Electroencephalography (EEG) has been instrumental in epilepsy research for the past century, both for basic and translational studies. Its contributions have advanced our understanding of epilepsy, shedding light on the pathophysiology and functional organization of epileptic networks, and the mechanisms underlying seizures. Here we re-examine the historical significance, ongoing relevance, and future trajectories of EEG in epilepsy research. We describe traditional approaches to record brain electrical activity and discuss novel cutting-edge, large-scale techniques using micro-electrode arrays. Contemporary EEG studies explore brain potentials beyond the traditional Berger frequencies to uncover underexplored mechanisms operating at ultra-slow and high frequencies, which have proven valuable in understanding the principles of ictogenesis, epileptogenesis, and endogenous epileptogenicity. Integrating EEG with modern techniques such as optogenetics, chemogenetics, and imaging provides a more comprehensive understanding of epilepsy. EEG has become an integral element in a powerful suite of tools for capturing epileptic network dynamics across various temporal and spatial scales, ranging from rapid pathological synchronization to the long-term processes of epileptogenesis or seizure cycles. Advancements in EEG recording techniques parallel the application of sophisticated mathematical analyses and algorithms, significantly augmenting the information yield of EEG recordings. Beyond seizures and interictal activity, EEG has been instrumental in elucidating the mechanisms underlying epilepsy-related cognitive deficits and other comorbidities. Although EEG remains a cornerstone in epilepsy research, persistent challenges such as limited spatial resolution, artifacts, and the difficulty of long-term recording highlight the ongoing need for refinement. Despite these challenges, EEG continues to be a fundamental research tool, playing a central role in unraveling disease mechanisms and drug discovery.

• MeSH
• Electroencephalography * methods   MeSH
• Epilepsy * physiopathology   diagnosis   epidemiology   MeSH
• Comorbidity MeSH
• Humans MeSH
• Brain * physiopathology   MeSH
• Seizures * physiopathology   diagnosis   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Review MeSH

During GABAergic synaptic transmission, G protein-coupled GABAB receptors (GBRs) activate K+ channels that prolong the duration of inhibitory postsynaptic potentials (IPSPs). We now show that KCTD16, an auxiliary GBR subunit, anchors hyperpolarization-activated cyclic nucleotide-gated (HCN) channels containing HCN2/HCN3 subunits to GBRs. In dopamine neurons of the VTA (DAVTA neurons), this interaction facilitates activation of HCN channels via hyperpolarization during IPSPs, counteracting the GBR-mediated late phase of these IPSPs. Consequently, disruption of the GBR/HCN complex in KCTD16-/- mice leads to prolonged optogenetic inhibition of DAVTA neuron firing. KCTD16-/- mice exhibit increased anxiety-like behavior in response to stress - a behavior replicated by CRISPR/Cas9-mediated KCTD16 ablation in DAVTA neurons or by intra-VTA infusion of an HCN antagonist in wild-type mice. Our findings support that the retention of HCN channels at GABAergic synapses by GBRs in DAVTA neurons provides a negative feedback mechanism that restricts IPSP duration and mitigates the development of anxiety.

• MeSH
• Dopaminergic Neurons * metabolism   MeSH
• Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels * metabolism   genetics   MeSH
• Inhibitory Postsynaptic Potentials physiology   drug effects   MeSH
• Mice, Inbred C57BL MeSH
• Mice, Knockout MeSH
• Mice MeSH
• Receptors, GABA-B * metabolism   MeSH
• Ventral Tegmental Area * metabolism   MeSH
• Anxiety * metabolism   MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Mice MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH

Single-photon optogenetics enables precise, cell-type-specific modulation of neuronal circuits, making it a crucial tool in neuroscience. Its miniaturization in the form of fully implantable wide-field stimulator arrays enables long-term interrogation of cortical circuits and bears promise for brain-machine interfaces for sensory and motor function restoration. However, achieving selective activation of functional cortical representations poses a challenge, as studies show that targeted optogenetic stimulation results in activity spread beyond one functional domain. While recurrent network mechanisms contribute to activity spread, here we demonstrate with detailed simulations of isolated pyramidal neurons from cats of unknown sex that already neuron morphology causes a complex spread of optogenetic activity at the scale of one cortical column. Since the shape of a neuron impacts its optogenetic response, we find that a single stimulator at the cortical surface recruits a complex spatial distribution of neurons that can be inhomogeneous and vary with stimulation intensity and neuronal morphology across layers. We explore strategies to enhance stimulation precision, finding that optimizing stimulator optics may offer more significant improvements than the preferentially somatic expression of the opsin through genetic targeting. Our results indicate that, with the right optical setup, single-photon optogenetics can precisely activate isolated neurons at the scale of functional cortical domains spanning several hundred micrometers.

