The interaction between the main psychotropic ingredient of Cannabis, Δ9- tetrahydrocannabinol (THC), with the endogenous cannabinoid system (ECS) is a critical and underrated issue that deserves utmost attention. The ECS, indeed, contributes to the formation and regulation of excitatory and inhibitory (E/I) neuronal networks that in the hippocampus underly spatial memory. This study explored sex-specific consequences of prenatal exposure to THC in hippocampus-dependent memory and the underlying cellular and molecular contributors of synaptic plasticity and E/I homeostasis. Sprague Dawley dams were exposed to THC (2 mg/kg) or vehicle, from gestational day 5-20. The adolescent progeny of both sexes was tested for: spatial memory retrieval and flexibility in the Barnes Maze; mRNA expression of relevant players of hippocampal synaptic plasticity; density of cholecystokinin-positive basket cells (CCK+BCs) - a major subtype of hippocampal inhibitory interneurons; mRNA expression of the excitatory and inhibitory synaptic proteins neuroligins (Nlgns), as a proxy of synaptic efficiency. Our results show a sex-specific disruption in spatial memory retrieval and flexibility, a male-specific decrease in CCK+BCs density and increase in the expression of markers of neuroplasticity, and consistent changes in the expression of Nlgn-1 and 3 isoforms. Despite a delay in memory retrieval, flexibility of memory was spared in prenatally-THC-exposed female offspring as well as most of the markers of neuroplasticity; a sex-specific increase in CCK+BCs density, and a consistent expression of Nlgn-3 was observed. The current results highlight a major vulnerability to prenatal exposure to THC on memory processing in the male progeny, and sex-specific alterations in the E/I balance and synaptic plasticity.

• MeSH
• bludiště - učení účinky léků   MeSH
• cholecystokinin metabolismus   MeSH
• hipokampus * účinky léků   metabolismus   MeSH
• krysa rodu rattus MeSH
• neuroplasticita * účinky léků   MeSH
• pohlavní dimorfismus * MeSH
• potkani Sprague-Dawley * MeSH
• prostorová paměť * účinky léků   MeSH
• těhotenství MeSH
• tetrahydrokanabinol * farmakologie   toxicita   MeSH
• zpožděný efekt prenatální expozice * 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

BACKGROUND: Major depressive disorder (MDD) is a mental illness with a high worldwide prevalence and suboptimal pharmacological treatment, which necessitates the development of novel, more efficacious MDD medication. Nuclear magnetic resonance (NMR) can non-invasively provide insight into the neurochemical state of the brain using proton magnetic resonance spectroscopy (1H MRS), and an assessment of regional cerebral blood flow (rCBF) by perfusion imaging. These methods may provide valuable in vivo markers of the pathological processes underlying MDD. METHODS: This study examined the effects of the chronic antidepressant medication, citalopram, in a well-validated MDD model induced by bilateral olfactory bulbectomy (OB) in rats. 1H MRS was utilized to assess key metabolite ratios in the dorsal hippocampus and sensorimotor cortex bilaterally, and arterial spin labelling was employed to estimate rCBF in several additional brain regions. RESULTS: The 1H MRS data results suggest lower hippocampal Cho/tCr and lower cortical NAA/tCr levels as a characteristic of the OB phenotype. Spectroscopy revealed lower hippocampal Tau/tCr in citalopram-treated rats, indicating a potentially deleterious effect of the drug. However, the significant OB model-citalopram treatment interaction was observed using 1H MRS in hippocampal mI/tCr, Glx/tCr and Gln/tCr, indicating differential treatment effects in the OB and control groups. The perfusion data revealed higher rCBF in the whole brain, hippocampus and thalamus in the OB rats, while citalopram appeared to normalise it without affecting the control group. CONCLUSION: Collectively, 1H MRS and rCBF approaches demonstrated their capacity to capture an OB-induced phenotype and chronic antidepressant treatment effect in multiple brain regions.

