The mechanism of the negative impact of corticosteroids on the induction and progress of mental illness remains unclear. In this work, we studied the effects of corticosteroids on the activity of neuronal glycine receptors (GlyR) and GABA-A receptors (GABAAR) by measuring the chloride current induced by the application of GABA (2 or 5 μM) to isolated cerebellar Purkinje cells (IGABA) and by the application of glycine (100 μM) to pyramidal neurons of the rat hippocampus (IGly). It was found that corticosterone, 5α-dihydrodeoxycorticosterone, allotetrahydrocorticosterone, cortisol, and 17α,21-dihydroxypregnenolone were able to accelerate the desensitization of the IGly at physiological concentrations (IC50 values varying from 0.39 to 0.72 μM). Next, cortisone, 11-deoxycortisol, 11-deoxycorticosterone, 5β-dihydrodeoxycorticosterone, and tetrahydrocorticosterone accelerated the desensitization of IGly with IC50 values varying from 10.3 to 15.2 μM. Allotetrahydrocorticosterone and tetrahydrocorticosterone potentiated the IGABA albeit with high EC50 values (18-23 μM). The rest of the steroids had no effect on IGABA in the range of concentrations of 1-100 μM. Finally, our study has suggested a structural relationship of the 3β-hydroxyl group/3-oxo group with the selective modulatory activity on GlyRs in contrast to the 3α-hydroxyl group that is pivotal for GABAARs. In summary, our results suggest that increased GlyR desensitization by corticosteroids may contribute to brain dysfunction under chronic stress and identify corticosteroids for further development as selective modulators of GlyRs.

• Klíčová slova
• GABAA receptor, corticosteroids, glycine receptor, structure−activity relationship study,
• MeSH
• GABA farmakologie   MeSH
• glycin * farmakologie   MeSH
• hormony kůry nadledvin farmakologie   MeSH
• krysa rodu Rattus MeSH
• neurony MeSH
• receptory GABA-A MeSH
• receptory glycinu * fyziologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• GABA MeSH
• glycin * MeSH
• hormony kůry nadledvin MeSH
• receptory GABA-A MeSH
• receptory glycinu * MeSH

Multiple molecular targets have been identified to mediate membrane-delimited and nongenomic effects of natural and synthetic steroids, but the influence of steroid metabolism on neuroactive steroid signaling is not well understood. To begin to address this question, we set out to identify major metabolites of a neuroprotective synthetic steroid 20-oxo-5β-pregnan-3α-yl l-glutamyl 1-ester (pregnanolone glutamate, PAG) and characterize their effects on GABAA and NMDA receptors (GABARs, NMDARs) and their influence on zebrafish behavior. Gas chromatography-mass spectrometry was used to assess concentrations of PAG and its metabolites in the hippocampal tissue of juvenile rats following intraperitoneal PAG injection. PAG is metabolized in the peripheral organs and nervous tissue to 20-oxo-17α-hydroxy-5β-pregnan-3α-yl l-glutamyl 1-ester (17-hydroxypregnanolone glutamate, 17-OH-PAG), 3α-hydroxy-5β-pregnan-20-one (pregnanolone, PA), and 3α,17α-dihydroxy-5β-pregnan-20-one (17-hydroxypregnanolone, 17-OH-PA). Patch-clamp electrophysiology experiments in cultured hippocampal neurons demonstrate that PA and 17-OH-PA are potent positive modulators of GABARs, while PAG and 17-OH-PA have a moderate inhibitory effect at NMDARs. PAG, 17-OH-PA, and PA diminished the locomotor activity of zebrafish larvae in a dose-dependent manner. Our results show that PAG and its metabolites are potent modulators of neurotransmitter receptors with behavioral consequences and indicate that neurosteroid-based ligands may have therapeutic potential.