• MeSH
• Cats MeSH
• Models, Neurological MeSH
• Cerebral Cortex physiology   cytology   MeSH
• Neurons physiology   MeSH
• Optogenetics * methods   MeSH
• Pyramidal Cells physiology   MeSH
• Photic Stimulation methods   MeSH
• Animals MeSH
• Check Tag
• Cats MeSH
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH

T-tubules (TT) form a complex network of sarcolemmal membrane invaginations, essential for well-co-ordinated excitation-contraction coupling (ECC) and thus homogeneous mechanical activation of cardiomyocytes. ECC is initiated by rapid depolarization of the sarcolemmal membrane. Whether TT membrane depolarization is active (local generation of action potentials; AP) or passive (following depolarization of the outer cell surface sarcolemma; SS) has not been experimentally validated in cardiomyocytes. Based on the assessment of ion flux pathways needed for AP generation, we hypothesize that TT are excitable. We therefore explored TT excitability experimentally, using an all-optical approach to stimulate and record trans-membrane potential changes in TT that were structurally disconnected, and hence electrically insulated, from the SS membrane by transient osmotic shock. Our results establish that cardiomyocyte TT can generate AP. These AP show electrical features that differ substantially from those observed in SS, consistent with differences in the density of ion channels and transporters in the two different membrane domains. We propose that TT-generated AP represent a safety mechanism for TT AP propagation and ECC, which may be particularly relevant in pathophysiological settings where morpho-functional changes reduce the electrical connectivity between SS and TT membranes. KEY POINTS: Cardiomyocytes are characterized by a complex network of membrane invaginations (the T-tubular system) that propagate action potentials to the core of the cell, causing uniform excitation-contraction coupling across the cell. In the present study, we investigated whether the T-tubular system is able to generate action potentials autonomously, rather than following depolarization of the outer cell surface sarcolemma. For this purpose, we developed a fully optical platform to probe and manipulate the electrical dynamics of subcellular membrane domains. Our findings demonstrate that T-tubules are intrinsically excitable, revealing distinct characteristics of self-generated T-tubular action potentials. This active electrical capability would protect cells from voltage drops potentially occurring within the T-tubular network.

• MeSH
• Action Potentials physiology   MeSH
• Cell Membrane MeSH
• Myocytes, Cardiac * metabolism   MeSH
• Membrane Potentials MeSH
• Optogenetics * MeSH
• Sarcolemma metabolism   MeSH
• Publication type
• Journal Article MeSH

High-frequency oscillations (HFOs) represent an electrographic biomarker of endogenous epileptogenicity and seizure-generating tissue that proved clinically useful in presurgical planning and delineating the resection area. In the neocortex, the clinical observations on HFOs are not sufficiently supported by experimental studies stemming from a lack of realistic neocortical epilepsy models that could provide an explanation of the pathophysiological substrates of neocortical HFOs. In this study, we explored pathological epileptiform network phenomena, particularly HFOs, in a highly realistic murine model of neocortical epilepsy due to focal cortical dysplasia (FCD) type II. FCD was induced in mice by the expression of the human pathogenic mTOR gene mutation during embryonic stages of brain development. Electrographic recordings from multiple cortical regions in freely moving animals with FCD and epilepsy demonstrated that the FCD lesion generates HFOs from all frequency ranges, i.e., gamma, ripples, and fast ripples up to 800 Hz. Gamma-ripples were recorded almost exclusively in FCD animals, while fast ripples occurred in controls as well, although at a lower rate. Gamma-ripple activity is particularly valuable for localizing the FCD lesion, surpassing the utility of fast ripples that were also observed in control animals, although at significantly lower rates. Propagating HFOs occurred outside the FCD, and the contralateral cortex also generated HFOs independently of the FCD, pointing to a wider FCD network dysfunction. Optogenetic activation of neurons carrying mTOR mutation and expressing Channelrhodopsin-2 evoked fast ripple oscillations that displayed spectral and morphological profiles analogous to spontaneous oscillations. This study brings experimental evidence that FCD type II generates pathological HFOs across all frequency bands and provides information about the spatiotemporal properties of each HFO subtype in FCD. The study shows that mutated neurons represent a functionally interconnected and active component of the FCD network, as they can induce interictal epileptiform phenomena and HFOs.

