg/kg, subcutaneous) of ketamine on sensory stimulus-induced oscillations. Ketamine transiently increased the power of baseline beta/gamma oscillations and decreased sensory-induced beta/gamma oscillations. In addition, it disrupted information transferability in both the somatosensory thalamus and the related cortex and decreased the sensory-induced thalamocortical connectivity in the broadband gamma range. The present findings support the hypothesis that NMDA receptor antagonism disrupts the transfer of perceptual information in the somatosensory cortico-thalamo-cortical system.


Asunto(s)
Ketamina , Ratas , Animales , Ketamina/farmacología , Antagonistas de Aminoácidos Excitadores/farmacología , Receptores de N-Metil-D-Aspartato , Encéfalo , Tálamo
20.
Neuropharmacology ; 225: 109373, 2023 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-36502868

RESUMEN

Pathological accumulation of Aß oligomers has been linked to neuronal networks hyperexcitability, potentially underpinned by glutamatergic AMPA receptors (AMPARs) dysfunction. We aimed to investigate whether the non-competitive block of AMPARs was able to counteract the alteration of hippocampal epileptic threshold, and of synaptic plasticity linked to Aß oligomers accumulation, being this glutamate receptor a valuable specific therapeutic target. In this work, we showed that the non-competitive AMPARs antagonist perampanel (PER) which, per se, did not affect physiological synaptic transmission, was able to counteract Aß-induced hyperexcitability. Moreover, AMPAR antagonism was able to counteract Aß-induced hippocampal LTP impairment and hippocampal-based cognitive deficits in Aß oligomers-injected mice, while retaining antiseizure efficacy. Beside this, AMPAR antagonism was also able to reduce the increased expression of proinflammatory cytokines in this mice model, also suggesting the presence of an anti-inflammatory activity. Thus, targeting AMPARs might be a valuable strategy to reduce both hippocampal networks hyperexcitability and synaptic plasticity deficits induced by Aß oligomers accumulation.


Asunto(s)
Angiopatía Amiloide Cerebral , Disfunción Cognitiva , Antagonistas de Aminoácidos Excitadores , Hipocampo , Receptores AMPA , Animales , Ratones , Ácido alfa-Amino-3-hidroxi-5-metil-4-isoxazol Propiónico , Péptidos beta-Amiloides/metabolismo , Cognición/efectos de los fármacos , Antagonistas de Aminoácidos Excitadores/farmacología , Hipocampo/efectos de los fármacos , Hipocampo/fisiopatología , Receptores AMPA/antagonistas & inhibidores , Angiopatía Amiloide Cerebral/terapia , Disfunción Cognitiva/terapia
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