• Klíčová slova
• glutamate, negative allosteric modulator, steroid, thigmotaxis, zebrafish,
• MeSH
• dánio pruhované MeSH
• estery MeSH
• GABA MeSH
• krysa rodu Rattus MeSH
• kyselina glutamová MeSH
• pregnanolon * farmakologie   chemie   MeSH
• receptory GABA-A MeSH
• receptory N-methyl-D-aspartátu * MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• estery MeSH
• GABA MeSH
• kyselina glutamová MeSH
• pregnanolon * MeSH
• receptory GABA-A MeSH
• receptory N-methyl-D-aspartátu * MeSH

Stress responses are activated by the hypothalamic-pituitary-adrenal axis (HPA axis), culminating in the release of glucocorticoids. During prolonged periods of secretion of glucocorticoids or inappropriate behavioral responses to a stressor, pathologic conditions may occur. Increased glucocorticoid concentration is linked to generalized anxiety, and there are knowledge gaps regarding its regulation. It is known that the HPA axis is under GABAergic control, but the contribution of the individual subunits of the GABA receptor is largely unknown. In this study, we investigated the relationship between the α5 subunit and corticosterone levels in a new mouse model deficient for Gabra5, which is known to be linked to anxiety disorders in humans and phenologs observed in mice. We observed decreased rearing behavior, suggesting lower anxiety in the Gabra5-/- animals; however, such a phenotype was absent in the open field and elevated plus maze tests. In addition to decreased rearing behavior, we also found decreased levels of fecal corticosterone metabolites in Gabra5-/- mice indicating a lowered stress response. Moreover, based on the electrophysiological recordings where we observed a hyperpolarized state of hippocampal neurons, we hypothesize that the constitutive ablation of the Gabra5 gene leads to functional compensation with other channels or GABA receptor subunits in this model.

• Klíčová slova
• GABA receptor, anxiety, behavior, corticosterone, mouse model,
• MeSH
• glukokortikoidy * MeSH
• kortikosteron * MeSH
• lidé MeSH
• myši MeSH
• receptory GABA-A genetika   metabolismus   MeSH
• receptory GABA metabolismus   MeSH
• systém hypofýza - nadledviny metabolismus   MeSH
• systém hypotalamus-hypofýza metabolismus   MeSH
• úzkost MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• GABRA5 protein, human MeSH Prohlížeč
• Gabra5 protein, mouse MeSH Prohlížeč
• glukokortikoidy * MeSH
• kortikosteron * MeSH
• receptory GABA-A MeSH
• receptory GABA MeSH

The ability of endogenous neurosteroids (NSs) with pregnane skeleton modified at positions C-3 and C-5 to modulate the functional activity of inhibitory glycine receptors (GlyR) and ionotropic ɣ-aminobutyric acid receptors (GABAA R) was estimated. The glycine and GABA-induced chloride current (IGly and IGABA ) were measured in isolated pyramidal neurons of the rat hippocampus and in isolated rat cerebellar Purkinje cells, respectively. Our experiments demonstrated that pregnane NSs affected IGABA and IGly in a different manner. At low concentrations (up to 5 μM), tested pregnane NSs increased or did not change the peak amplitude of the IGABA , but reduced the IGly by decreasing the peak amplitude and/or accelerating desensitization. Namely, allopregnanolone (ALLO), epipregnanolone (EPI), pregnanolone (PA), pregnanolone sulfate (PAS) and 5β-dihydroprogesterone (5β-DHP) enhanced the IGABA in Purkinje cells. Dose-response curves plotted in the concentration range from 1 nM to 100 μM were smooth for EPI and 5β-DHP, but bell-shaped for ALLO, PA and PAS. The peak amplitude of the IGly was reduced by PA, PAS, and 5α- and 5β-DHP. In contrast, ALLO, ISO and EPI did not modulate it. Dose-response curves for the inhibition of the IGly peak amplitude were smooth for all active compounds. All NSs accelerated desensitization of the IGly . The dose-response relationship for this effect was smooth for ALLO, PA, PAS and 5β-DHP, but it was U-shaped for EPI, 5α-DHP and ISO. These results, together with our previous results on NSs with androstane skeleton, offer comprehensive overview for understanding the mechanisms of effects of NSs on IGly and IGABA .

• Klíčová slova
• GABAA receptor, glycine receptor, neurosteroid, pregnane, structure-activity relationship study,
• MeSH
• 5alfa-dihydroprogesteron farmakologie   MeSH
• chloridy farmakologie   MeSH
• GABA MeSH
• glycin farmakologie   MeSH
• krysa rodu Rattus MeSH
• neurony fyziologie   MeSH
• neurosteroidy * MeSH
• potkani Wistar MeSH
• pregnanolon * farmakologie   MeSH
• pregnany farmakologie   MeSH
• receptory GABA-A fyziologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 5alfa-dihydroprogesteron MeSH
• chloridy MeSH
• GABA MeSH
• glycin MeSH
• neurosteroidy * MeSH
• pregnanolon * MeSH
• pregnany MeSH
• receptory GABA-A MeSH

