Contrary to its well-established role in declarative learning, the impact of sleep on motor memory consolidation remains a subject of debate. Current literature suggests that while motor skill learning benefits from sleep, consolidation of sensorimotor adaptation (SMA) depends solely on the passage of time. This has led to the proposal that SMA may be an exception to other types of memories.
View Article and Find Full Text PDFSleep spindles are thought to promote memory consolidation. Recently, we have shown that visuomotor adaptation (VMA) learning increases the density of spindles and promotes the coupling between spindles and slow oscillations, locally, with the level of spindle-SO synchrony predicting overnight memory retention. Yet, growing evidence suggests that the rhythmicity in spindle occurrence may also influence the stabilization of declarative and procedural memories.
View Article and Find Full Text PDFRecent studies from us and others suggest that traditionally declarative structures mediate some aspects of the encoding and consolidation of procedural memories. This evidence points to the existence of converging physiological pathways across memory systems. Here, we examined whether the coupling between slow oscillations (SO) and spindles, a mechanism well established in the consolidation of declarative memories, is relevant for the stabilization of human motor memories.
View Article and Find Full Text PDFDysphagia is commonly diagnosed in patients living with dementia, but we lack understanding of changes in swallowing physiology and the resulting relationship to impairments of safety and efficiency. The purpose of this study was to describe the pathophysiology of dysphagia in a retrospective sample of patients living with dementia. Videofluoroscopy data from 106 adults (mean age: 84) diagnosed with dementia were scored by blinded raters.
View Article and Find Full Text PDFThe Cobb angle is traditionally used for quantifying the degree of spinal curvature through evaluation of the full spinal cord. When conducting measurements on videofluoroscopy swallowing studies (VFSS), the Cobb angle can measure degree of cervical vertebrae curvature, which may have implications for swallowing. Given that this measure may have utility in dysphagia research, the reliability of this measure taken from C2-C4 and establishing the presence of changes with age were the focus of the current, proof-of-principle study.
View Article and Find Full Text PDFPurpose This document outlines initial recommendations for speech-language pathology management of adult patients with COVID-19 in the acute hospital setting. Method The authors initially developed these recommendations by adapting those developed for physical therapists working with patients with COVID-19 by Thomas et al. (2020).
View Article and Find Full Text PDFAt the time of writing this paper, there are over 11 million reported cases of COVID-19 worldwide. Health professionals involved in dysphagia care are impacted by the COVID-19 pandemic in their day-to-day practices. Otolaryngologists, gastroenterologists, rehabilitation specialists, and speech-language pathologists are subject to virus exposure due to their proximity to the aerodigestive tract and reliance on aerosol-generating procedures in swallow assessments and interventions.
View Article and Find Full Text PDFThe aging population is rapidly growing, requiring speech-language pathologists to better manage a caseload that includes older adults who have a variety of needs. The purpose of this review is to summarize and discuss the current available evidence that will allow speech-language pathologists to make informed clinical decisions when working with older adults. To facilitate this, this article first establishes an understanding of both normal and disordered swallowing physiology in older adults, including how to differentiate between functional changes to swallowing (presbyphagia) and dysphagia.
View Article and Find Full Text PDFGeriatrics (Basel)
January 2019
Oropharyngeal dysphagia is prevalent in several at-risk populations, including post-stroke patients, patients in intensive care and the elderly. Dysphagia contributes to longer hospital stays and poor outcomes, including pneumonia. Early identification of dysphagia is recommended as part of the evaluation of at-risk patients, but available bedside screening tools perform inconsistently.
View Article and Find Full Text PDFDysphagia is estimated to affect ~8% of the world's population (~590 million people). Texture-modified foods and thickened drinks are commonly used to reduce the risks of choking and aspiration. The International Dysphagia Diet Standardisation Initiative (IDDSI) was founded with the goal of developing globally standardized terminology and definitions for texture-modified foods and liquids applicable to individuals with dysphagia of all ages, in all care settings, and all cultures.
View Article and Find Full Text PDFObjective: Evidence is lacking on the preventive effect of oral care on healthcare-associated pneumonia in hospitalized patients and nursing home residents who are not mechanically ventilated. The primary aim of this review was to assess the effectiveness of oral care on the incidence of pneumonia in nonventilated patients.
Methods: We searched 8 databases (MEDLINE, Embase, CENTRAL, CINAHL, Web of Science, LILACS, ICHUSHI, and CiNii), in addition to trial registries and a manual search.
