The formation of trace rhythm assimilation (an analog of the conditioned reflex to time) by neurons of the sensorimotor cortex in response to prolonged (10-20 min) electrodermal stimulation of an extremity at a frequency of 0.5-1 or 2 Hz was investigated in awake adult (5-7 months), old (54-65 months), and very old (66-85 months) rabbits. The data of the spectral analysis of the impulse activity of 460 neurons showed aged-related differences in the formation of trace rhythm assimilation by neurons: it takes place after one to two series (1st to 2nd days of the experiment) in young animals; after two to four series of periodic stimulation (2nd to 3rd days of the experiment) in the old animals; in very old animals rhythmic stimulation essentially did not result in rhythm assimilation by cortical neurons. Quantitative and qualitative morphological changes in nerve and glial cells in the sensorimotor cortex of old rabbits as compared with young rabbits were identified. It is hypothesized that deviations in the course of mnestic processes observed in animals during aging may be associated with destructive phenomena in the neocortex during normal aging.
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http://dx.doi.org/10.1007/BF01183002 | DOI Listing |
Alzheimers Res Ther
January 2025
Department of Neurology, University Medical Center Rostock, 18147, Rostock, Germany.
Background: Degeneration of the basal forebrain cholinergic system is a hallmark feature shared by Alzheimer's disease (AD) and Lewy body disease (LBD) whereas hippocampus atrophy is more specifically related to AD. We aimed to investigate the relationship between basal forebrain and hippocampus atrophy, cognitive decline, and neuropathology in a large autopsy sample.
Methods: Data were obtained from the National Alzheimer's Coordinating Center (NACC).
World Neurosurg
January 2025
Department of Neurosurgery, SMS Medical College and Hospital, Jaipur, Rajasthan, India.
Objective: This study evaluates the extent of perfusion abnormalities in pediatric traumatic head injury patients by using computed tomography perfusion (CTP) and compares the efficacy of voxel based and whole brain perfusion data clinically with functional outcome scales GOSE-P and MRS.
Methodology: In this Prospective study 100 eligible patients of age group 0-15 years were enrolled. Subjects were categorized into mild, moderate and severe traumatic brain injury using GCS.
Commun Biol
January 2025
Department of Neurology, Peking University First Hospital, Beijing, People's Republic of China.
Persistent Postural-Perceptual Dizziness (PPPD) is a common cause of chronic vestibular syndrome. Although previous studies have identified central abnormalities in PPPD, the specific neural circuits and the alterations in brain network topological properties, and their association with dizziness and postural instability in PPPD remain unclear. This study includes 30 PPPD patients and 30 healthy controls.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, BC, Canada.
People with amblyopia show deficits in global motion perception, especially at slow speeds. These observers are also known to have unstable fixation when viewing stationary fixation targets, relative to healthy controls. It is possible that poor fixation stability during motion viewing interferes with the fidelity of the input to motion-sensitive neurons in visual cortex.
View Article and Find Full Text PDFJ Prev Alzheimers Dis
February 2025
Department of Psychosomatic Medicine, University Medicine Rostock, Rostock, Germany; Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE), Greifswald, Rostock, Germany.
Background: Imaging studies showed early atrophy of the cholinergic basal forebrain in prodromal sporadic Alzheimer's disease and reduced posterior basal forebrain functional connectivity in amyloid positive individuals with subjective cognitive decline. Similar investigations in familial cases of Alzheimer's disease are still lacking.
Objectives: To test whether presenilin-1 E280A mutation carriers have reduced basal forebrain functional connectivity and whether this is linked to amyloid pathology.
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