INTRODUCTION: Although there has been increasing recognition of the occurrence of non-epileptic involuntary movements in developmental and epileptic encephalopathies (DEEs), the spectrum of dystonic presentations associated with these conditions remains poorly described. We sought to expand the catalogue of dystonia-predominant phenotypes in monogenic DEEs, building on the recently introduced concept of an epilepsy-movement disorder spectrum. METHODS: Cases were identified from a whole-exome-sequenced cohort of 45 pediatric index patients with complex dystonia (67% sequenced as parent-child trios). Review of molecular findings in DEE-associated genes was performed. For five individuals with identified DEE-causing variants, detailed information about presenting phenotypic features and the natural history of disease was obtained. RESULTS: De-novo pathogenic and likely pathogenic missense variants in GABRA1, GABBR2, GNAO1, and FOXG1 gave rise to infantile-onset persistent and paroxysmal dystonic manifestations, beginning in the limb or truncal musculature and progressing gradually to a generalized state. Coexisting, less prominent movement-disorder symptoms were observed and included myoclonic, ballistic, and stereotypic abnormal movements as well as choreoathetosis. Dystonia dominated over epileptic neurodevelopmental comorbidities in all four subjects and represented the primary indication for molecular genetic analysis. We also report the unusual case of an adult female patient with dystonia, tremor, and mild learning disability who was found to harbor a pathogenic frameshift variant in MECP2. CONCLUSIONS: Dystonia can be a leading clinical manifestation in different DEEs. A monogenic basis of disease should be considered on the association of dystonia and developmental delay-epilepsy presentations, justifying a molecular screening for variants in DEE-associated genes.

• Klíčová slova
• Dystonia, Epilepsy, Epilepsy-dyskinesia spectrum, Neurodevelopmental disease,
• MeSH
• dítě MeSH
• dystonie genetika   MeSH
• epileptické syndromy komplikace   genetika   MeSH
• fenotyp MeSH
• forkhead transkripční faktory genetika   MeSH
• lidé MeSH
• mladiství MeSH
• nemoci mozku komplikace   genetika   MeSH
• neurovývojové poruchy komplikace   genetika   MeSH
• předškolní dítě MeSH
• protein 2 vázající methyl-CpG genetika   MeSH
• proteiny nervové tkáně genetika   MeSH
• proteiny vázající GTP - alfa-podjednotky Gi-Go genetika   MeSH
• receptory GABA-A genetika   MeSH
• receptory GABA-B genetika   MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• předškolní dítě MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH
• práce podpořená grantem MeSH
• Názvy látek
• forkhead transkripční faktory MeSH
• FOXG1 protein, human MeSH Prohlížeč
• GABBR2 protein, human MeSH Prohlížeč
• GABRA1 protein, human MeSH Prohlížeč
• GNAO1 protein, human MeSH Prohlížeč
• MECP2 protein, human MeSH Prohlížeč
• protein 2 vázající methyl-CpG MeSH
• proteiny nervové tkáně MeSH
• proteiny vázající GTP - alfa-podjednotky Gi-Go MeSH
• receptory GABA-A MeSH
• receptory GABA-B MeSH

Epipregnanolone (3β-hydroxy-5β-pregnan-20-one, Epi) is an endogenous steroid with important physiological effects and high affinity for GABAA receptors. The effect of Epi on GABA-induced chloride current (IGABA) in native neurons has hardly been studied. In this work, we studied the influence of Epi on the IGABA in the Purkinje cells of rat cerebellum and pyramidal neurons of rat hippocampus with the patch clamp technique. We showed that Epi is a positive modulator of the IGABA with EC50 of 5.7 µM in Purkinje cells and 9.3 µM in hippocampal neurons. Epi-induced potentiation of the IGABA was more potent at low vs. high GABA concentrations. Isopregnanolone (3β-hydroxy-5α-pregnan-20-one, Iso) counteracted Epi, reducing its potentiating effect by 2-2.3 times. Flumazenil, a nonsteroidal GABAA receptor antagonist, does not affect the Epi-induced potentiation. Comparison of the potentiating effects of Epi and allopregnanolone (3α-hydroxy-5α-pregnan-20-one, ALLO) showed that ALLO is, at least, a four times more potent positive modulator than Epi. The combined application of ALLO and Epi showed that the effects of these two steroids are not additive. We conclude that Epi has a dual effect on the IGABA increasing the current in the control solution and decreasing the stimulatory effect of ALLO.

