Acidic organelles, such as endosomes and lysosomes, store Ca that is released in response to intracellular increases in the second messenger nicotinic acid adenine dinucleotide phosphate (NAADP). In neurons, NAADP and Ca signaling contribute to synaptic plasticity, a process of activity-dependent long-term potentiation (LTP) [or, alternatively, long-term depression (LTD)] of synaptic strength and neuronal transmission that is critical for neuronal function and memory formation. We explored the function of and mechanisms regulating acidic Ca store signaling in murine hippocampal neurons. We found that metabotropic glutamate receptor 1 (mGluR1) was coupled to NAADP signaling that elicited Ca release from acidic stores. In turn, this released Ca-mediated mGluR1-dependent LTP by transiently inhibiting SK-type K channels, possibly through the activation of protein phosphatase 2A. Genetically removing two-pore channels (TPCs), which are endolysosomal-specific ion channels, switched the polarity of plasticity from LTP to LTD, indicating the importance of specific receptor store coupling and providing mechanistic insight into how mGluR1 can produce both synaptic potentiation and synaptic depression.
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http://dx.doi.org/10.1126/scisignal.aat9093 | DOI Listing |
Sci Rep
January 2025
Department of Histology and Embryology, Ankara University School of Medicine, Ankara, Turkey.
NMDAR antagonists, such as memantine and ketamine, have shown efficacy in treating neurodegenerative diseases and major depression. The mechanism by which these drugs correct the aforementioned diseases is still unknown. Our study reveals that these antagonists significantly enhance 20S proteasome activity, crucial for degrading intrinsically disordered, oxidatively damaged, or misfolded proteins, factors pivotal in neurodegenerative diseases like Alzheimer's and Parkinson's.
View Article and Find Full Text PDFTransl Psychiatry
January 2025
Xiamen Key Laboratory of Brain Center, The First Affiliated Hospital of Xiamen University, and Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, Fujian, 361102, China.
Long-term potentiation (LTP) and long-term depression (LTD) are widely used to study synaptic plasticity. However, whether proteins regulating LTP and LTD are altered in cognitive disorders and contribute to disease onset remains to be determined. Herein, we induced LTP and LTD in the hippocampal CA3-CA1 Schaffer collateral pathway, respectively, and then performed proteomic analysis of the CA1 region.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Department of Neurophysiology, Medical Faculty, Ruhr University Bochum, Bochum 44780, Germany.
The novelty, saliency, and valency of ongoing experiences potently influence the firing rate of the ventral tegmental area (VTA) and the locus coeruleus (LC). Associative experience, in turn, is recorded into memory by means of hippocampal synaptic plasticity that is regulated by noradrenaline sourced from the LC, and dopamine, sourced from both the VTA and LC. Two persistent forms of synaptic plasticity, long-term potentiation (LTP), and long-term depression (LTD) support the encoding of different kinds of spatial experience.
View Article and Find Full Text PDFJACC Heart Fail
January 2025
Department of Medicine, University of Mississippi Medical Center, Jackson, Mississippi, USA; Baylor Scott and White Research Institute, Baylor Scott and White Health, Dallas, Texas, USA. Electronic address:
Several trials have evaluated diuretic-based strategies to improve symptoms and outcomes in patients with acute heart failure (AHF). The authors sought to summarize the effect of different combination strategies on symptoms, physical signs, physiological variables, and outcomes in patients with AHF. Twelve trials were identified that assessed the addition of thiazide diuretics, sodium-glucose cotransporter 2 inhibitors, mineralocorticoid receptor antagonists, vasopressin receptor antagonists, carbonic anhydrase inhibitors, or loop diuretic intensification to conventional therapy for AHF.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Center for Neuroscience, University of California, Davis, CA 95618.
How newly formed memories are preserved while brain plasticity is ongoing has been a source of debate. One idea is that synapses which experienced recent plasticity become resistant to further plasticity, a type of metaplasticity often referred to as saturation. Here, we probe the local dendritic mechanisms that limit plasticity at recently potentiated synapses.
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