scholarly journals Insulin modulates hippocampal activity-dependent synaptic plasticity in a N-methyl-d-aspartate receptor and phosphatidyl-inositol-3-kinase-dependent manner

2005 ◽  
Vol 94 (4) ◽  
pp. 1158-1166 ◽  
Author(s):  
Lars P. Van Der Heide ◽  
Amer Kamal ◽  
Alain Artola ◽  
Willem Hendrik Gispen ◽  
Geert M. J. Ramakers
Keyword(s):  
Synaptic Plasticity ◽  
Phosphatidyl Inositol ◽  
Dependent Manner ◽  
Aspartate Receptor ◽  
Hippocampal Activity ◽  
Activity Dependent

scholarly journals Synaptic control of DNA methylation involves activity-dependent degradation of DNMT3A1 in the nucleus

2020 ◽  
Vol 45 (12) ◽  
pp. 2120-2130 ◽  
Author(s):  
Gonca Bayraktar ◽  
PingAn Yuanxiang ◽  
Alessandro D. Confettura ◽  
Guilherme M. Gomes ◽  
Syed A. Raza ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Synaptic Plasticity ◽  
Promoter Methylation ◽  
Dna Methyltransferase ◽  
De Novo ◽  
Memory Formation ◽  
Epigenetic Mark ◽  
Dependent Manner ◽  
Synaptic Control ◽  
Activity Dependent

Abstract DNA methylation is a crucial epigenetic mark for activity-dependent gene expression in neurons. Very little is known about how synaptic signals impact promoter methylation in neuronal nuclei. In this study we show that protein levels of the principal de novo DNA-methyltransferase in neurons, DNMT3A1, are tightly controlled by activation of N-methyl-D-aspartate receptors (NMDAR) containing the GluN2A subunit. Interestingly, synaptic NMDARs drive degradation of the methyltransferase in a neddylation-dependent manner. Inhibition of neddylation, the conjugation of the small ubiquitin-like protein NEDD8 to lysine residues, interrupts degradation of DNMT3A1. This results in deficits in promoter methylation of activity-dependent genes, as well as synaptic plasticity and memory formation. In turn, the underlying molecular pathway is triggered by the induction of synaptic plasticity and in response to object location learning. Collectively, the data show that plasticity-relevant signals from GluN2A-containing NMDARs control activity-dependent DNA-methylation involved in memory formation.

scholarly journals Modulation of Synaptic Plasticity by Glutamatergic Gliotransmission: A Modeling Study

2016 ◽  
Vol 2016 ◽  
pp. 1-30 ◽  
Author(s):  
Maurizio De Pittà ◽  
Nicolas Brunel
Keyword(s):  
Synaptic Plasticity ◽  
Glutamate Release ◽  
Spike Timing ◽  
Biophysical Model ◽  
Dependent Manner ◽  
Inward Currents ◽  
Functional Relevance ◽  
And Function ◽  
Activity Dependent

Glutamatergic gliotransmission, that is, the release of glutamate from perisynaptic astrocyte processes in an activity-dependent manner, has emerged as a potentially crucial signaling pathway for regulation of synaptic plasticity, yet its modes of expression and function in vivo remain unclear. Here, we focus on two experimentally well-identified gliotransmitter pathways, (i) modulations of synaptic release and (ii) postsynaptic slow inward currents mediated by glutamate released from astrocytes, and investigate their possible functional relevance on synaptic plasticity in a biophysical model of an astrocyte-regulated synapse. Our model predicts that both pathways could profoundly affect both short- and long-term plasticity. In particular, activity-dependent glutamate release from astrocytes could dramatically change spike-timing-dependent plasticity, turning potentiation into depression (and vice versa) for the same induction protocol.

scholarly journals BACE1 Is Necessary for Experience-Dependent Homeostatic Synaptic Plasticity in Visual Cortex

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Emily Petrus ◽  
Hey-Kyoung Lee
Keyword(s):  
Synaptic Plasticity ◽  
Visual Cortex ◽  
Synaptic Transmission ◽  
Sensory Experience ◽  
Synaptic Function ◽  
Excitatory Synaptic Transmission ◽  
Early Gene ◽  
Dependent Manner ◽  
Homeostatic Synaptic Plasticity ◽  
Activity Dependent

Alzheimer’s disease (AD) is the most common form of age-related dementia, which is thought to result from overproduction and/or reduced clearance of amyloid-beta (Aβ) peptides. Studies over the past few decades suggest that Aβis produced in an activity-dependent manner and has physiological relevance to normal brain functions. Similarly, physiological functions forβ- andγ-secretases, the two key enzymes that produce Aβby sequentially processing the amyloid precursor protein (APP), have been discovered over recent years. In particular, activity-dependent production of Aβhas been suggested to play a role in homeostatic regulation of excitatory synaptic function. There is accumulating evidence that activity-dependent immediate early gene Arc is an activity “sensor,” which acts upstream of Aβproduction and triggers AMPA receptor endocytosis to homeostatically downregulate the strength of excitatory synaptic transmission. We previously reported that Arc is critical for sensory experience-dependent homeostatic reduction of excitatory synaptic transmission in the superficial layers of visual cortex. Here we demonstrate that mice lacking the major neuronalβ-secretase, BACE1, exhibit a similar phenotype: stronger basal excitatory synaptic transmission and failure to adapt to changes in visual experience. Our results indicate that BACE1 plays an essential role in sensory experience-dependent homeostatic synaptic plasticity in the neocortex.

