Transcranial focused ultrasound shows promise to treat forms
Neuromodulation comprises a range of therapeutic approaches to relieving symptoms, such as pain or tremors, or to restore movement or function. Therapeutic stimulation of neurons with electrical energy or chemicals-; and potentially with acoustic waves-; can amplify or dampen neuronal impulses in the brain or body.

Acoustic signals in the form of ultrasound offer a promising class of neuromodulation which would be an especially valuable approach because it is non-invasive-; no surgical procedure to implant electrodes for stimulation is required. Ultrasound offers a temporary modulation that can be tuned for the desired effect. Now researchers have demonstrated that it has the potential to be targeted at neurons with specific functions.

A team has demonstrated the potential of a neuromodulation approach that uses low-intensity ultrasound energy, called transcranial focused ultrasound-; or tFUS. For their studies, the team designed an assembly that included an ultrasound transducer and a device that records data from neuron signals, called a multi-electrode array. During experiments with anesthetized rodents, the researchers penetrated the skull and brain with various brief pulses of acoustic waves, targeting specific neurons in the brain cortex. They simultaneously recorded the change in electrophysiological signals from different neuron types with the multi-electrode array.

When a signal is sent from one neuron to another, whether engaging the senses or controlling movement, the firing of that signal across the synapse, or junction, between neurons is called a spike. Two types of neurons observed by the researchers are excitatory and inhibitory neurons.

When the researchers used tFUS to emit repeated bursts of ultrasound stimulation directly at excitatory neurons, they observed an elevated impulse rate or spike. They observed that inhibitory neurons subjected to the same tFUS energy did not display a significant spike rate disturbance. The study demonstrated that the ultrasound signal can be transmitted through the skull to selectively activate specific neuron sub-populations, in effect targeting neurons with different functions.

The application of this research has broad implications; it's not just limited to one disease. For many people suffering from pain, depression and addiction, He believes non-invasive tFUS neuromodulation could be used to facilitate treatment. "If we can localize and target areas of the brain using acoustic, ultrasound energy, I believe we can potentially treat a myriad of neurological and psychiatric diseases and conditions," He said.