• MeSH
• bulbus olfactorius metabolismus   chirurgie   účinky léků   MeSH
• citalopram * farmakologie   MeSH
• deprese farmakoterapie   metabolismus   MeSH
• depresivní porucha unipolární farmakoterapie   metabolismus   MeSH
• hipokampus metabolismus   účinky léků   MeSH
• krysa rodu rattus MeSH
• magnetická rezonanční spektroskopie metody   MeSH
• modely nemocí na zvířatech * MeSH
• mozek * metabolismus   účinky léků   MeSH
• mozkový krevní oběh * účinky léků   MeSH
• potkani Sprague-Dawley MeSH
• protonová magnetická rezonanční spektroskopie MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

AMPA glutamate receptors (AMPARs) are ion channel tetramers that mediate the majority of fast excitatory synaptic transmission. They are composed of four subunits (GluA1-GluA4); the GluA2 subunit dominates AMPAR function throughout the forebrain. Its extracellular N-terminal domain (NTD) determines receptor localization at the synapse, ensuring reliable synaptic transmission and plasticity. This synaptic anchoring function requires a compact NTD tier, stabilized by a GluA2-specific NTD interface. Here we show that low pH conditions, which accompany synaptic activity, rupture this interface. All-atom molecular dynamics simulations reveal that protonation of an interfacial histidine residue (H208) centrally contributes to NTD rearrangement. Moreover, in stark contrast to their canonical compact arrangement at neutral pH, GluA2 cryo-electron microscopy structures exhibit a wide spectrum of NTD conformations under acidic conditions. We show that the consequences of this pH-dependent conformational control are twofold: rupture of the NTD tier slows recovery from desensitized states and increases receptor mobility at mouse hippocampal synapses. Therefore, a proton-triggered NTD switch will shape both AMPAR location and kinetics, thereby impacting synaptic signal transmission.

• MeSH
• AMPA receptory * metabolismus   chemie   MeSH
• elektronová kryomikroskopie * MeSH
• hipokampus metabolismus   MeSH
• kinetika MeSH
• koncentrace vodíkových iontů MeSH
• konformace proteinů MeSH
• lidé MeSH
• myši MeSH
• nervový přenos MeSH
• proteinové domény MeSH
• protony * MeSH
• simulace molekulární dynamiky * MeSH
• synapse * metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

N-Methyl-d-aspartate receptors (NMDARs), encoded by GRIN genes, are ionotropic glutamate receptors playing a critical role in synaptic transmission, plasticity, and synapse development. Genome sequence analyses have identified variants in GRIN genes in patients with neurodevelopmental disorders, but the underlying disease mechanisms are not well understood. Here, we have created and evaluated a transgenic mouse line carrying a missense variant Grin2bL825V , corresponding to a de novo GRIN2B variant encoding GluN2B(L825V) found in a patient with intellectual disability (ID) and autism spectrum disorder (ASD). We used HEK293T cells expressing recombinant receptors and primary hippocampal neurons prepared from heterozygous Grin2bL825V/+ (L825V/+) and wild-type (WT) Grin2b+/+ (+/+) male and female mice to assess the functional impact of the variant. Whole-cell NMDAR currents were reduced in neurons from L825V/+ compared with +/+ mice. The peak amplitude of NMDAR-mediated evoked excitatory postsynaptic currents (NMDAR-eEPSCs) was unchanged, but NMDAR-eEPSCs in L825V/+ neurons had faster deactivation compared with +/+ neurons and were less sensitive to a GluN2B-selective antagonist ifenprodil. Together, these results suggest a decreased functional contribution of GluN2B subunits to synaptic NMDAR currents in hippocampal neurons from L825V/+ mice. The analysis of the GluN2B(L825V) subunit surface expression and synaptic localization revealed no differences compared with WT GluN2B. Behavioral testing of mice of both sexes demonstrated hypoactivity, anxiety, and impaired sensorimotor gating in the L825V/+ strain, particularly affecting males, as well as cognitive symptoms. The heterozygous L825V/+ mouse offers a clinically relevant model of GRIN2B-related ID/ASD, and our results suggest synaptic-level functional changes that may contribute to neurodevelopmental pathology.

