We investigated whether juvenile rats do not express renewal following extinction of conditioned fear due to their inability to form a long-term contextual fear memory. In experiment 1, postnatal day (P) 18 and 25 rats received 3 white-noise and footshock pairings, followed by 60 white-noise alone presentations the next day. When tested in a different context to extinction, P25 rats displayed renewal whereas P18 rats did not. Experiments 2A and 2B surprisingly showed that P18 and P25 rats do not show differences in contextual and cued fear, regardless of the conditioning-test intervals and the number of white-noise-footshock pairings received. Finally, we observed age differences in contextual fear when P25 rats were weaned at P21 in experiment 3. These results indicate that the developmental dissociation observed in renewal of extinguished fear is not related to the widely believed late emergence of contextual fear learning.
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http://dx.doi.org/10.1002/dev.21516 | DOI Listing |
Cell Mol Life Sci
January 2025
Shanghai Key Laboratory of Anesthesiology and Brain Functional Modulation, Clinical Research Center for Anesthesiology and Perioperative Medicine, Translational Research Institute of Brain and Brain-Like Intelligence, Department of Anesthesiology and Perioperative MedicineSchool of Medicine, Shanghai Fourth People's Hospital, School of Medicine, Tongji University, 1239 Sanmen Road, Hongkou District, Shanghai, 200434, China.
Background: Perioperative neurocognitive disorder (PND) is a prevalent form of cognitive impairment in elderly patients following anesthesia and surgery. The underlying mechanisms of PND are closely related to perineuronal nets (PNNs). PNNs, which are complexes of extracellular matrix primarily surrounding neurons in the hippocampus, play a critical role in neurocognitive function.
View Article and Find Full Text PDFPsychophysiology
January 2025
Binghamton University (SUNY), Binghamton, New York, USA.
Research has shown that exposure to higher rates of neighborhood disadvantage and contextual threat increases risk for the development of psychopathology in youth, with some evidence that these effects may differ across racial/ethnic groups. Although studies have shown that direct exposure to stress impacts neural responses to threat-relevant stimuli, less is known about how neighborhood characteristics more generally (e.g.
View Article and Find Full Text PDFSci Rep
January 2025
Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, 04510, Mexico City, Mexico.
Autism spectrum disorder (ASD) comprises alterations in brain anatomy and physiology that ultimately affect information processing and behavior. In most cases, autism is considered idiopathic, involving alterations in numerous genes whose functions are not extensively documented. We evaluated the C58/J mouse strain as an idiopathic model of ASD, emphasizing synaptic transmission as the basis of information processing.
View Article and Find Full Text PDFJ Neurosci
December 2024
Neurobiology Laboratory, National Institute of Environmental Health Sciences, Division of Intramural Research, National Institute of Health, Research Triangle Park, North Carolina 27713, USA
Perineuronal nets (PNNs) are a specialized extracellular matrix that surround certain populations of neurons, including (inhibitory) parvalbumin (PV) expressing-interneurons throughout the brain and (excitatory) CA2 pyramidal neurons in hippocampus. PNNs are thought to regulate synaptic plasticity by stabilizing synapses and as such, could regulate learning and memory. Most often, PNN functions are queried using enzymatic degradation with chondroitinase, but that approach does not differentiate PNNs on CA2 neurons from those on adjacent PV cells.
View Article and Find Full Text PDFFront Glob Womens Health
December 2024
Optentia Research Unit, North-West University, Vanderbijlpark, South Africa.
Objective: This article aims to examine the influence of individual and community-contextual factors on the well-being of older women in Zambia during the COVID-19 pandemic, drawing on Bronfenbrenner's process-person-context-time model.
Methods: Secondary data from the nationally representative 2021 SEIA were used, and bivariate and logistic regression analyses were performed to determine factors associated with the well-being of older women during the COVID-19 pandemic.
Results: Overall, 29% (613) of older women reported a decline in their well-being due to COVID-19.
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