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Nitric oxide (NO)-dependent pathways may play a significant role in the decline of synaptic and cognitive functions in Alzheimer's disease (AD). However, whether NO in the hippocampal dentate gyrus (DG) is involved in the spatial learning and memory impairments of AD by affecting the glutamate (Glu) response during these processes is not well-understood. Here, we prepared an AD rat model by long-term i.p. of D-galactose into ovariectomized rats, and then the effects of L-NMMA (a NO synthase inhibitor) on Glu concentration and amplitude of field excitatory postsynaptic potential (fEPSP) were measured in the DG region during the Morris water maze (MWM) test in freely-moving rats. During the MWM test, compared with the sham group, the escape latency was increased in the place navigation trial, and the percentage of time spent in target quadrant and the number of platform crossings were decreased in the spatial probe trial, in addition, the increase of fEPSP amplitude in the DG was significantly attenuated in AD group rats. L-NMMA significantly attenuated the spatial learning and memory impairment in AD rats, and reversed the inhibitory effect of AD on increase of fEPSP amplitude in the DG during the MWM test. In sham group rats, the Glu level in the DG increased significantly during the MWM test, and this response was markedly enhanced in AD rats. Furthermore, the response of Glu in the DG during spatial learning was recovered by microinjection of L-NMMA into the DG. Our results suggest that NO in the DG impairs spatial learning and memory and related synaptic plasticity in AD rats, by disturbing the Glu response during spatial learning.
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http://dx.doi.org/10.1016/j.bbr.2022.113750 | DOI Listing |
Metab Brain Dis
September 2025
Department of Neuroscience, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran.
Brain ischemia is a major global cause of disability, frequently leading to psychoneurological issues. This study investigates the effects of 4-aminopyridine (4-AP) on anxiety, cognitive impairment, and potential underlying mechanisms in a mouse model of medial prefrontal cortex (mPFC) ischemia. Mice with mPFC ischemia were treated with normal saline (NS) or different doses of 4-AP (250, 500, and 1000 µg/kg) for 14 consecutive days.
View Article and Find Full Text PDFRadiol Adv
September 2024
Department of Radiology, Northwestern University and Northwestern Medicine, Chicago, IL, 60611, United States.
Background: In clinical practice, digital subtraction angiography (DSA) often suffers from misregistration artifact resulting from voluntary, respiratory, and cardiac motion during acquisition. Most prior efforts to register the background DSA mask to subsequent postcontrast images rely on key point registration using iterative optimization, which has limited real-time application.
Purpose: Leveraging state-of-the-art, unsupervised deep learning, we aim to develop a fast, deformable registration model to substantially reduce DSA misregistration in craniocervical angiography without compromising spatial resolution or introducing new artifacts.
Front Artif Intell
August 2025
School of Computation and Communication Science and Engineering, The Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania.
Computer vision has been identified as one of the solutions to bridge communication barriers between speech-impaired populations and those without impairment as most people are unaware of the sign language used by speech-impaired individuals. Numerous studies have been conducted to address this challenge. However, recognizing word signs, which are usually dynamic and involve more than one frame per sign, remains a challenge.
View Article and Find Full Text PDFBeilstein J Nanotechnol
August 2025
School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, United Kingdom.
Atomic resolution scanning probe microscopy, and in particular scanning tunnelling microscopy (STM) allows for high-spatial-resolution imaging and also spectroscopic analysis of small organic molecules. However, preparation and characterisation of the probe apex in situ by a human operator is one of the major barriers to high-throughput experimentation and to reproducibility between experiments. Characterisation of the probe apex is usually accomplished via assessment of the imaging quality on the target molecule and also the characteristics of the scanning tunnelling spectra (STS) on clean metal surfaces.
View Article and Find Full Text PDFAlpha Psychiatry
August 2025
State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, 100875 Beijing, China.
Background: Autism spectrum disorder (ASD) is a multifaceted neurodevelopmental disorder marked by impaired interactions and restricted interests, the pathophysiology of which is not fully understood. The current study explored the potential therapeutic effects of transcranial direct current stimulation (tDCS) on the neurophysiological aspects of ASD, specifically focusing on the brain's excitatory/inhibitory (E/I) balance and behavioral outcomes, providing scientific guidance for ASD intervention.
Methods: Forty-two children with ASD were randomly divided into either an active tDCS or sham tDCS group.