Despite the availability of new drugs on the clinics in recent years, drug-resistant epilepsy remains an unresolved challenge for healthcare, and one-third of epilepsy patients remain refractory to anti-seizure medications. Gene therapy in experimental models has emerged as effective treatment targeting specific neuronal populations in the epileptogenic focus. When combined with an external chemical activator using chemogenetics, it also becomes an "on-demand" treatment. Here, we evaluate a targeted and specific chemogenetic therapy, the PSAM/PSEM system, which holds promise as a potential candidate for clinical application in treating drug-resistant epilepsy. We show that the inert ligand uPSEM817, which selectively activates the chloride-permeable channel PSAM4-GlyR, effectively reduces the number of depolarization-induced action potentials in vitro. This effect is likely due to the shunting of depolarizing currents, as evidenced by decreased membrane resistance in these cells. In organotypic slices, uPSEM817 decreased the number of bursts and peak amplitude of events of spontaneous epileptiform activity. Although administration of uPSEM817 in vivo did not significantly alter electrographic seizures in a male mouse model of temporal lobe epilepsy, it did demonstrate a strong trend toward reducing the frequency of interictal epileptiform discharges. These findings indicate that PSAM4-GlyR-based chemogenetics holds potential as an anti-seizure strategy, although further refinement is necessary to enhance its efficacy.
- MeSH
- akční potenciály účinky léků MeSH
- epilepsie patofyziologie genetika farmakoterapie terapie metabolismus MeSH
- genetická terapie metody MeSH
- hipokampus * metabolismus MeSH
- lidé MeSH
- modely nemocí na zvířatech MeSH
- myši MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The formation of memories is a complex, multi-scale phenomenon, especially when it involves integration of information from various brain systems. We have investigated the differences between a novel and consolidated association of spatial cues and amphetamine administration, using an in situ hybridisation method to track the short-term dynamics during the recall testing. We have found that remote recall group involves smaller, but more consolidated groups of neurons, which is consistent with their specialisation. By employing machine learning analysis, we have shown this pattern is especially pronounced in the VTA; furthermore, we also uncovered significant activity patterns in retrosplenial and prefrontal cortices, as well as in the DG and CA3 subfields of the hippocampus. The behavioural propensity towards the associated localisation appears to be driven by the nucleus accumbens, however, further modulated by a trio of the amygdala, VTA and hippocampus, as the trained association is confronted with test experience. Moreover, chemogenetic analysis revealed central amygdala as critical for linking appetitive emotional states with spatial contexts. These results show that memory mechanisms must be modelled considering individual differences in motivation, as well as covering dynamics of the process.
- MeSH
- amfetamin farmakologie MeSH
- amygdala fyziologie MeSH
- hipokampus * fyziologie MeSH
- konsolidace paměti * fyziologie MeSH
- krysa rodu rattus MeSH
- mozek fyziologie MeSH
- neurony fyziologie metabolismus MeSH
- nucleus accumbens * fyziologie MeSH
- odměna * MeSH
- paměť fyziologie MeSH
- podněty MeSH
- prefrontální mozková kůra fyziologie MeSH
- rozpomínání * fyziologie MeSH
- strojové učení MeSH
- tegmentum mesencephali - area ventralis * fyziologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Developmental remodeling shapes neural circuits via activity-dependent pruning of synapses and axons. Regulation of the cytoskeleton is critical for this process, as microtubule loss via enzymatic severing is an early step of pruning across many circuits and species. However, how microtubule-severing enzymes, such as spastin, are activated in specific neuronal compartments remains unknown. Here, we reveal that polyglutamylation, a post-translational tubulin modification enriched in neurons, plays an instructive role in developmental remodeling by tagging microtubules for severing. Motor neuron-specific gene deletion of enzymes that add or remove tubulin polyglutamylation-TTLL glutamylases vs. CCP deglutamylases-accelerates or delays neuromuscular synapse remodeling in a neurotransmission-dependent manner. This mechanism is not specific to peripheral synapses but also operates in central circuits, e.g., the hippocampus. Thus, tubulin polyglutamylation acts as a cytoskeletal rheostat of remodeling that shapes neuronal morphology and connectivity.
