Low-Intensity Pulsed Ultrasound Stimulation Induces Coupling Between Ripple Neural Activity and Hemodynamics in the Mouse Visual Cortex

Abstract Several studies have separately investigated neural activities and hemodynamic responses induced by low-intensity pulsed ultrasound stimulation (LIPUS), less is known about their coupling under LIPUS. This study aims to investigate the neurovascular coupling with LIPUS by measuring neural activity and hemodynamics. We found that the relative power and sample entropy of local field potential at the ripple band have a significant correlation to relative cerebral blood flow over time (correlation coefficients: 0.66 ± 0.13 [P < 0.01] and −0.58 ± 0.11 [P < 0.05]). These results demonstrate that LIPUS can induce neurovascular coupling in the mouse visual cortex.

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The effect of low-intensity transcranial ultrasound stimulation on neural oscillation and hemodynamics in the mouse visual cortex depends on anesthesia level and ultrasound intensity

IEEE Transactions on Biomedical Engineering ◽

10.1109/tbme.2021.3050797 ◽

2021 ◽

pp. 1-1

Author(s):

Yi Yuan ◽

Kaiqing Zhang ◽

Yiyao Zhang ◽

Jiaqing Yan ◽

Zhijie Wang ◽

...

Keyword(s):

Visual Cortex ◽

Transcranial Ultrasound ◽

Neural Oscillation ◽

Low Intensity ◽

Ultrasound Stimulation ◽

Ultrasound Intensity ◽

Anesthesia Level ◽

Mouse Visual Cortex

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Osteocytes as main responders to low-intensity pulsed ultrasound treatment during fracture healing

Scientific Reports ◽

10.1038/s41598-021-89672-9 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Tatsuya Shimizu ◽

Naomasa Fujita ◽

Kiyomi Tsuji-Tamura ◽

Yoshimasa Kitagawa ◽

Toshiaki Fujisawa ◽

...

Keyword(s):

Fracture Healing ◽

Transcriptional Control ◽

Target Genes ◽

Pulsed Ultrasound ◽

Activated T Cells ◽

In Vivo Models ◽

Low Intensity Pulsed Ultrasound ◽

Low Intensity ◽

Ultrasound Stimulation

AbstractUltrasound stimulation is a type of mechanical stress, and low-intensity pulsed ultrasound (LIPUS) devices have been used clinically to promote fracture healing. However, it remains unclear which skeletal cells, in particular osteocytes or osteoblasts, primarily respond to LIPUS stimulation and how they contribute to fracture healing. To examine this, we utilized medaka, whose bone lacks osteocytes, and zebrafish, whose bone has osteocytes, as in vivo models. Fracture healing was accelerated by ultrasound stimulation in zebrafish, but not in medaka. To examine the molecular events induced by LIPUS stimulation in osteocytes, we performed RNA sequencing of a murine osteocytic cell line exposed to LIPUS. 179 genes reacted to LIPUS stimulation, and functional cluster analysis identified among them several molecular signatures related to immunity, secretion, and transcription. Notably, most of the isolated transcription-related genes were also modulated by LIPUS in vivo in zebrafish. However, expression levels of early growth response protein 1 and 2 (Egr1, 2), JunB, forkhead box Q1 (FoxQ1), and nuclear factor of activated T cells c1 (NFATc1) were not altered by LIPUS in medaka, suggesting that these genes are key transcriptional regulators of LIPUS-dependent fracture healing via osteocytes. We therefore show that bone-embedded osteocytes are necessary for LIPUS-induced promotion of fracture healing via transcriptional control of target genes, which presumably activates neighboring cells involved in fracture healing processes.

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