Neural Noise

Ultrasound system for precise neuromodulation of human deep brain circuits

2 min read

  • A non-invasive ultrasound system enables precise neuromodulation of deep human brain circuits.1
  • The approach expands alternatives to tDCS/tACS and invasive DBS.1
  • Nature peer-reviewed; human data supports near-term translation.1 1

Weekly enrichment (2026-07-20)

  • The primary source is a Nature Communications 2025 study (University of Michigan; article s41467-025-66832-3) using transcranial low-intensity focused ultrasound (LIFU/tFUS) to modulate deep thalamic circuits non-invasively in humans.23
  • Sixty healthy volunteers (age 25.9 ± 6.3; 38 female, 22 male) were randomized to two duty-cycle groups; six were excluded, leaving 54 (27 per group) for analysis.23
  • LIFU was steered to four subregions of the left thalamus — ventroanterior (VA), ventroposterior (VP), dorsoanterior (DA) and dorsoposterior (DP) — while participants performed a near-threshold visual object-recognition and categorization task analyzed with Signal Detection Theory.2
  • Two conditions contrasted a 70% duty cycle (excitatory) against a 5% duty cycle (inhibitory) at a matched derated spatial-peak temporal-average intensity Ispta.3 = 0.72 W/cm² and 650 kHz fundamental frequency.23
  • High-duty-cycle (70%) stimulation of the matrix-cell-rich, transmodal-dominant VA thalamus selectively enhanced object-recognition sensitivity (d′), and the enhancement magnitude correlated with the core–matrix cell composition of the stimulated region.23
  • A target-invariant effect was also seen: 70% DC stimulation across all four thalamic targets reduced object-categorization accuracy, suggesting a distinct mechanism from the sensitivity effect.2
  • Sonication parameters: pulse repetition frequency 10 Hz, 100 ms pulses, 30 s ON / 30 s OFF epochs; estimated Mechanical Index of 0.20 (70% DC) and 0.77 (5% DC), below ITRUSST safety recommendations.23
  • Simulations estimated roughly 87% energy loss (mainly skull attenuation), and no persistent effect was observed between the two baseline blocks, indicating transient modulation.2
  • The planned n=30 per group exceeded the mean literature sample size (n=19), and the work demonstrates a non-invasive, spatially precise alternative to deep-brain stimulation for probing and modulating deep human brain circuits.24

Footnotes

  1. https://news.google.com/rss/articles/CBMiX0FVX3lxTE1uZUMwMU5IUi1rMnNEaEhSMUFGYjgzWDdsTmVGREN2Z0JrN1ZPVV9uVW9BMlpvdG9SYzU5cFFTN2FrYTFleTNnNHFPOS1YV2pWYkJ4eDRSSndwOVR0S3JV?oc=5 ↩ ↩2 ↩3 ↩4

  2. https://www.nature.com/articles/s41467-025-66832-3 ↩ ↩2 ↩3 ↩4 ↩5 ↩6 ↩7 ↩8 ↩9

  3. https://doi.org/10.1038/s41467-025-66832-3 ↩ ↩2 ↩3 ↩4 ↩5

  4. https://doi.org/10.1101/2024.10.07.617034 ↩

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