• MeSH
• Electroencephalography MeSH
• Epilepsy * MeSH
• Focal Cortical Dysplasia * MeSH
• Humans MeSH
• Disease Models, Animal MeSH
• Mice MeSH
• TOR Serine-Threonine Kinases MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Mice MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH

Schizophrenia research has increased in recent decades and focused more on its neural basis. Decision-making and cognitive flexibility are the main cognitive functions that are impaired and considered schizophrenia endophenotypes. Cognitive impairment was recently connected with altered functions of N-methyl-d-aspartate (NMDAR) glutamatergic receptors, which increased cortical activity. Selective NMDAR antagonists, such as MK-801, have been used to model cognitive inflexibility in schizophrenia. Decreased GABAergic inhibitory activity has been shown elsewhere with enhanced cortical activity. This imbalance in the excitatory/inhibitory may reduce the entrainment of prefrontal gamma and hippocampal theta rhythms and result in gamma/theta band de-synchronization. The current study established an acute MK-801 administration model of schizophrenia-like cognitive inflexibility in rats and used the attentional set-shifting task in which rats learned to switch/reverse the relevant rule. During the task, we used in vivo optogenetic stimulations of parvalbumin-positive interneurons at specific light pulses in the prefrontal cortex and ventral hippocampus. The first experiments showed that acute dizocilpine in rats produced schizophrenia-like cognitive inflexibility. The second set of experiments demonstrated that specific optogenetic stimulation at specific frequencies of parvalbumin-positive interneurons in the prefrontal cortex and ventral hippocampus rescued the cognitive flexibility rats that received acute MK-801. These findings advance our knowledge of the pivotal role of parvalbumin interneurons in schizophrenia-like cognitive impairment and may guide further research on this severe psychiatric disorder.

• MeSH
• Dizocilpine Maleate * pharmacology   MeSH
• Hippocampus metabolism   MeSH
• Interneurons metabolism   MeSH
• Cognition MeSH
• Rats MeSH
• Optogenetics MeSH
• Parvalbumins metabolism   MeSH
• Prefrontal Cortex metabolism   MeSH
• Receptors, N-Methyl-D-Aspartate metabolism   MeSH
• Schizophrenia * MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

• MeSH
• Brain * physiology   MeSH
• Mice MeSH
• Neurons physiology   MeSH
• Optogenetics * methods   MeSH
• Mammals MeSH
• Check Tag
• Mice MeSH

The development of painful paclitaxel-induced peripheral neuropathy (PIPN) represents a major dose-limiting side effect of paclitaxel chemotherapy. Here we report a promising effect of duvelisib (Copiktra), a novel FDA-approved PI3Kδ/γ isoform-specific inhibitor, in preventing paclitaxel-induced pain-like behavior and pronociceptive signaling in DRGs and spinal cord dorsal horn (SCDH) in rat and mouse model of PIPN. Duvelisib blocked the development of mechanical hyperalgesia in both males and females. Moreover, duvelisib prevented paclitaxel-induced sensitization of TRPV1 receptors, and increased PI3K/Akt signaling in small-diameter DRG neurons and an increase of CD68+ cells within DRGs. Specific optogenetic stimulation of inhibitory neurons combined with patch-clamp recording revealed that duvelisib inhibited paclitaxel-induced weakening of inhibitory, mainly glycinergic control on SCDH excitatory neurons. Enhanced excitatory and reduced inhibitory neurotransmission in the SCDH following PIPN was also alleviated by duvelisib application. In summary, duvelisib showed a promising ability to prevent neuropathic pain in PIPN. The potential use of our findings in human medicine may be augmented by the fact that duvelisib is an FDA-approved drug with known side effects.SIGNIFICANCE STATEMENT We show that duvelisib, a novel FDA-approved PI3Kδ/γ isoform-specific inhibitor, prevents the development of paclitaxel-induced pain-like behavior in males and females and prevents pronociceptive signaling in DRGs and spinal cord dorsal horn in rat and mouse model of paclitaxel-induced peripheral neuropathy.

• MeSH
• Pain MeSH
• Phosphatidylinositol 3-Kinases MeSH
• Antineoplastic Agents, Phytogenic * pharmacology   MeSH
• Hyperalgesia chemically induced   drug therapy   prevention & control   MeSH
• Isoquinolines MeSH
• Rats MeSH
• Mice MeSH
• Peripheral Nervous System Diseases MeSH
• Neuralgia * chemically induced   drug therapy   prevention & control   MeSH
• Paclitaxel adverse effects   MeSH
• Purines MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Male MeSH
• Mice MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