• MeSH
• excitační postsynaptické potenciály fyziologie   MeSH
• HEK293 buňky MeSH
• hipokampus metabolismus   MeSH
• lidé MeSH
• missense mutace MeSH
• myši inbrední C57BL MeSH
• myši transgenní * MeSH
• myši MeSH
• neurony metabolismus   MeSH
• neurovývojové poruchy * genetika   patofyziologie   metabolismus   MeSH
• receptory N-methyl-D-aspartátu * genetika   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

N-methyl-D-aspartate receptors (NMDARs) play a significant role in developing several central nervous system (CNS) disorders. Currently, memantine, used for treating Alzheimer's disease, and ketamine, known for its anesthetic and antidepressant properties, are two clinically used NMDAR open-channel blockers. However, despite extensive research into NMDAR modulators, many have shown either harmful side effects or inadequate effectiveness. For instance, dizocilpine (MK-801) is recognized for its powerful psychomimetic effects due to its high-affinity and nearly irreversible inhibition of the GluN1/GluN2 NMDAR subtypes. Unlike ketamine, memantine and MK-801 also act through a unique, low-affinity "membrane-to-channel inhibition" (MCI). We aimed to develop an open-channel blocker based on MK-801 with distinct inhibitory characteristics from memantine and MK-801. Our novel compound, K2060, demonstrated effective voltage-dependent inhibition in the micromolar range at key NMDAR subtypes, GluN1/GluN2A and GluN1/GluN2B, even in the presence of Mg2+. K2060 showed reversible inhibitory dynamics and a partially trapping open-channel blocking mechanism with a significantly stronger MCI than memantine. Using hippocampal slices, 30 μM K2060 inhibited excitatory postsynaptic currents in CA1 hippocampal neurons by ∼51 %, outperforming 30 μM memantine (∼21 % inhibition). K2060 exhibited No Observed Adverse Effect Level (NOAEL) of 15 mg/kg upon intraperitoneal administration in mice. Administering K2060 at a 10 mg/kg dosage resulted in brain concentrations of approximately 2 μM, with peak concentrations (Tmax) achieved within 15 minutes. Finally, applying K2060 with trimedoxime and atropine in mice exposed to tabun improved treatment outcomes. These results underscore K2060's potential as a therapeutic agent for CNS disorders linked to NMDAR dysfunction.

• MeSH
• antagonisté excitačních aminokyselin farmakologie   MeSH
• dizocilpinmaleát * farmakologie   MeSH
• excitační postsynaptické potenciály účinky léků   MeSH
• hipokampus účinky léků   metabolismus   MeSH
• lidé MeSH
• memantin farmakologie   MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• neurony účinky léků   metabolismus   MeSH
• receptory N-methyl-D-aspartátu * antagonisté a inhibitory   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Structural neuroplasticity such as neurite extension and dendritic spine dynamics is enhanced by brain-derived neurotrophic factor (BDNF) and impaired by types of inhibitory molecules that induce growth cone collapse and actin depolymerization, for example, myelin-associated inhibitors, chondroitin sulfate proteoglycans, and negative guidance molecules. These inhibitory molecules can activate RhoA/rho-associated coiled-coil containing protein kinase (ROCK) signaling (known to restrict structural plasticity). Intermittent hypoxia (IH) and high-intensity interval training (HIIT) are known to upregulate BDNF that is associated with improvements in learning and memory and greater functional recovery following neural insults. We investigated whether the RhoA/ROCK signaling pathway is also modulated by IH and HIIT in the hippocampus, cortex, and lumbar spinal cord of male Wistar rats. The gene expression of 25 RhoA/ROCK signaling pathway components was determined following IH, HIIT, or IH combined with HIIT (30 min/day, 5 days/wk, 6 wk). IH included 10 3-min bouts that alternated between hypoxia (15% O2) and normoxia. HIIT included 10 3-min bouts alternating between treadmill speeds of 50 cm·s-1 and 15 cm·s-1. In the hippocampus, IH and HIIT significantly downregulated Acan and NgR2 mRNA that are involved in the inhibition of neuroplasticity. However, IH and IH + HIIT significantly upregulated Lingo-1 and NgR3 in the cortex. This is the first time IH and HIIT have been linked to the modulation of plasticity-inhibiting pathways. These results provide a fundamental step toward elucidating the interplay between the neurotrophic and inhibitory mechanisms involved in experience-driven neural plasticity that will aid in optimizing physiological interventions for the treatment of cognitive decline or neurorehabilitation.NEW & NOTEWORTHY Intermittent hypoxia (IH) and high-intensity interval training (HIIT) enhance neuroplasticity and upregulate neurotrophic factors in the central nervous system (CNS). We provide evidence that IH and IH + HIIT also have the capacity to regulate genes involved in the RhoA/ROCK signaling pathway that is known to restrict structural plasticity in the CNS. This provides a new mechanistic insight into how these interventions may enhance hippocampal-related plasticity and facilitate learning, memory, and neuroregeneration.