scholarly journals SUSD4 Controls Activity-Dependent Degradation of AMPA Receptor GLUA2 and Synaptic Plasticity

2019 ◽  
Author(s):  
I. González-Calvo ◽  
K. Iyer ◽  
M. Carquin ◽  
A. Khayachi ◽  
F.A. Giuliani ◽  
...  
Keyword(s):  
Synaptic Plasticity ◽  
Ampa Receptor ◽  
Ampa Receptors ◽  
Motor Coordination ◽  
Transmembrane Protein ◽  
Ubiquitin Ligases ◽  
Potential Contribution ◽  
Dependent Manner ◽  
Activity Dependent

SummaryAt excitatory synapses, the choice between recycling or degradation of glutamate AMPA receptors controls the direction of synaptic plasticity. In this context, how the degradation machinery is targeted to specific synaptic substrates in an activity-dependent manner is not understood. Here we show that SUSD4, a complement-related transmembrane protein, is a tether for HECT ubiquitin ligases of the NEDD4 subfamily, which promote the degradation of a large number of cellular substrates. SUSD4 is expressed by many neuronal populations starting at the time of synapse formation. Loss-of-function of Susd4 in the mouse prevents activity-dependent degradation of the GLUA2 AMPA receptor subunit and long-term depression at cerebellar synapses, and leads to impairment in motor coordination adaptation and learning. SUSD4 could thus act as an adaptor targeting NEDD4 ubiquitin ligases to AMPA receptors during long-term synaptic plasticity. These findings shed light on the potential contribution of SUSD4 mutations to the etiology of neurodevelopmental diseases.

scholarly journals Synaptic control of DNA-methylation involves activity-dependent degradation of DNMT3a1 in the nucleus

2019 ◽  
Author(s):  
Gonca Bayraktar ◽  
PingAn Yuanxiang ◽  
Guilherme M Gomes ◽  
Aessandro D Confettura ◽  
Syed A Raza ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Synaptic Plasticity ◽  
Promoter Methylation ◽  
Dna Methyltransferase ◽  
De Novo ◽  
Memory Formation ◽  
Epigenetic Mark ◽  
Dependent Manner ◽  
Synaptic Control ◽  
Activity Dependent

AbstractDNA-methylation is a crucial epigenetic mark for activity-dependent gene expression in neurons. Very little is known how synaptic signals impact promoter methylation in neuronal nuclei. In this study we show that protein levels of the principal de novo DNA-methyltransferase in neurons, DNMT3a1, are tightly controlled by activation of N-methyl-D-aspartate receptors (NMDAR) containing the GluN2A subunit. Interestingly, synaptic NMDAR drive degradation of the methyltransferase in a neddylation-dependent manner. Inhibition of neddylation, the conjugation of the small ubiquitin-like protein NEDD8 to lysine residues, interrupts degradation of DNMT3a1 and results in deficits of promoter methylation of activity-dependent genes, synaptic plasticity as well as memory formation. In turn, the underlying molecular pathway is triggered by the induction of synaptic plasticity and in response to object location learning. Collectively the data show that GluN2A containing NMDAR control synapse-to-nucleus signaling that links plasticity-relevant signals to activity-dependent DNA-methylation involved in memory formation.

scholarly journals An activity-dependent local transport regulation via degradation and synthesis of KIF17 underlying cognitive flexibility

2020 ◽  
Vol 6 (51) ◽  
pp. eabc8355
Author(s):  
Suguru Iwata ◽  
Momo Morikawa ◽  
Yosuke Takei ◽  
Nobutaka Hirokawa
Keyword(s):  
Cognitive Flexibility ◽  
Molecular Motor ◽  
Fear Memory ◽  
Dependent Manner ◽  
Weight Changes ◽  
Regulatory Processes ◽  
Aspartate Receptor ◽  
Local Transport ◽  
Activity Dependent ◽  
Specific Deletion

Synaptic weight changes among postsynaptic densities within a single dendrite are regulated by the balance between localized protein degradation and synthesis. However, the molecular mechanism via these opposing regulatory processes is still elusive. Here, we showed that the molecular motor KIF17 was locally degraded and synthesized in an N-methyl-d-aspartate receptor (NMDAR)–mediated activity–dependent manner. Accompanied by the degradation of KIF17, its transport was temporarily dampened in dendrites. We also observed that activity-dependent local KIF17 synthesis driven by its 3′ untranslated region (3′UTR) occurred at dendritic shafts, and the newly synthesized KIF17 moved along the dendrites. Furthermore, hippocampus-specific deletion of Kif17 3′UTR disrupted KIF17 synthesis induced by fear memory retrieval, leading to impairment in extinction of fear memory. These results indicate that the regulation of the KIF17 transport is driven by the single dendrite–restricted cycle of degradation and synthesis that underlies cognitive flexibility.