Anomalous patterns of synchronization between basal ganglia and cortex underlie the symptoms of Parkinson's disease. Computational modeling studies suggest that changes in cortical feedback loops involving trans-striatal and trans-subthalamic circuits bring up this anomalous synchronization. We asked whether striatal outflow synchronizes globus pallidus neurons with cortical activity in a rat model of Parkinson's disease.
View Article and Find Full Text PDFUp states are a hallmark of striatal physiology. Spontaneous activity in the thalamo-cortical network drives robust plateau depolarizations in the medium spiny projection neurons of the striatum. Medium spiny neuron firing is only possible during up states and is very tightly regulated by dopamine and NMDA receptors.
View Article and Find Full Text PDFA role of NMDA receptors in corticostriatal synaptic plasticity is widely acknowledged. However, the conditions that allow NMDA receptor activation in the striatum in vivo remain obscure. Here we show that NMDA receptors contribute to sustain the membrane potential of striatal medium spiny projection neurons close to threshold during spontaneous UP states in vivo.
View Article and Find Full Text PDFCoordinated near-threshold depolarized states in cortical and striatal neurons may contribute to form functionally segregated channels of information processing. Recent anatomical studies have identified pathways that could support spiraling interactions across corticostriatal channels, but a functional outcome of such spiraling remains to be identified. Here, we examined whether plateau depolarizations (UP states) in striatal neurons relate better to active epochs in local field potentials recorded from closely related cortical areas than to those recorded in less-related cortical areas.
View Article and Find Full Text PDFThe main clinical manifestations of Parkinson's disease are caused by alterations of basal ganglia activity that are tied in with the progressive loss of mesencephalic dopaminergic neurons. Recent theoretical and modeling studies have suggested that changes in resting neuronal activity occurred later in the course of the disease than those evoked by phasic cortical input. However, there is no empirical support for this proposal.
View Article and Find Full Text PDFDuring movement, inhibitory neurons in the basal ganglia output nuclei show complex modulations of firing, which are presumptively driven by corticostriatal and corticosubthalamic input. Reductions in discharge should facilitate movement by disinhibiting thalamic and brain stem nuclei while increases would do the opposite. A proposal that nigrostriatal dopamine pathway degeneration disrupts trans-striatal pathways' balance resulting in sustained overactivity of basal ganglia output nuclei neurons and Parkinson's disease clinical signs is not fully supported by experimental evidence, which instead shows abnormal synchronous oscillatory activity in animal models and patients.
View Article and Find Full Text PDFThere is a debate as to what modifications of neuronal activity underlie the clinical manifestations of Parkinson's disease and the efficacy of antiparkinsonian pharmacotherapy. Previous studies suggest that release of GABAergic striatopallidal neurons from D2 receptor-mediated inhibition allows spreading of cortical rhythms to the globus pallidus (GP) in rats with 6-hydroxydopamine-induced nigrostriatal lesions. Here this abnormal spreading was thoroughly investigated.
View Article and Find Full Text PDFTo address disparities in access to health care information, we developed a model program of community-based, health education workshops to be delivered in English and Spanish to older urban adults from diverse ethnic, cultural, and language backgrounds. The workshops were created through an interdisciplinary collaboration among faculty from seven health care professions and focused on three healthcare topics identified in Healthy People 2010: dementia and depression, stress reduction, and physical activity. The development of workshop content and structure, including didactic and interactive components, an approach to interdisciplinary student involvement, and program evaluation by clients and community center staff, are presented as a model for other educators.
View Article and Find Full Text PDFIn vivo, cortical neurons and striatal medium spiny neurons (MSN) display robust subthreshold depolarizations (Up states) during which they are enabled to fire action potentials. In the cortex, Up states are believed to occur simultaneously in a neuronal ensemble and to be sustained by local network interactions. It is known that MSN are impelled into the Up state by extra-striatal (primarily cortical) inputs, but the mechanisms that sustain and determine the end of striatal Up states are still debated.
View Article and Find Full Text PDFSevere chronic dopamine (DA) depletion increases the proportion of neurons in the basal ganglia that fire rhythmic bursts of action potential (LFO units) synchronously with the cortical oscillations. Here we report on how different levels of mesencephalic DA denervation affect substantia nigra pars reticulata (SNpr) neuronal activity in the rat and its relationship to akinesia (stepping test). Chronic nigrostriatal lesion induced with 0 (control group), 4, 6 or 8 microg of 6-hydroxydopamine (6-OHDA) into the medial forebrain bundle resulted in a dose-dependent decrease of tyrosine hydroxylase positive (TH+) neurons in the SN and ventral tegmental area (VTA).
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