• Klíčová slova
• GABA receptor, allopregnanolone, epipregnanolone, flumazenil patch clamp, isopregnanolone,
• MeSH
• agonisté receptorů GABA-A farmakologie   MeSH
• hipokampus metabolismus   MeSH
• krysa rodu Rattus MeSH
• mozeček metabolismus   MeSH
• potkani Wistar MeSH
• pregnanolon farmakologie   MeSH
• pyramidové buňky metabolismus   MeSH
• receptory GABA-A metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• agonisté receptorů GABA-A MeSH
• pregnanolon MeSH
• receptory GABA-A MeSH

BACKGROUND: Postictal potentiation presented immediately after cortical seizures in immature rats might be due to imbalance between excitation and inhibition. The aim of the present study was to determine whether augmentation of inhibition mediated by GABAA receptors could also suppress the postictal potentiation. METHODS: Twelve-day old rats with implanted electrodes were used in our study. Five drugs were tested: the agonist muscimol, the positive modulator midazolam and three neurosteroids affecting GABAA receptors-allopregnanolone, pregnanolone sulphate and pregnanolone glutamate. RESULTS: None of the five drugs was able to suppress potentiation appearing immediately after cortical epileptic afterdischarges, but all of them exhibited delayed anticonvulsant action 10 (in the case of midazolam and muscimol) or 20 min (all three steroids) after cortical seizures. CONCLUSION: Our results support a role of GABA in augmentation of cortical after discharges after longer intervals, whereas immediate postictal potentiation is not affected by GABAergic drugs. Due to similar effect with GABAergic drugs, the main mechanism of action of the three steroids tested is potentiation of GABAergic inhibition.

• Klíčová slova
• Cortical afterdischarges, Gabaergic drugs, Immature rats, Neurosteroids, Postictal potentiation,
• MeSH
• antikonvulziva farmakologie   MeSH
• časové faktory MeSH
• implantované elektrody MeSH
• krysa rodu Rattus MeSH
• midazolam farmakologie   MeSH
• modely nemocí na zvířatech MeSH
• muscimol farmakologie   MeSH
• neurosteroidy farmakologie   MeSH
• potkani Wistar MeSH
• receptory GABA-A účinky léků   metabolismus   MeSH
• záchvaty farmakoterapie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH
• Názvy látek
• antikonvulziva MeSH
• midazolam MeSH
• muscimol MeSH
• neurosteroidy MeSH
• receptory GABA-A MeSH

Benzodiazepines (BZDs) are widely used in patients of all ages. Unlike adults, neonatal animals treated with BZDs exhibit a variety of behavioral deficits later in life; however, the mechanisms underlying these deficits are poorly understood. This study aims to examine whether administration of clonazepam (CZP; 1 mg/kg/day) in 7-11-day-old rats affects Gama aminobutyric acid (GABA)ergic receptors in both the short and long terms. Using RT-PCR and quantitative autoradiography, we examined the expression of the selected GABAA receptor subunits (α1, α2, α4, γ2, and δ) and the GABAB B2 subunit, and GABAA, benzodiazepine, and GABAB receptor binding 48 h, 1 week, and 2 months after treatment discontinuation. Within one week after CZP cessation, the expression of the α2 subunit was upregulated, whereas that of the δ subunit was downregulated in both the hippocampus and cortex. In the hippocampus, the α4 subunit was downregulated after the 2-month interval. Changes in receptor binding were highly dependent on the receptor type, the interval after treatment cessation, and the brain structure. GABAA receptor binding was increased in almost all of the brain structures after the 48-h interval. BZD-binding was decreased in many brain structures involved in the neuronal networks associated with emotional behavior, anxiety, and cognitive functions after the 2-month interval. Binding of the GABAB receptors changed depending on the interval and brain structure. Overall, the described changes may affect both synaptic development and functioning and may potentially cause behavioral impairment.

