Abstract
AbstractLow-intensity transcranial ultrasound stimulation (TUS) is an emerging non-invasive technique for focally modulating human brain function. The mechanisms and neurochemical substrates underlying TUS neuromodulation in humans and how these relate to excitation and inhibition are still poorly understood. In 24 healthy controls, we separately stimulated two deep cortical regions and investigated the effects of theta-burst TUS, a protocol shown to increase corticospinal excitability, on the inhibitory neurotransmitter gamma-aminobutyric acid (GABA) and functional connectivity. We show that theta-burst TUS in humans selectively reduces GABA levels in the posterior cingulate, but not the dorsal anterior cingulate cortex. Functional connectivity increased following TUS in both regions. Our findings suggest that TUS changes overall excitability by reducing GABAergic inhibition and that changes in TUS-mediated neuroplasticity last at least 50 mins after stimulation. The difference in TUS effects on the posterior and anterior cingulate could suggest state- or location-dependency of the TUS effect—both mechanisms increasingly recognized to influence the brain’s response to neuromodulation.
Funder
RCUK | Medical Research Council
Publisher
Springer Science and Business Media LLC
Subject
General Physics and Astronomy,General Biochemistry, Genetics and Molecular Biology,General Chemistry,Multidisciplinary
Reference47 articles.
1. Darmani, G. et al. Non-invasive transcranial ultrasound stimulation for neuromodulation. Clin. Neurophysiol. 135, 51–73 (2022).
2. Yoo, S.-S. et al. Focused ultrasound brain stimulation to anesthetized rats induces long-term changes in somatosensory evoked potentials. Int. J. Imaging Syst. Technol. 28, 106–112 (2018).
3. Yoo, S., Mittelstein, D. R., Hurt, R. C., Lacroix, J. & Shapiro, M. G. Focused ultrasound excites cortical neurons via mechanosensitive calcium accumulation and ion channel amplification. Nat. Commun. 13, 493 (2022).
4. Chu, Y.-C., Lim, J., Chien, A., Chen, C.-C. & Wang, J.-L. Activation of mechanosensitive ion channels by ultrasound. Ultrasound Med. Biol. 48, 1981–1994 (2022).
5. Folloni, D. et al. Ultrasound modulation of macaque prefrontal cortex selectively alters credit assignment–related activity and behavior. Sci. Adv. 7, 6–10 (2021).