- MeSH
- hipokampus metabolismus cytologie MeSH
- kyselina polyglutamová * metabolismus MeSH
- mikrotubuly * metabolismus MeSH
- motorické neurony * metabolismus MeSH
- myši MeSH
- nervosvalové spojení metabolismus MeSH
- nervový přenos MeSH
- neurony * metabolismus MeSH
- neuroplasticita * fyziologie MeSH
- peptidsynthasy metabolismus genetika MeSH
- posttranslační úpravy proteinů MeSH
- spastin metabolismus MeSH
- synapse metabolismus MeSH
- tubulin metabolismus MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
N-Methyl-d-aspartate receptors (NMDARs) play a crucial role in excitatory neurotransmission, with numerous pathogenic variants identified in the GluN subunits, including their ligand-binding domains (LBDs). The prevailing hypothesis postulates that the endoplasmic reticulum (ER) quality control machinery verifies the agonist occupancy of NMDARs, but this was tested in a limited number of studies. Using microscopy and electrophysiology in the human embryonic kidney 293 (HEK293) cells, we found that surface expression of GluN1/GluN2A receptors containing a set of alanine substitutions within the LBDs correlated with the measured EC50 values for glycine (GluN1 subunit mutations) while not correlating with the measured EC50 values for l-glutamate (GluN2A subunit mutations). The mutant cycle of GluN1-S688 residue, including the pathogenic GluN1-S688Y and GluN1-S688P variants, showed a correlation between relative surface expression of the GluN1/GluN2A receptors and the measured EC50 values for glycine, as well as with the calculated ΔGbinding values for glycine obtained from molecular dynamics simulations. In contrast, the mutant cycle of GluN2A-S511 residue did not show any correlation between the relative surface expression of the GluN1/GluN2A receptors and the measured EC50 values for l-glutamate or calculated ΔGbinding values for l-glutamate. Coexpression of both mutated GluN1 and GluN2A subunits led to additive or synergistic alterations in the surface number of GluN1/GluN2A receptors. The synchronized ER release by ARIAD technology confirmed the altered early trafficking of GluN1/GluN2A receptors containing the mutated LBDs. The microscopical analysis from embryonal rat hippocampal neurons (both sexes) corroborated our conclusions from the HEK293 cells.
- MeSH
- glycin metabolismus MeSH
- HEK293 buňky MeSH
- hipokampus cytologie metabolismus MeSH
- krysa rodu rattus MeSH
- kyselina glutamová metabolismus MeSH
- lidé MeSH
- ligandy MeSH
- mutace genetika MeSH
- proteinové domény MeSH
- proteiny nervové tkáně MeSH
- receptory N-methyl-D-aspartátu * metabolismus genetika chemie MeSH
- transport proteinů fyziologie genetika MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Mitochondria are central to cellular energy metabolism, contributing to synaptic transmission and plasticity. The mitochondrial membranes present the cannabinoid type-1 receptor (mito-CB1R), which has been functionally linked to neuronal energy supply and cognitive processing. Prenatal exposure to Δ9-tetrahydrocannabinol (pTHC) has been associated with cognitive impairments associated with molecular cellular and functional abnormalities in several brain regions, including the hippocampus. This study aims at assessing whether, besides the memory impairment, pTHC exposure may result in mitochondrial molecular and functional alterations in the hippocampus of the offspring. Moreover, the assessment of CB1R expression is also carried out as a proxy of CB1 signalling in pTHC-exposed offspring. THC (2 mg/Kg), or vehicle, was administered to the dams from gestational day (GD) 5 to GD20, and the offspring were tested for declarative memory using the Novel Object Recognition test in the L-maze. We also assessed: mitochondrial respiration by high-resolution respirometry; mitochondrial respiratory complex-I subunit NDUFS1 protein levels, and mito-CB1R expression by ELISA. Our results revealed: significant memory impairment in pTHC-exposed offspring; attenuated mitochondrial respiration in the hippocampus alongside a marked reduction in complex-I-subunit NDUFS1; a significant increase in mito-CB1R expression. This is the first evidence of pTHC exposure-induced impairment in memory processing in the offspring that suggests a functional link between an attenuation in mitochondrial bioenergetics and abnormal CB1R signalling in the hippocampus.
