Phase-locked responses are vital for auditory perception and they may vary with participants' arousal state and age. Two phase-locked neural responses that reflect fine-grained acoustic properties of speech were examined in the current study: the frequency-following response (FFR) to the speech fundamental frequency (F), which originates primarily from the auditory brainstem, and the theta-band phase-locked response (θ-PLV) to the speech envelope that originates from the auditory cortices. The ways these responses were affected by arousal in adults across a wide age-range (19-75 years) were examined. Extracts from electroencephalographic (EEG) responses to repeated syllables were classified into either high or low arousal state based on the occurrence of sleep spindles. The magnitudes of both FFRs and θ-PLVs were statistically greater in the high, than in the low, arousal state. The difference in θ-PLV between the two arousal states was significantly associated with sleep spindle density in the young, but not the older, adults. The results show that (1) arousal affects phase-locked processing of speech at cortical/sub-cortical sensory levels; and that (2) there is an interplay between aging and arousal state which indicates that sleep spindles have an age-dependent neuro-regulatory role on cortical processes. The results lay the grounds for studying how cognitive states affect early-stage neural activity in the auditory system across the lifespan.
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http://dx.doi.org/10.1016/j.neuroimage.2019.01.049 | DOI Listing |
Adv Healthc Mater
January 2025
State Key Laboratory of Natural Medicines, Department of Pharmaceutics, School of Pharmacy, China Pharmaceutical University, No. 639 Longmian Avenue, Nanjing, 211198, P. R. China.
Violet phosphorus (VP) is a phosphorus allotrope first discovered by Hittorf in 1865, which has aroused more attention in the biomedical field in recent years attributed to its gradually discovered unique properties. VP can be further categorized into bulk VP, VP nanosheets (VPNs), and VP quantum dots (VPQDs), and chemical vapor transport (CVT), liquid-phase/mechanical/laser exfoliation, and solvothermal synthesis are the common preparation approaches of bulk VP, VPNs, and VPQDs, respectively. Compared with another phosphorus allotrope (black phosphorus, BP) that is once highly regarded in biomedical applications, VP nanomaterial (namely VPNs and VPQDs) not only exhibits tunable bandgap, moderate on/off current ratio, and good biodegradability, but shows enhanced stability and biosafety as well, allowing it to be a promising candidate for a variety of biomedical applications like antibacterial therapy, anticancer therapy, and biosensing and disease diagnosis.
View Article and Find Full Text PDFPharmacol Res
January 2025
Department of Anesthesiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China; Institute of Anesthesia and Critical Care Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China; Key Laboratory of Anesthesiology and Resuscitation (Huazhong University of Science and Technology), Ministry of Education, Wuhan, China. Electronic address:
General anesthesia is administered to millions of individuals each year, however, the precise mechanism by which it induces unconsciousness remains unclear. While some theories suggest that anesthesia shares similarities with natural sleep, targeting sleep-promoting areas and inhibiting arousal nuclei, recent research indicates a more complex process. Emerging evidence highlights the critical role of corticothalamocortical circuits, which are involved in higher cognitive functions, in controlling arousal states and modulating transitions between different conscious states during anesthesia.
View Article and Find Full Text PDFSleep
December 2024
Midwest Cardiovascular Institute, Naperville, Illinois, USA.
Central sleep apnea (CSA), a rare polysomnographic finding in the general population, is prevalent in certain cardiovascular conditions including systolic and diastolic left ventricular dysfunction, atrial fibrillation, coronary artery disease, carotid artery stenosis, stroke and use of certain cardiac-related medications. Polysomnographic findings of CSA with adverse cardiovascular impacts include nocturnal hypoxemia and arousals, which can lead to increased sympathetic activity both at night and in the daytime. Among cardiovascular diseases, CSA is most prevalent in patients with left ventricular systolic dysfunction; a large study of more than 900 treated patients has shown a dose dependent relationship between nocturnal desaturation and mortality.
View Article and Find Full Text PDFElife
January 2025
Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Harvard Medical School, Massachusetts General Hospital, Charlestown, United States.
High-resolution awake mouse functional magnetic resonance imaging (fMRI) remains challenging despite extensive efforts to address motion-induced artifacts and stress. This study introduces an implantable radio frequency (RF) surface coil design that minimizes image distortion caused by the air/tissue interface of mouse brains while simultaneously serving as a headpost for fixation during scanning. Furthermore, this study provides a thorough acclimation method used to accustom animals to the MRI environment minimizing motion-induced artifacts.
View Article and Find Full Text PDFBackground: The amplitude of resting-state electroencephalographic (rsEEG) rhythms is a promising neurophysiological biomarker to investigate the abnormalities of oscillatory neurophysiological thalamocortical mechanisms related to the general cortical arousal and vigilance in wakefulness in patients with dementia due to neurodegenerative diseases as Alzheimer's disease (ADD), Parkinson's disease (PDD) and Lewy Body disease (DLB). Here, we tested the hypothesis that the reactivity of posterior rsEEG alpha (about 8-12 Hz) rhythms during the transition from eyes-closed to -open condition may be lower in PDD patients than in DLB patients.
Methods: A Eurasian database provided clinical-demographic-rsEEG datasets in 35 ADD patients, 65 PDD patients, 30 DLB patients, and 25 matched cognitively unimpaired (Healthy) persons.
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