• Klíčová slova
• GABAA/BZD receptor binding, GABAB receptor binding, clonazepam, neonatal rat, subunit mRNA expression,
• MeSH
• benzodiazepiny farmakologie   MeSH
• GABA metabolismus   MeSH
• hipokampus účinky léků   metabolismus   MeSH
• klonazepam farmakologie   MeSH
• krysa rodu Rattus MeSH
• kvantitativní polymerázová řetězová reakce MeSH
• mozek účinky léků   metabolismus   MeSH
• novorozená zvířata MeSH
• potkani inbrední WF MeSH
• receptory GABA-A metabolismus   MeSH
• receptory GABA-B metabolismus   MeSH
• vazba proteinů MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• benzodiazepiny MeSH
• GABA MeSH
• klonazepam MeSH
• receptory GABA-A MeSH
• receptory GABA-B MeSH

We studied the effects of GABA receptor agonists microinjections in medullary raphé on the mechanically induced tracheobronchial cough response in anesthetized, unparalyzed, spontaneously breathing cats. The results suggest that GABA-ergic inhibition significantly contributes to the regulation of cough reflex by action of both GABA(A) and GABA(B) receptors. The data are consistent with inhomogeneous occurrence of GABA-ergic neurons in medullary raphé and their different involvement in the cough reflex control. Cells within rostral nucleus raphéobscurus with dominant role of GABA(A) receptors and neurons of rostral nucleus raphépallidus and caudal nucleus raphémagnus with dominant role of GABA(B) receptors participate in regulation of cough expiratory efforts. These cough control elements are distinct from cough gating mechanism. GABA-ergic inhibition in the raphé caudal to obex had insignificant effect on cough. Contradictory findings for GABA, muscimol and baclofen administration in medullary raphé suggest involvement of coordinated activity of GABA on multiple receptors affecting raphé neurons and/or the local neuronal circuits in the raphé modulating cough motor drive.

• MeSH
• agonisté receptorů GABA-A farmakologie   terapeutické užití   MeSH
• agonisté receptorů GABA-B farmakologie   terapeutické užití   MeSH
• baklofen farmakologie   terapeutické užití   MeSH
• kašel farmakoterapie   patofyziologie   MeSH
• kočky MeSH
• medulla oblongata účinky léků   fyziologie   MeSH
• muscimol farmakologie   terapeutické užití   MeSH
• nuclei raphe účinky léků   fyziologie   MeSH
• receptory GABA-A fyziologie   MeSH
• receptory GABA-B fyziologie   MeSH
• reflex účinky léků   fyziologie   MeSH
• zvířata MeSH
• Check Tag
• kočky MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• agonisté receptorů GABA-A MeSH
• agonisté receptorů GABA-B MeSH
• baklofen MeSH
• muscimol MeSH
• receptory GABA-A MeSH
• receptory GABA-B MeSH

Inhibitory circuits in the auditory brainstem undergo multiple postnatal changes that are both activity-dependent and activity-independent. We tested to see if the shift from GABA- to glycinergic transmission, which occurs in the rat medial nucleus of the trapezoid body (MNTB) around the onset of hearing, depends on sound-evoked neuronal activity. We prevented the activity by bilateral cochlear ablations in early postnatal rats and studied ionotropic GABA and glycine receptors in MNTB neurons after hearing onset. The removal of the cochlea decreased responses of GABAA and glycine receptors to exogenous agonists as well as the amplitudes of inhibitory postsynaptic currents. The reduction was accompanied by a decrease in the number of glycine receptor- or vesicular GABA transporter-immunopositive puncta. Furthermore, the ablations markedly affected the switch in presynaptic GABAA to glycine receptors. The increase in the expression of postsynaptic glycine receptors and the shift in inhibitory transmitters were not prevented. The results suggest that inhibitory transmission in the MNTB is subject to multiple developmental signals and support the idea that auditory experience plays a role in the maturation of the brainstem glycinergic circuits.

• Klíčová slova
• Auditory, Cochlear ablation, GABA, Glycine, MNTB,
• MeSH
• ablace * MeSH
• agonisté receptorů GABA-A farmakologie   MeSH
• corpus trapezoideum fyziologie   MeSH
• inhibiční postsynaptické potenciály fyziologie   MeSH
• kochlea patofyziologie   chirurgie   MeSH
• krysa rodu Rattus MeSH
• nervový přenos * MeSH
• nervový útlum účinky léků   fyziologie   MeSH
• novorozená zvířata MeSH
• receptory GABA-A fyziologie   MeSH
• receptory glycinu agonisté   metabolismus   fyziologie   MeSH
• sluchové kmenové evokované potenciály fyziologie   MeSH
• transportéry VIAAT metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• agonisté receptorů GABA-A MeSH
• receptory GABA-A MeSH
• receptory glycinu MeSH
• transportéry VIAAT MeSH
• vesicular GABA transporter MeSH Prohlížeč