- MeSH
- bludiště - učení účinky léků MeSH
- buněčné dýchání účinky léků MeSH
- hipokampus * metabolismus účinky léků MeSH
- krysa rodu rattus MeSH
- mitochondrie * metabolismus účinky léků MeSH
- paměť účinky léků MeSH
- poruchy paměti * metabolismus chemicky indukované MeSH
- potkani Wistar MeSH
- receptor kanabinoidní CB1 * metabolismus MeSH
- těhotenství MeSH
- tetrahydrokanabinol * toxicita MeSH
- zpožděný efekt prenatální expozice * metabolismus chemicky indukované MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- těhotenství MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Psilocybin, a naturally occurring psychedelic compound in magic mushrooms, shows promise as a novel intervention with a single administration inducing rapid and long-lasting antidepressant effects. However, there are limited studies on the optimal dosing required for the beneficial effects of psilocybin given its side effects. To address this gap, we investigated in Wistar rats whether a single psilocybin administration (0.1, 0.32, 1.0, and 3.2 mg/kg) had antidepressant-like effects in the forced swim test (FST), a pro-social effect in the social interaction test (SIT), and the ability to alter pleasure using the sucrose preference test (SPT). We also examined the dose-response relationships of psilocybin on the head-twitch response (HTR), locomotor activity, body temperature, and weight gain. Furthermore, we explored whether the brain-derived neurotrophic factor (BDNF) levels in the hippocampus and prefrontal cortex (PFC) paralleled the behavioral changes observed after psilocybin. In the FST, psilocybin induced dose-dependent inverted-U-shaped responses with only the intermediate dose of 0.32 mg/kg producing short and long-term antidepressant-like effects. A similar pattern was observed for the SIT, the SPT, and the HTR. In contrast, the high doses of psilocybin (1.0 and 3.2 mg/kg), while deprived of anti-depressant-like activity, significantly reduced body temperature, locomotor activity, and body weight gain. BDNF levels in the hippocampus and PFC increased dose-dependently after psilocybin, but linearly suggesting a dissociation between high BDNF levels and the observed antidepressant-like behaviors. Our results indicated that there is a narrow window for the therapeutic potential of psilocybin, with 0.32 mg/kg effectively producing antidepressant-like effects without the accompanying adverse effects observed only at higher doses.
- MeSH
- antidepresiva * farmakologie terapeutické užití MeSH
- halucinogeny * farmakologie MeSH
- hipokampus účinky léků metabolismus MeSH
- krysa rodu rattus MeSH
- modely nemocí na zvířatech MeSH
- mozkový neurotrofický faktor metabolismus MeSH
- plavání psychologie MeSH
- pohybová aktivita účinky léků MeSH
- potkani Wistar MeSH
- prefrontální mozková kůra účinky léků metabolismus MeSH
- psilocybin * farmakologie terapeutické užití MeSH
- tělesná teplota účinky léků MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Elevated plasma homocysteine (Hcy) levels lead to hyperhomocysteinemia, a condition associated with various neurological disorders affecting multiple brain regions, including the hippocampus. In this study, we investigated the effects of exposing cultured rat hippocampal neurons to Hcy concentrations corresponding to mild, moderate, and severe hyperhomocysteinemia. A short 24-hour exposure had minimal effects, whereas prolonged exposure up to 14 days moderately enhanced hippocampal excitability without altering the gene expression of voltage-dependent calcium, sodium, or potassium channels or intracellular calcium levels. These findings suggest that Hcy-induced changes in neuronal excitability may contribute to neuropathologies associated with hyperhomocysteinemia.
- MeSH
- hipokampus * cytologie účinky léků MeSH
- homocystein * farmakologie MeSH
- iontové kanály * genetika metabolismus MeSH
- krysa rodu rattus MeSH
- kultivované buňky MeSH
- neurony * účinky léků metabolismus cytologie MeSH
- potkani Sprague-Dawley MeSH
- regulace genové exprese * účinky léků MeSH
- vápník metabolismus MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
To investigate the impact of hyperbaric oxygen therapy (HBOT) on the cognitive function of mice with Alzheimer's disease (AD), while also identifying the cellular pathways associated with autophagy involved in the treatment. Twenty-four APP/PSl double transgenic mice were randomly assigned to either Group A or Group B, while another 24 C57 mice were randomly allocated to Group C or Group D. HBOT was administered to mice in Group B and Group D, and the Morris water maze test was used to assess changes in mice behavior. Histological examination using hematoxylin and eosin staining was conducted to observe pathological alterations in the hippocampus of the mice brain tissue. Polymerase chain reaction (PCR) was employed to analyze autophagy-related gene pathways in the hippocampus of the mice. Following HBOT, mice in Group B exhibited a significant reduction in escape latency and a notable increase in residence time within the target quadrant compared with Group A (P<0.05), as well as Group C and Group D (P<0.01). The hippocampal neurons in Group A and Group B mice exhibited disorganized arrangements, characterized by pyknosis and margination. Conversely, neurons in Group C displayed orderly arrangements, retaining intact structures with round nuclei demonstrating clear nuclear staining and normal morphology. The cellular morphology of mice in Group D remained unaffected. PCR analysis revealed no notable disparity in autophagy-related gene expression between Group A and Group C. However, the expression levels of five genes including Tgfb1, Mapk14, Bid, Atg7, and Akt1, were significantly elevated in Group B compared to Group A. HBOT has the potential to improve the cognitive function in mice modeled with AD. This improvement of cognitive function appears to be mediated by the up-regulation of autophagy-related genes, specifically Tgfb1, Mapk14, Bid, Atg7, and Akt1. These results indicate that HBOT may offer a therapeutic strategy for treating AD by enhancing autophagy mechanisms. Key words Alzheimer's disease, Autophagy, Hyperbaric oxygen, Morris water maze, PCR.
