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Two experiments examined the effect of the noncompetitive NMDA receptor antagonist, dizocilpine maleate (MK-801), on spatial working memory during development. Rats were trained on spatial delayed alternation (SDA) in a T-maze after ip administration of 0.06 mg/kg MK-801, 0.1 mg/kg MK-801, or saline on postnatal days (P) P23 and P33 (Experiment 1), or following bilateral intrahippocampal administration of 2.5 or 5.0 microg per side MK-801 or saline on P26 (Experiment 2). In Experiment 1, MK-801 dose-dependently impaired SDA learning at both ages. Because the same doses of systemic MK-801 have no effect on T-maze position discrimination learning, impairment of SDA by MK-801 likely reflects disruption of spatial working memory. Both doses of MK-801 abolished acquisition of SDA performance in Experiment 2. Disruption of hippocampal plasticity may account for the effects produced by systemic MK-801 administration. These results confirm and extend earlier lesion studies by implicating plasticity of hippocampal neurons in the ontogeny of spatial delayed alternation.
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http://dx.doi.org/10.1037/a0013633 | DOI Listing |
Transl Stroke Res
September 2025
Department of Radiology, Huashan Hospital, Fudan University, Shanghai, China.
Recent studies have shown that the glymphatic system plays a crucial role in driving hyperacute edema after ischemic stroke. This has sparked interest in understanding how this system changes in later phases of ischemic stroke. In this study, we utilized cisternal contrast-enhanced magnetic resonance imaging (CE-MRI) and immunofluorescence staining to investigate glymphatic system alterations at subacute and chronic phases of ischemic stroke.
View Article and Find Full Text PDFJ Magn Reson Imaging
September 2025
School of Biomedical Engineering, Guangdong Provincial Key Laboratory of Medical Image Processing and Guangdong Province Engineering Laboratory for Medical Imaging and Diagnostic Technology, Southern Medical University, Guangzhou, China.
Background: The dynamic progression of gray matter (GM) microstructural alterations following radiotherapy (RT) in patients, and the relationship between these microstructural abnormalities and cortical morphometric changes remains unclear.
Purpose: To longitudinally characterize RT-related GM microstructural changes and assess their potential causal links with classic morphometric alterations in patients with nasopharyngeal carcinoma (NPC).
Study Type: Prospective, longitudinal.
Front Plant Sci
August 2025
Country College of Soil and Water Conservation Science and Engineering, Northwest A&F University, Xianyang, Shaanxi, China.
Introduction: The discrepancies in near-soil-surface hydrologic processes triggered by herbage spatial distribution pattern greatly influence the variation in hillslope erosion process. However, knowledge about the influence of herbage spatial distribution pattern on hillslope erosion is still limited.
Methods: In the current study, runoff plots (length × width × depth, 2 × 1 × 0.
J Environ Manage
September 2025
College of Hydraulic and Civil Engineering, Xinjiang Agricultural University, Urumqi, 830052, China; Xinjiang Key Laboratory of Hydraulic Engineering Security and Water Disasters Prevention, Urumqi, 830052, China. Electronic address:
Drought is one of the most destructive natural disasters globally. Understanding its propagation mechanisms and the causal relationships among different drought types is crucial for effective monitoring and mitigation. Using meteorological (SPI), hydrological (SRI), and agricultural (SSMI) drought indices from 1983 to 2023 in Xinjiang, this study employs the Convergent Cross Mapping (CCM) method to systematically quantify nonlinear causal relationships among the three drought types, revealing their temporal lag characteristics, spatial heterogeneity, and multiscale dynamics.
View Article and Find Full Text PDFJ Phys Chem B
September 2025
National Key Laboratory of Solid Rocket Propulsion, Northwestern Polytechnical University, Xi'an 710072, China.
Hexaazaisowurtzitane (CL-20) is a high-energy-density compound with poor thermal stability, which hinders its application in composite energetic systems. A bi-interface structure of polydopamine-coated graphene oxide (GO@PDA) is shown to markedly improve thermal stability compared with pristine CL-20 and single-layer coatings. Reactive molecular dynamics simulations enhanced by a neural network potential (NNP) reveal that the delayed onset of decomposition arises from suppressed NO release and altered spatial density distribution, while interfacial -OH and -COOH groups consume intermediates, redirect decomposition pathways, and inhibit autocatalytic chain reactions.
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