Focused ultrasound modulates region-specific brain activity

Abstract

We demonstrated the in vivo feasibility of using focused ultrasound (FUS) to transiently modulate (through either stimulation or suppression) the function of regional brain tissue in rabbits. FUS was delivered in a train of pulses at low acoustic energy, far below the cavitation threshold, to the animal's somatomotor and visual areas, as guided by anatomical and functional information from magnetic resonance imaging (MRI). The temporary alterations in the brain function affected by the sonication were characterized by both electrophysiological recordings and functional brain mapping achieved through the use of functional MRI (fMRI). The modulatory effects were bimodal, whereby the brain activity could either be stimulated or selectively suppressed. Histological analysis of the excised brain tissue after the sonication demonstrated that the FUS did not elicit any tissue damages. Unlike transcranial magnetic stimulation, FUS can be applied to deep structures in the brain with greater spatial precision. Transient modulation of brain function using image-guided and anatomically-targeted FUS would enable the investigation of functional connectivity between brain regions and will eventually lead to a better understanding of localized brain functions. It is anticipated that the use of this technology will have an impact on brain research and may offer novel therapeutic interventions in various neurological conditions and psychiatric disorders.

Precise Neural Stimulation in the Retina Using Focused Ultrasound

“…Although these studies clearly demonstrate neurostimulation, there was little control over the spatial extent of the stimulation, which was generally quite large (ϳ2 mm lateral). In a similar study using "focused" US that activated rabbit motor cortex measured by fMRI and behavior, the size of the acoustic focus was estimated to be 2.3 mm in diameter and 5.5 mm in length (Yoo et al, 2011). Finally, recent work has shown the feasibility of in vivo retinal stimulation (Naor et al, 2012) .…”

High-intensity focused ultrasound: past, present, and future in neurosurgery

“…15,25,26,70,86 Other studies have demonstrated activation of neural tissue, both peripherally and in the CNS. 32,50,81 These effects have been postulated to occur as a result of mechanical stimuli (reversible) and thermal ablation (potentially irreversible).…”

The use of transcranial focused ultrasound in CNS diseases

“…Как лабора-торные исследования на животных, так и некоторые со-временные доклинические исследования свидетельству-ют о способности ФУЗ вызывать in vivo контролируемые нейромодулирующие -стимулирующие и ингибирую-щие эффекты [66][67][68][69][70][71][72][73][74]. УЗ низкой интенсивности не приводит к изменению температуры в мишени и вокруг нее, а также, по результатам гистологических исследова-ний, не вызывает явных повреждений в тканях.…”