Protein posttranslational modification regulates synaptic protein stability, sorting and trafficking, and is involved in emotional disorders. Yet the molecular mechanisms regulating emotional disorders remain unelucidated. Here we report unknown roles of protein palmitoylation/nitrosylation crosstalk in regulating anxiety-like behaviors in rats.
View Article and Find Full Text PDFAims: The autophagy-lysosomal pathway is important for maintaining cellular proteostasis, while dysfunction of this pathway has been suggested to drive the aberrant intraneuronal accumulation of tau protein, leading to synaptic damage and cognitive impairment. Previous studies have demonstrated that the activation of transient receptor potential vanilloid 1 (TRPV1) by capsaicin has a positive impact on cognition and AD-related biomarkers. However, the effect and mechanism of TPRV1 activation on neuronal tau homeostasis remain elusive.
View Article and Find Full Text PDFFront Mol Neurosci
January 2023
Neurosci Bull
September 2023
Brain size abnormality is correlated with an increased frequency of autism spectrum disorder (ASD) in offspring. Genetic analysis indicates that heterozygous mutations of the WD repeat domain 62 (WDR62) are associated with ASD. However, biological evidence is still lacking.
View Article and Find Full Text PDFActivation of postsynaptic GABA-B receptors enhances tonic inhibition mediated by high-affinity extrasynaptic GABA receptors in dentate gyrus granule cells (DGGCs), thalamocortical neurons, and cerebellar granule cells. We investigated the mechanism(s) of GABA current modulation by GABA receptors in DGGCs using a combination of electrophysiological and biochemical approaches. In acute hippocampal brain slices the GABA receptor agonist baclofen increased GABA-evoked currents in ∼2/3rds of DGGCs, significantly increasing GABA currents by 41% on average.
View Article and Find Full Text PDFLong-term potentiation (LTP) is arguably the most compelling cellular model for learning and memory. While the mechanisms underlying the induction of LTP ('learning') are well understood, the maintenance of LTP ('memory') has remained contentious over the last 20 years. Here, we find that Ca-calmodulin-dependent kinase II (CaMKII) contributes to synaptic transmission and is required LTP maintenance.
View Article and Find Full Text PDFIonotropic glutamate delta receptors do not bind glutamate and do not generate ionic current, resulting in difficulty in studying the function and trafficking of these receptors. Here, we utilize chimeric constructs, in which the ligand-binding domain of GluD1 is replaced by that of GluK1, to examine its synaptic trafficking and plasticity. GluD1 trafficked to the synapse, but was incapable of expressing long-term potentiation (LTP).
View Article and Find Full Text PDFKainate-type glutamate receptors play critical roles in excitatory synaptic transmission and synaptic plasticity in the brain. GluK1 and GluK2 possess fundamentally different capabilities in surface trafficking as well as synaptic targeting in hippocampal CA1 neurons. Here we find that the excitatory postsynaptic currents (EPSCs) are significantly increased by the chimeric GluK1(SP) receptor, in which the signal peptide of GluK1 is replaced with that of GluK2.
View Article and Find Full Text PDFThe δ1 glutamate receptor (GluD1) was cloned decades ago and is widely expressed in many regions of the brain. However, its functional roles in these brain circuits remain unclear. Here, we find that GluD1 is required for both excitatory synapse formation and maintenance in the hippocampus.
View Article and Find Full Text PDFLong-term potentiation (LTP) is a persistent strengthening of synaptic transmission in the brain and is arguably the most compelling cellular and molecular model for learning and memory. Previous work found that both AMPA receptors and exogenously expressed kainate receptors are equally capable of expressing LTP, despite their limited homology and their association with distinct auxiliary subunits, indicating that LTP is far more promiscuous than previously thought. What might these two subtypes of glutamate receptor have in common? Using a single-cell molecular replacement strategy, we demonstrate that the AMPA receptor auxiliary subunit TARP γ-8, via its PDZ-binding motif, is indispensable for both basal synaptic transmission and LTP.
View Article and Find Full Text PDFAmbient GABA in the brain tonically activates extrasynaptic GABA(A) receptors, and activity-dependent changes in ambient GABA concentration can also activate GABA(B) receptors. To investigate an interaction between postsynaptic GABA(B) and GABA(A) receptors, we recorded GABA(A) currents elicited by exogenous GABA (10 μm) from dentate gyrus granule cells (DGGCs) in adult rat hippocampal slices. The GABA(B) receptor agonist baclofen (20 μm) enhanced GABA(A) currents.
View Article and Find Full Text PDFSubacute and chronic changes in tonic GABAergic inhibition occur in human and experimental epilepsy. Less is known about how tonic inhibition is modulated over shorter time frames (seconds). We measured endogenous tonic GABA currents from cultured rat hippocampal neurons to evaluate how they are affected by 1) transient increases in extracellular GABA concentration ([GABA]), 2) transient postsynaptic depolarization, and 3) depolarization of presynaptic cells.
View Article and Find Full Text PDFSeamoth (Pegasus laternarius Cuvier) is extensively used to treat various diseases on the coastland of Guangdong Province in China, such as scrofula, cough, and diarrhea. The total extract of Pegasus laternarius (EP) was subjected to column chromatography to acquire three different constituents (EPC1, EPC2, and EPC3). Cerebral neuron injury was induced by glutamate, H₂O₂, and serum deprivation.
View Article and Find Full Text PDFThe fruit hull of Garcinia mangostana L. contains oxygenated and prenylated phenol derivatives, such as xanthones or xanthen-9H-ones, and is used by people in Southeast Asia as a traditional medicine for the treatment of abdominal pain, dysentery, wound infections, suppuration, and chronic ulcer. We isolated the active ingredients from the crude ethanol extract of G.
View Article and Find Full Text PDFThe developmental changes of the sodium channel and construction of synapse connection were studied in cerebral cortical pyramidal neurons of rats at different age groups. We used whole-cell patch-clamp recordings to characterize electrophysiological properties of cortical neurons at different age stages, including the sodium currents, APs evoked by depolarizing current and short-term plasticity of the eEPSCs. The result shows that the sodium currents undergo a hyperpolarizing shift in activation process and acceleration of activation and inactivation with age.
View Article and Find Full Text PDFWe have investigated the action of the recombinant neurotoxins, named Hk7a and Hk2a, whose amino acid sequences differ only in two positions, isolated from the sea anemone Anthopleura sp., on neuronal sodium currents using the whole-cell voltage-clamp techniques. The rat cerebral cortical neurons in primary culture were used for this study.
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