- MeSH
- Alzheimerova nemoc * terapie metabolismus genetika psychologie MeSH
- autofagie * fyziologie MeSH
- hipokampus metabolismus patologie MeSH
- hyperbarická oxygenace * MeSH
- kognice * fyziologie MeSH
- lidé MeSH
- modely nemocí na zvířatech MeSH
- myši inbrední C57BL * MeSH
- myši transgenní * MeSH
- myši MeSH
- signální transdukce * MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Social withdrawal and deficits in social cognition are hallmarks of Alzheimer's disease (AD). While early deficits in social behavior and memory have been documented in mouse AD models, they remain understudied in rat models. Early-stage AD is accompanied by dysfunction of parvalbumin-positive (PV+) interneurons, implicating their potential connection to early symptoms. In this study, we employed a 5-trial social memory task to investigate early deficits in social cognition in 6-month-old TgF344-AD male and female rats. We counted the number of PV+ interneurons and recorded local field potentials during social interactions in the hippocampal CA2 - a region critical for social information processing. Our results show decreased social interest and novelty preference in TgF344-AD male and female rats. However, reduced PV+ interneuron numbers were observed only in female rats and specific to the CA2 area. The electrophysiological recordings revealed reduced theta-gamma phase-amplitude coupling in the CA2 during direct social interactions. We conclude that deficits in social cognition accompany early-stage AD in TgF344-AD rats and are potentially linked to PV+ interneuron and brain oscillatory dysfunction in the CA2 region of the hippocampus.
- MeSH
- Alzheimerova nemoc * patofyziologie patologie metabolismus MeSH
- hipokampální oblast CA2 * patofyziologie metabolismus patologie MeSH
- interneurony * metabolismus patologie MeSH
- krysa rodu rattus MeSH
- modely nemocí na zvířatech MeSH
- parvalbuminy * metabolismus MeSH
- pohlavní dimorfismus MeSH
- potkani inbrední F344 MeSH
- potkani transgenní MeSH
- sociální chování * MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
OBJECTIVE: Standard resective treatment of mesial temporal lobe epilepsy (MTLE) includes anteromesial temporal resection or amygdalohippocampectomy. One potential risk of these surgeries, especially in patients with magnetic resonance imaging (MRI)-negative findings, is postoperative memory impairment. An alternative to resective procedures that aim to preserve the neuropsychological profile are multiple hippocampal transections (MHTs). The objective of transections is to interrupt the longitudinal pathways of the hippocampus to prevent the spread of epileptic seizures while preserving the memory circuits. Previously performed MHT procedures were guided by questionable intraoperative electrocorticography. At our institution, we have developed and tested a modified technique to achieve complete MHTs. METHODS: Patients with pharmacoresistant unilaterally lateralized MTLE and MRI-negative findings with high risk of neuropsychologic deterioration were indicated for complete MHT. Comprehensive neuropsychological and epileptological evaluations and MRI follow-ups were conducted 1 year and 2 years postoperatively. The primary evaluated parameters were seizure reduction and significant changes in neuropsychological performance (± 1 SD). RESULTS: Complete MHTs were performed on 3 patients who completed 2-year follow-up. Two MHTs were performed on the right and 1 on the left side. Two patients are classified as Engel 1 and one patient as Engel 3. Two years after surgery, neuropsychologic evaluation did not show significant decrease in memory performance and performance in majority of cognitive tests. One-year MRI follow-up showed decrease of volume of hippocampus in all 3 patients. CONCLUSIONS: This modified technique of MHT in patients with MTLE and MRI-negative findings led to seizure reduction while preserving their neuropsychologic performance.
- MeSH
- dospělí MeSH
- epilepsie temporálního laloku * chirurgie diagnostické zobrazování MeSH
- hipokampus * chirurgie diagnostické zobrazování MeSH
- lidé středního věku MeSH
- lidé MeSH
- magnetická rezonanční tomografie MeSH
- mladý dospělý MeSH
- následné studie MeSH
- neurochirurgické výkony * metody MeSH
- neuropsychologické testy MeSH
- refrakterní epilepsie * chirurgie diagnostické zobrazování MeSH
- výsledek terapie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH