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

Cannabinoid CB1 receptors have been shown to regulate wide array of functions ranging from homeostasis to the cognitive functioning but recent data support the hypothesis that astrocytes also operate as a mediator of synaptic plasticity and contribute to cognition and learning. The receptor heterogeneity plays a key role in understanding the molecular mechanisms underlying these processes. Despite the fact that the majority of CB1 receptors act on neurons, studies have revealed that cannabinoids have direct control over astrocytes, including energy generation and neuroprotection. The tripartite synapse connects astrocytes to neurons and allows them to interact with one another and the astrocytes are key players in synaptic plasticity, which is associated with cognitive functions. This review focuses on our growing understanding of the intricate functions of astroglial CB1 that underpin physiological brain function, and in Alzheimer's disease.

• MeSH
• Alzheimerova nemoc * MeSH
• astrocyty MeSH
• endokanabinoidy MeSH
• kognitivní dysfunkce * MeSH
• lidé MeSH
• neurony MeSH
• neuroplasticita fyziologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

All components of the CNS are surrounded by a diffuse extracellular matrix (ECM) containing chondroitin sulphate proteoglycans (CSPGs), heparan sulphate proteoglycans (HSPGs), hyaluronan, various glycoproteins including tenascins and thrombospondin, and many other molecules that are secreted into the ECM and bind to ECM components. In addition, some neurons, particularly inhibitory GABAergic parvalbumin-positive (PV) interneurons, are surrounded by a more condensed cartilage-like ECM called perineuronal nets (PNNs). PNNs surround the soma and proximal dendrites as net-like structures that surround the synapses. Attention has focused on the role of PNNs in the control of plasticity, but it is now clear that PNNs also play an important part in the modulation of memory. In this review we summarize the role of the ECM, particularly the PNNs, in the control of various types of memory and their participation in memory pathology. PNNs are now being considered as a target for the treatment of impaired memory. There are many potential treatment targets in PNNs, mainly through modulation of the sulphation, binding, and production of the various CSPGs that they contain or through digestion of their sulphated glycosaminoglycans.

• MeSH
• chondroitinsulfát proteoglykany * metabolismus   MeSH
• dendrity metabolismus   MeSH
• extracelulární matrix * metabolismus   MeSH
• neurony metabolismus   MeSH
• neuroplasticita fyziologie   MeSH
• synapse metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Research Support, N.I.H., Extramural MeSH

• Klíčová slova
• vzrušivost,
• MeSH
• lidé MeSH
• mozek anatomie a histologie   MeSH
• nervový přenos fyziologie   MeSH
• nervový systém - fyziologické jevy MeSH
• neurobiologie * MeSH
• neurony cytologie   fyziologie   MeSH
• neuroplasticita MeSH
• neurotransmiterové látky farmakologie   fyziologie   klasifikace   MeSH
• synapse fyziologie   MeSH
• terminologie jako téma * MeSH
• Check Tag
• lidé MeSH

Regulation of axon guidance and pruning of inappropriate synapses by class 3 semaphorins are key to the development of neural circuits. Collapsin response mediator protein 2 (CRMP2) has been shown to regulate axon guidance by mediating semaphorin 3A (Sema3A) signaling; however, nothing is known about its role in synapse pruning. Here, using newly generated crmp2-/- mice we demonstrate that CRMP2 has a moderate effect on Sema3A-dependent axon guidance in vivo, and its deficiency leads to a mild defect in axon guidance in peripheral nerves and the corpus callosum. Surprisingly, crmp2-/- mice display prominent defects in stereotyped axon pruning in hippocampus and visual cortex and altered dendritic spine remodeling, which is consistent with impaired Sema3F signaling and with models of autism spectrum disorder (ASD). We demonstrate that CRMP2 mediates Sema3F signaling in primary neurons and that crmp2-/- mice display ASD-related social behavior changes in the early postnatal period as well as in adults. Together, we demonstrate that CRMP2 mediates Sema3F-dependent synapse pruning and its dysfunction shares histological and behavioral features of ASD.

• MeSH
• dendritické trny MeSH
• membránové proteiny fyziologie   MeSH
• mezibuněčné signální peptidy a proteiny genetika   MeSH
• myši knockoutované MeSH
• myši MeSH
• neurony MeSH
• neuroplasticita MeSH
• poruchy autistického spektra * MeSH
• proteiny nervové tkáně genetika   fyziologie   MeSH
• semaforiny * MeSH
• signální transdukce MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The perineuronal net (PNN) is a mesh-like proteoglycan structure on the neuronal surface which is involved in regulating plasticity. The PNN regulates plasticity via multiple pathways, one of which is direct regulation of synapses through the control of AMPA receptor mobility. Since neuronal pentraxin 2 (Nptx2) is a known regulator of AMPA receptor mobility and Nptx2 can be removed from the neuronal surface by PNN removal, we investigated whether Nptx2 has a function in the PNN. We found that Nptx2 binds to the glycosaminoglycans hyaluronan and chondroitin sulphate E in the PNN. Furthermore, in primary cortical neuron cultures, the addition of NPTX2 to the culture medium enhances PNN formation during PNN development. These findings suggest Nptx2 as a novel PNN binding protein with a role in the mechanism of PNN formation.

• MeSH
• C-reaktivní protein metabolismus   MeSH
• krysa rodu rattus MeSH
• kultivované buňky MeSH
• nervová síť chemie   cytologie   metabolismus   MeSH
• neurony chemie   metabolismus   MeSH
• neuroplasticita fyziologie   MeSH
• perineuronální satelitní buňky chemie   metabolismus   MeSH
• potkani Sprague-Dawley MeSH
• proteiny nervové tkáně metabolismus   MeSH
• vazba proteinů fyziologie   MeSH
• zrakové korové centrum chemie   cytologie   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

In neural computation, the essential information is generally encoded into the neurons via their spiking configurations, activation values or (attractor) dynamics. The synapses and their associated plasticity mechanisms are, by contrast, mainly used to process this information and implement the crucial learning features. Here, we propose a novel Turing complete paradigm of neural computation where the essential information is encoded into discrete synaptic states, and the updating of this information achieved via synaptic plasticity mechanisms. More specifically, we prove that any 2-counter machine-and hence any Turing machine-can be simulated by a rational-weighted recurrent neural network employing spike-timing-dependent plasticity (STDP) rules. The computational states and counter values of the machine are encoded into discrete synaptic strengths. The transitions between those synaptic weights are then achieved via STDP. These considerations show that a Turing complete synaptic-based paradigm of neural computation is theoretically possible and potentially exploitable. They support the idea that synapses are not only crucially involved in information processing and learning features, but also in the encoding of essential information. This approach represents a paradigm shift in the field of neural computation.

• MeSH
• algoritmy MeSH
• modely neurologické * MeSH
• neuronové sítě MeSH
• neurony fyziologie   MeSH
• neuroplasticita * MeSH
• synapse fyziologie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH

Fragile X syndrome (FXS) is the most frequently inherited form of intellectual disability and prevalent single-gene cause of autism. A priority of FXS research is to determine the molecular mechanisms underlying the cognitive and social functioning impairments in humans and the FXS mouse model. Glutamate ionotropic alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors (AMPARs) mediate a majority of fast excitatory neurotransmission in the central nervous system and are critically important for nearly all aspects of brain function, including neuronal development, synaptic plasticity, and learning and memory. Both preclinical and clinical studies have indicated that expression, trafficking, and functions of AMPARs are altered and result in altered synapse development and plasticity, cognitive impairment, and poor mental health in FXS. In this review, we discuss the contribution of AMPARs to disorders of FXS by highlighting recent research advances with a specific focus on change in AMPARs expression, trafficking, and dependent synaptic plasticity. Since changes in synaptic strength underlie the basis of learning, development, and disease, we suggest that the current knowledge base of AMPARs has reached a unique point to permit a comprehensive re-evaluation of their roles in FXS.

• MeSH
• AMPA receptory genetika   metabolismus   MeSH
• lidé MeSH
• mentální retardace genetika   metabolismus   MeSH
• mutace fyziologie   MeSH
• neuroplasticita fyziologie   MeSH
• syndrom fragilního X genetika   metabolismus   MeSH
• transport proteinů fyziologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Hippocampal place cells represent different environments with distinct neural activity patterns. Following an abrupt switch between two familiar configurations of visual cues defining two environments, the hippocampal neural activity pattern switches almost immediately to the corresponding representation. Surprisingly, during a transient period following the switch to the new environment, occasional fast transitions between the two activity patterns (flickering) were observed (Jezek, Henriksen, Treves, Moser, & Moser, ). Here we show that an attractor neural network model of place cells with connections endowed with short-term synaptic plasticity can account for this phenomenon. A memory trace of the recent history of network activity is maintained in the state of the synapses, allowing the network to temporarily reactivate the representation of the previous environment in the absence of the corresponding sensory cues. The model predicts that the number of flickering events depends on the amplitude of the ongoing theta rhythm and the distance between the current position of the animal and its position at the time of cue switching. We test these predictions with new analysis of experimental data. These results suggest a potential role of short-term synaptic plasticity in recruiting the activity of different cell assemblies and in shaping hippocampal activity of behaving animals.

• MeSH
• akční potenciály fyziologie   MeSH
• časové faktory MeSH
• elektroencefalografie MeSH
• hipokampus cytologie   MeSH
• krysa rodu rattus MeSH
• mapování mozku MeSH
• modely neurologické * MeSH
• nervová síť fyziologie   MeSH
• neurony fyziologie   MeSH
• neuroplasticita fyziologie   MeSH
• podněty MeSH
• prostorová paměť fyziologie   MeSH
• světelná stimulace MeSH
• theta rytmus EEG fyziologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

• Klíčová slova
• synaptogeneze,
• MeSH
• anestetika disociativní farmakologie   škodlivé účinky   terapeutické užití   MeSH
• antagonisté excitačních aminokyselin farmakologie   škodlivé účinky   terapeutické užití   MeSH
• antidepresiva farmakologie   škodlivé účinky   terapeutické užití   MeSH
• bipolární porucha farmakoterapie   MeSH
• celková anestezie MeSH
• deprese nereagující na léčbu farmakoterapie   MeSH
• depresivní porucha unipolární farmakoterapie   MeSH
• depresivní poruchy * farmakoterapie   MeSH
• ketamin * farmakologie   škodlivé účinky   terapeutické užití   MeSH
• lidé MeSH
• mozkový neurotrofický faktor účinky léků   MeSH
• neuroplasticita * účinky léků   MeSH
• receptory N-methyl-D-aspartátu účinky léků   MeSH
• sebevražedné myšlenky MeSH
• synapse účinky léků   MeSH
• TOR serin-threoninkinasy MeSH
• způsoby aplikace léků MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• práce podpořená grantem MeSH
• přehledy MeSH