Transcranial focused ultrasound (tFUS) is an emerging method for non-invasive neuromodulation akin to transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS). tFUS offers several advantages over electromagnetic methods including high spatial resolution and the ability to reach deep brain targets. Here we describe two experiments assessing whether tFUS could modulate mood in healthy human volunteers by targeting the right inferior frontal gyrus (rIFG), an area implicated in mood and emotional regulation. In a randomized, placebo-controlled, double-blind study, participants received 30 s of 500 kHz tFUS or a placebo control. Visual Analog Mood Scales (VAMS) assessed mood four times within an hour (baseline and three times after tFUS). Participants who received tFUS reported an overall increase in Global Affect (GA), an aggregate score from the VAMS scale, indicating a positive shift in mood. Experiment 2 examined resting-state functional (FC) connectivity using functional magnetic resonance imaging (fMRI) following 2 min of 500 kHz tFUS at the rIFG. As in Experiment 1, tFUS enhanced self-reported mood states and also decreased FC in resting state networks related to emotion and mood regulation. These results suggest that tFUS can be used to modulate mood and emotional regulation networks in the prefrontal cortex.
Ultrasound consists of megahertz mechanical vibrations, and is widely used for medical imaging. As microtubules have megahertz vibrations, we have been studying ultrasound effects on the brain, delivered non-invasively from the scalp – ‘transcranial ultrasound’ (‘TUS’). We performed the first clinical trial of transcranial ultrasound (TUS) on mental states on human volunteers, finding that 15 seconds of sub-thermal 8 MHz ultrasound applied at the fronto-temporal scalp resulted in 40 minutes of mood improvement compared with placebo.
With the discovery of coherent megahertz vibrations in microtubules (2012, Anirban Bandyopadhyay group in Japan), Hameroff proposed that low intensity, non-invasive megahertz vibrations – ultrasound – to the brain could therapeutically stimulate microtubule resonance and polymerization, and improve mental and cognitive states. He and UA Anesthesiology colleagues performed and published the first clinical trial showing mood enhancement by non-invasive transcranial ultrasound (‘TUS’) in human volunteers in 2013 in Brain Stimulation. Now collaborating with Psychology professor John JB Allen, Jay Sanguinetti, and, in the College of Medicine, Bellal Joseph (Surgery), Rich Amini (Emergency Medicine), and Todd Vanderah (Pharmacology), and with funding from the Penrose Institute, the group is planning TUS clinical studies for Alzheimer’s, depression, traumatic brain injury, addiction/withdrawal, migraine and induced meditative states.
Sanguinetti JL, Hameroff S, Smith EE, Dieckman LW, Sato T, Daft CMW, Tyler WJ, Allen JJB. Transcranial focused ultrasound (tFUS) over the right prefrontal cortex improves mood and alters functional connectivity in humans. (submitted 2019)
Hameroff, Stuart. (with John JB Allen and Jay Sanguinetti. Department of Psychology, University of Arizona) ‘Transcranial ultrasound (‘TUS’) effects on mood and memory in human volunteers’ Presentation, 2nd International Brain Stimulation Conference, Barcelona, Spain, March 5-8, 2017
Hameroff, Stuart. Google Sci-Foo, Invited Speaker, 2016
a) Lightning talk – ‘Good vibrations – Tuning the brain with transcranial ultrasound’ Invited Speaker
b) ‘Quantum physics and consciousness’ (session on the future of physics with Max Tegmark and Nobel laureate Frank Wilczek), Google Campus, Mountain View, California, July 22-24, 2016.
Sanguinetti JL, Smith E, Allen John JB, and Hameroff S. (2014). “Human Brain Stimulation with Transcranial Ultrasound: Potential Applications for Mental Health.” Bio electromagnetic and Subtle Energy Medicine, 2nd edition, CRC Press, pp 355-360, 13-08-2014.
Stuart Hameroff and colleagues performed the first clinical trial of trancranial ultrasound (TUS) on mental states, finding improved mood after 15 seconds of sub-thermal 8 MHz ultrasound compared with placebo applied at the temporal skull. Another project is being planned numerous colleagues including, UA professor of psychology John Allen and postdoc Jay Sanguineti for mood, cognition and psychological and neurological disorders (including post-operative cognitive dysfunction) and others, tba.
Microtubules within brain neurons are thought to resonate at megahertz frequencies, precisely where ultrasound acts. We hope to enhance mood, and treat various neurological disorders by stimulating brain microtubule dynamics through TUS.
Two subsequent TUS studies done in collaboration with UA professor of psychology John Allen and post-doc Jay Sanguinetti have shown similar mood improvement from brief, sub-thermal TUS. These studies are currently being written up for publication.‘
Non-invasive brain stimulation techniques aimed at mental and neurological conditions include transcranial magnetic stimulation (TMS) for depression, and transcranial direct current (electrical) stimulation (tDCS), shown to improve memory. Transcranial ultrasound stimulation (TUS) has also shown promise.