• MeSH
• hipokampus * metabolismus   MeSH
• hypoxie metabolismus   patofyziologie   MeSH
• kinázy asociované s rho * metabolismus   genetika   MeSH
• krysa rodu rattus MeSH
• mícha metabolismus   fyziologie   MeSH
• mozková kůra metabolismus   fyziologie   MeSH
• neuroplasticita fyziologie   MeSH
• potkani Wistar * MeSH
• rho proteiny vázající GTP MeSH
• rhoA protein vázající GTP metabolismus   MeSH
• signální transdukce * fyziologie   MeSH
• vysoce intenzivní intervalový trénink * MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Effective treatment of patients with autism spectrum disorder (ASD) is still absent so far. Taurine exhibits therapeutic effects towards the autism-like behaviour in ASD model animals. Here, we determined the mechanism of taurine effect on hippocampal neurogenesis in genetically inbred BTBR T+ tf/J (BTBR) mice, a proposed model of ASD. In this ASD mouse model, we explored the effect of oral taurine supplementation on ASD-like behaviours in an open field test, elevated plus maze, marble burying test, self-grooming test, and three-chamber test. The mice were divided into four groups of normal controls (WT) and models (BTBR), who did or did not receive 6-week taurine supplementation in water (WT, WT+ Taurine, BTBR, and BTBR+Taurine). Neurogenesis-related effects were determined by Ki67 immunofluorescence staining. Western blot analysis was performed to detect the expression of phosphatase and tensin homologue deleted from chromosome 10 (PTEN)/mTOR/AKT pathway-associated proteins. Our results showed that taurine improved the autism-like behaviour, increased the proliferation of hippocampal cells, promoted PTEN expression, and reduced phosphorylation of mTOR and AKT in hippocampal tissue of the BTBR mice. In conclusion, taurine reduced the autism-like behaviour in partially inherited autism model mice, which may be associa-ted with improving the defective neural precursor cell proliferation and enhancing the PTEN-associated pathway in hippocampal tissue.

• MeSH
• autistická porucha * metabolismus   farmakoterapie   MeSH
• chování zvířat účinky léků   MeSH
• fosfohydroláza PTEN * metabolismus   MeSH
• hipokampus * metabolismus   účinky léků   MeSH
• modely nemocí na zvířatech MeSH
• myši MeSH
• neurogeneze * účinky léků   MeSH
• poruchy autistického spektra metabolismus   farmakoterapie   MeSH
• proliferace buněk účinky léků   MeSH
• protoonkogenní proteiny c-akt * metabolismus   MeSH
• signální transdukce * účinky léků   MeSH
• taurin * farmakologie   MeSH
• TOR serin-threoninkinasy * metabolismus   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Exposure to lipopolysaccharide (LPS) during prenatal development leads to various changes in neurobiological and behavioural patterns. Similarly, continuous exposure to constant light (LL) during the critical developmental period of the circadian system affects gene expression in various tissues in adulthood. Given the reciprocal nature of the interaction between the circadian and the immune systems, our study primarily investigated the individual effects of both interventions and, more importantly, their combined effect. We aimed to explore whether there might be a potential synergistic effect on circadian rhythms and their parameters, focussing on the expression of clock genes, immune-related genes, and specific genes in the hippocampus, pineal gland, spleen and adrenal gland of rats at postnatal day 30. Our results show a significant influence of prenatal LPS and postnatal LL on the expression profiles of all genes assessed. However, the combination of prenatal LPS and postnatal LL only revealed an enhanced negative effect in a minority of the comparisons. In most cases, it appeared to attenuate the changes induced by the individual interventions, restoring the measured parameters to values closer to those of the control group. In particular, genes such as Nr1d1, Aanat and Tph1 showed increased amplitude in the pineal gland and spleen, while the kynurenine enzymes Kynu and KatII developed circadian rhythmicity in the adrenal glands only after the combined interventions. Our data suggest that a mild immunological challenge during prenatal development may play a critical role in triggering an adaptive response of the circadian clock later in life.