scholarly journals Local autocrine signaling of IGF1 synthesized and released by CA1 pyramidal neurons regulates plasticity of dendritic spines

2021 ◽  
Author(s):  
Xun Tu ◽  
Anant Jain ◽  
Helena Decker ◽  
Ryohei Yasuda
Keyword(s):  
Synaptic Plasticity ◽  
Dendritic Spines ◽  
Pyramidal Neurons ◽  
Receptor Activation ◽  
Brain Regions ◽  
Dependent Manner ◽  
Autocrine Signaling ◽  
Ca1 Pyramidal Neurons ◽  
Igf1 Receptor ◽  
Activity Dependent

Insulin-like growth factor 1 (IGF1) regulates hippocampal plasticity, learning, and memory. While circulating, liver-derived IGF1 is known to play an essential role in hippocampal function and plasticity, IGF1 is also synthesized in multiple brain regions, including the hippocampus. However, little is known about the role of hippocampus-derived IGF1 in synaptic plasticity, the type of cells that may provide relevant IGF1, and the spatiotemporal dynamics of IGF1 signaling. Here, using a new FRET sensor for IGF1 signaling, we show that IGF1 in the hippocampus is primarily synthesized in CA1 pyramidal neurons and released in an activity-dependent manner in mice. The local IGF1 release from dendritic spines triggers local autocrine IGF1 receptor activation on the same spine, regulating structural and electrophysiological plasticity of the activated spine. Thus, our study demonstrates a novel mechanism underlying synaptic plasticity by the synthesis and autocrine signaling of IGF1 specific to CA1 pyramidal neurons.

scholarly journals Dynamic Regulation of NMDA Receptor Transmission

2011 ◽  
Vol 105 (1) ◽  
pp. 162-171 ◽  
Author(s):  
Abigail C. Gambrill ◽  
Granville P. Storey ◽  
Andres Barria
Keyword(s):  
Synaptic Plasticity ◽  
Low Frequency ◽  
Long Term Potentiation ◽  
Synaptic Activity ◽  
Dependent Manner ◽  
Dynamic Regulation ◽  
Low Frequency Stimulation ◽  
Term Potentiation ◽  
Frequency Stimulation ◽  
Activity Dependent

N-methyl-d-aspartate receptors (NMDARs) are critical for establishing, maintaining, and modifying glutamatergic synapses in an activity-dependent manner. The subunit composition, synaptic expression, and some of the properties of NMDARs are regulated by synaptic activity, affecting processes like synaptic plasticity. NMDAR transmission is dynamic, and we were interested in studying the effect of acute low or null synaptic activity on NMDA receptors and its implications for synaptic plasticity. Periods of no stimulation or low-frequency stimulation increased NMDAR transmission. Changes became stable after periods of 20 min of low or no stimulation. These changes in transmission have a postsynaptic origin and are explained by incorporation of GluN2B-containing receptors to synapses. Importantly, periods of low or no stimulation facilitate long-term potentiation induction. Moreover, recovery after a weak preconditioning stimulus that normally blocks subsequent potentiation is facilitated by a nonstimulation period. Thus synaptic activity dynamically regulates the level of NMDAR transmission adapting constantly the threshold for plasticity.

scholarly journals Neural Circuitry–Neurogenesis Coupling Model of Depression

2021 ◽  
Vol 22 (5) ◽  
pp. 2468
Author(s):  
Il Bin Kim ◽  
Seon-Cheol Park
Keyword(s):  
Entorhinal Cortex ◽  
Coupling Model ◽  
Neural Circuitry ◽  
Hippocampal Neurogenesis ◽  
Pattern Separation ◽  
Dependent Process ◽  
Hippocampal Activity ◽  
Mechanistic Understanding ◽  
Activity Dependent ◽  
Memory Pattern

Depression is characterized by the disruption of both neural circuitry and neurogenesis. Defects in hippocampal activity and volume, indicative of reduced neurogenesis, are associated with depression-related behaviors in both humans and animals. Neurogenesis in adulthood is considered an activity-dependent process; therefore, hippocampal neurogenesis defects in depression can be a result of defective neural circuitry activity. However, the mechanistic understanding of how defective neural circuitry can induce neurogenesis defects in depression remains unclear. This review highlights the current findings supporting the neural circuitry-regulated neurogenesis, especially focusing on hippocampal neurogenesis regulated by the entorhinal cortex, with regard to memory, pattern separation, and mood. Taken together, these findings may pave the way for future progress in neural circuitry–neurogenesis coupling studies of depression.

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