Mood disorders, Alzheimer’s disease, traumatic brain injury (TBI) and post-traumatic stress disorders (PTSD) are enormous problems for those afflicted, their families, caregivers and society in general. Current treatments for these disorders are modestly effective at best, and new, more effective and inexpensive approaches are needed. A major hurdle in treatment is the lack of understanding in mainstream approaches as to how the brain works normally, how mood, cognition, memory and consciousness derive from synaptic computation among neurons. However evidence now suggests mental states may depend, to some extent at least, on vibrations, e.g. sound wave solitons in neuronal membranes, and megahertz (‘MHz’, 106 to 107 Hz) resonances in microtubule networks inside neurons. In TBI and Alzheimer’s disease, microtubules are disrupted and release ‘tau’, a microtubule-associated protein. Under normal circumstances, microtubules are directly responsible for neuronal and synaptic growth, repair and plasticity.
Ultrasound (US) consists of mechanical oscillations, e.g. in MHz. ‘Transcranial ultrasound’ (‘TUS’) passes low intensity, sub-thermal US through the skull into the brain, safely and painlessly. In clinical trials, TUS improves human mood and cognition, and in lab studies megahertz stimulation promotes microtubule assembly. We propose to determine safety and efficacy of inexpensive and potentially portable TUS technology for improving recovery from TBI, Alzheimer’s disease.
Hypothesis or Objective: High intensity US can heat, cavitate and ablate kidney stones, brain tumors and other tissue. Mid-intensity US (‘diathermy’) causes mild heating, useful for musculoskeletal problems. Low intensity, ‘sub-thermal’ US (<720 mW/cm2 by FDA guidelines) excites peripheral neurons,4 and promotes their regeneration after injury. Applied at the scalp, low intensity TUS is FDA-approved for brain imaging, though supplanted by CT, MRI etc. TUS is still used to image brains of newborn babies through boneless fontanelles, and can be focused anywhere in the adult brain. WJ Tyler and others first showed low intensity TUS caused behavioral and electrophysiological changes in animals, and more recently cognitive enhancement in humans.
In the first TUS study on human mental states,11 our group showed that 15 seconds of 8 MHz TUS to fronto-temporal cortex from temporal scalp at 150 mW/cm2 resulted in 40 minutes of improved mood compared to sham exposure. Further studies12 have shown optimal mood improvement with 2 MHz TUS for 30 seconds to right fronto-temporal cortex. In some cases, vertex stimulation (targeting cingulate cortex) resulted in uncontrolled laughter, “out of body” experiences and feelings of being “more in the moment”. High frequency (gamma synchrony) EEG was increased near the TUS stimulation site.
Regarding cellular and molecular level mechanisms, Tyler suggested TUS promotes vibrations in a mechanical continuum of extracellular, intra-membrane and intra-neuronal structures. Among these are microtubules, self-assembling polymers of tubulin, the brain’s most prevalent protein. TUS might act by tuning or enhancing endogenous microtubule megahertz resonances.
Cellular damage in TBI is attributed to biochemical cascades, apoptosis, inflammation, free radicals, glutamate excitotoxicity, blood brain barrier breakdown, axon shearing, and cytoskeletal disruption. Regardless, neuronal recovery and synaptic formation require microtubule-dependent extension of axonal and dendritic ‘neurites’. TUS may stimulate neuronal repair (e.g. for TBI) and memory turnover (PTSD). TUS warrants clinical trials for TBI, Alzheimer’s disease and PTSD.
Our previous TUS studies have used a clinical GE Logiq US imaging device, and the U+ single transducer TUS headset from Thync, Tyler’s company (formerly NeuroTrek). Both devices are limited in range of MHz frequencies for testing. We are collaborating with Sterling Cooley (Berkeley Ultrasound, Berkeley, California) who has developed a TUS device called the NeuroResonator 1 (NR1) which we tested and calibrated in October, 2014. Proposed modifications will upgrade to the battery-powered NeuroResonator 2 (‘NR2’) with multiple US piezo transducer/emitters with various lead placements, each emitter controlled individually, able to be aimed at particular brain areas, driven synchronously, sequentially, in any combination and/or pulse modulated, e.g. by music. The NR2 will be calibrated, tested, and reviewed and approved by our Bioengineering and Institutional Review Board. Stimulation sites will be selected based on injured brain area, right fronto-temporal and other areas. We plan pilot studies commencing early spring 2015 and will search for optimal techniques. With the NR2 fitting in an EEG cap, we will also study TUS effects on simultaneous EEG.
Good vibrations: Mediating mood through brain ultrasound – Researchers have developed a novel technique to affect mood through ultrasound vibrations applied to the brain. Their findings could potentially lead to new treatments for psychological and …full story, Science Daily, July 18, 2013