• MeSH
• cirkadiánní rytmus * fyziologie   MeSH
• epifýza mozková metabolismus   MeSH
• hipokampus metabolismus   MeSH
• krysa rodu rattus MeSH
• lipopolysacharidy * MeSH
• nadledviny metabolismus   MeSH
• potkani Wistar MeSH
• slezina * metabolismus   MeSH
• světlo * MeSH
• těhotenství MeSH
• transkriptom MeSH
• zpožděný efekt prenatální expozice * metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• těhotenství MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Throughout the brain, astrocytes form networks mediated by gap junction channels that promote the activity of neuronal ensembles. Although their inputs on neuronal information processing are well established, how molecular gap junction channels shape neuronal network patterns remains unclear. Here, using astroglial connexin-deficient mice, in which astrocytes are disconnected and neuronal bursting patterns are abnormal, we show that astrocyte networks strengthen bursting activity via dynamic regulation of extracellular potassium levels, independently of glutamate homeostasis or metabolic support. Using a facilitation-depression model, we identify neuronal afterhyperpolarization as the key parameter underlying bursting pattern regulation by extracellular potassium in mice with disconnected astrocytes. We confirm this prediction experimentally and reveal that astroglial network control of extracellular potassium sustains neuronal afterhyperpolarization via KCNQ voltage-gated K+ channels. Altogether, these data delineate how astroglial gap junctions mechanistically strengthen neuronal population bursts and point to approaches for controlling aberrant activity in neurological diseases.

• MeSH
• akční potenciály fyziologie   MeSH
• astrocyty * metabolismus   MeSH
• draslík * metabolismus   MeSH
• draslíkové kanály KCNQ * metabolismus   genetika   MeSH
• hipokampus * metabolismus   MeSH
• konexiny metabolismus   genetika   MeSH
• mezerový spoj * metabolismus   MeSH
• myši inbrední C57BL MeSH
• myši knockoutované MeSH
• myši MeSH
• nervová síť metabolismus   MeSH
• neurony metabolismus   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Fragile X syndrome (FXS) is an inherited form of intellectual disability caused by the loss of the mRNA-binding fragile X mental retardation protein (FMRP). FXS is characterized by neuronal hyperexcitability and behavioral defects, however the mechanisms underlying these critical dysfunctions remain unclear. Here, using male Fmr1 knockout mouse model of FXS, we identify abnormal extracellular potassium homeostasis, along with impaired potassium channel Kir4.1 expression and function in astrocytes. Further, we reveal that Kir4.1 mRNA is a binding target of FMRP. Finally, we show that the deficit in astroglial Kir4.1 underlies neuronal hyperexcitability and several behavioral defects in Fmr1 knockout mice. Viral delivery of Kir4.1 channels specifically to hippocampal astrocytes from Fmr1 knockout mice indeed rescues normal astrocyte potassium uptake, neuronal excitability, and cognitive and social performance. Our findings uncover an important role for astrocyte dysfunction in the pathophysiology of FXS, and identify Kir4.1 channel as a potential therapeutic target for FXS.

• MeSH
• astrocyty * metabolismus   MeSH
• chování zvířat MeSH
• draslík metabolismus   MeSH
• draslíkové kanály dovnitř usměrňující * metabolismus   genetika   MeSH
• hipokampus metabolismus   MeSH
• messenger RNA metabolismus   genetika   MeSH
• modely nemocí na zvířatech MeSH
• myši inbrední C57BL MeSH
• myši knockoutované MeSH
• myši MeSH
• neurony * metabolismus   fyziologie   MeSH
• protein FMRP * metabolismus   genetika   MeSH
• syndrom fragilního X * metabolismus   genetika   patofyziologie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH