BOLD signal response in primary visual cortex to flickering checkerboard increases with stimulus temporal frequency in older adults

Uchiyama, Yuji; Sakai, Hiroyuki; Ando, Takafumi; Tachibana, Atsumichi; Sadato, Norihiro

doi:10.1371/journal.pone.0259243

Cited by 1 publication

(1 citation statement)

References 48 publications

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“…A black-and-white, radial checkerboard stimulus was presented to the participants to induce activation in the primary visual cortex (V1). The polarity of the checkerboard was reversed at a frequency of 8 Hz (every 125 ms), which has been shown to robustly activate V1 in older adults 58 , and has been used in previous studies investigating neurovascular coupling in V1 59 . The checkerboard stimuli were presented in 6.8 s blocks, with jittered inter-trial intervals (ITIs) between each period of visual stimulation which were optimised using optseq (Version 2.0, Center for Functional Neuroimaging Technologies, Massachusetts General Hospital, Harvard, US).…”

Section: Methodsmentioning

confidence: 99%

Evidence for direct control of neurovascular function by circulating platelets in healthy older adults

Rossetti,

Dunster,

Sohail

et al. 2024

Preprint

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SUMMARYPlatelets play a vital role in preventing haemorrhage through haemostasis, but complications arise when platelets become overly reactive, leading to pathophysiology such as athero-thrombosis1,2. Elevated haemostatic markers are linked to dementia3and predict its onset in long-term studies4. Despite epidemiological evidence, the mechanism linking haemostasis with early brain pathophysiology remains unclear. Here, we aimed to determine whether a mechanistic association exists between platelet function and neurovascular function in 52 healthy mid- to older-age adults. To do this, we combined, for the first time, magnetic resonance imaging (MRI) of neurovascular function, peripheral vascular physiology, and in vitro platelet assaying. We show a direct association between platelet reactivity and neurovascular function that is both independent of vascular reactivity and mechanistically specific: Distinct platelet signalling mechanisms (Adenosine 5’-diphosphate, Collagen-Related Peptide, Thrombin Receptor Activator Peptide 6) were directly associated with different physiological components of the haemodynamic response to neural (visual) stimulation (full-width half-maximum, time to peak, area under the curve), an association that was not mediated by peripheral vascular effects. This finding challenges the previous belief that systemic vascular health determines the vascular component of neurovascular function, highlighting a specific link between circulating platelets and the neurovascular unit. Since altered neurovascular function marks the initial stages of neurodegenerative pathophysiology5, understanding this novel association becomes now imperative, with the potential to lead to a significant advancement in our comprehension of early dementia pathophysiology.

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Section: Methodsmentioning

confidence: 99%