Epilepsy is a complex disorder affecting the central nervous system and is characterised by spontaneously recurring seizures (SRSs). Epileptic patients undergo symptomatic pharmacological treatments, however, in 30% of cases, they are ineffective, mostly in patients with temporal lobe epilepsy. Therefore, there is a need for developing novel treatment strategies. Transplantation of cells releasing γ-aminobutyric acid (GABA) could be used to counteract the imbalance between excitation and inhibition within epileptic neuronal networks. We generated GABAergic interneuron precursors from human embryonic stem cells (hESCs) and grafted them in the hippocampi of rats developing chronic SRSs after kainic acid-induced status epilepticus. Using whole-cell patch-clamp recordings, we characterised the maturation of the grafted cells into functional GABAergic interneurons in the host brain, and we confirmed the presence of functional inhibitory synaptic connections from grafted cells onto the host neurons. Moreover, optogenetic stimulation of grafted hESC-derived interneurons reduced the rate of epileptiform discharges in vitro. We also observed decreased SRS frequency and total time spent in SRSs in these animals in vivo as compared to non-grafted controls. These data represent a proof-of-concept that hESC-derived GABAergic neurons can exert a therapeutic effect on epileptic animals presumably through establishing inhibitory synapses with host neurons.

• MeSH
• gamma-Aminobutyric Acid metabolism   MeSH
• Hippocampus metabolism   pathology   MeSH
• Interneurons cytology   metabolism   MeSH
• Stem Cells cytology   metabolism   MeSH
• Rats MeSH
• Cells, Cultured MeSH
• Kainic Acid adverse effects   MeSH
• Humans MeSH
• Disease Models, Animal MeSH
• Recurrence MeSH
• Status Epilepticus chemically induced   metabolism   pathology   therapy   MeSH
• Stem Cell Transplantation methods   MeSH
• Seizures chemically induced   metabolism   pathology   therapy   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Humans MeSH
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH

Poruchy kognitivních funkcí jsou považovány za klíčový příznak schizofrenie a předpovídají terapeutický výsledek. Velmi významně narušují denní fungování pacientů se schizofrenií, a přesto dosud neexistuje cílená léčba kognitivního deficitu u schizofrenie. V tomto translačním projektu plánujeme objasnit kauzální roli hipokampálně-prefrontálních projekcí v kognitivní koordinace a flexibilitě. Rovněž ukážeme na příčinnou roli frontotemporální theta koherence a synchronie pomocí optogenetické kontroly aktivity PV+ interneuronů u volně pohyblivých potkanů. V klinické části otestujeme vliv frontotemporální synchronizace na kognitivní koordinaci a flexibilitu ve skupině 35 pacientů v remisi a u 35 zdravých kontrol s využitím hrEEG/fMRI měření a testů virtuální reality. Hlavním cílem je objasnění neurobiologického substrátu kognitivního deficitu u schizofrenie, které umožní inteligentní design nových léčebných postupů. Výsledky projektu jednoznačně ukážou složky frontotemporální dysfunkce u schizofrenie a otevřou cestu pro budoucí specifickou terapii kognitivního deficitu.; Disturbances of cognitive functions have been recognized as hallmarks of schizophrenia and predictors of therapeutic outcome. They significantly limit patient ́s functioning, yet there are no specific treatments for cognitive deficits in this disease. In this translational project, we seek to determine the causal role of hippocampal-prefrontal projections in cognitive coordination and flexibility. Moreover, causative role of frontotemporal theta coherence and synchrony will be revealed by controlling PV+ interneuron activity in freely-moving rats. The human part will test relations of frontotemporal synchrony to coordination and flexibility in 35 remitted schizophrenia patients and 35 matched healthy controls using a hrEEG/fMRI measurements and tests of the virtual reality. The overall aim is to elucidate a neuronal substrate for cognitive deficits in schizophrenia for an intelligent design of new treatments. Results of this project will unequivocally show the constituents of frontotemporal dysfunction in schizophrenia and open way for future treatment of cognitive deficits.

• MeSH
• Electroencephalography MeSH
• Hippocampus MeSH
• Cognitive Dysfunction etiology   physiopathology   MeSH
• Rats MeSH
• Humans MeSH
• Magnetic Resonance Imaging MeSH
• Disease Models, Animal MeSH
• Synaptic Transmission MeSH
• Neuroimaging MeSH
• Optogenetics MeSH
• Prefrontal Cortex MeSH
• Schizophrenia diagnosis   MeSH
• Translational Research, Biomedical MeSH
• Virtual Reality MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Humans MeSH
• Animals MeSH

• Conspectus
• Patologie. Klinická medicína
• NML Fields
• neurologie
• psychiatrie
• NML Publication type
• závěrečné zprávy o řešení grantu AZV MZ ČR