A study of reception with the use of focused ultrasound. II. Effects on the animal receptor structures.

Brain Research (Impact Factor: 2.83). 11/1977; 135(2):279-85. DOI: 10.1016/0006-8993(77)91031-9
Source: PubMed

ABSTRACT The possibility of stimulation of receptor structures with focused ultrasound (focused beam of high frequency mechanical waves) was investigated. Stimulation of single Pacinian corpuscle isolated from cat's mesentery resulted in receptor and action potentials. Stimulation of frog's ear labyrinth resulted in evoked potentials recorded from midbrain auditory area, their characteristics being much the same as those for responses to adequate sound stimuli. It is concluded that focused ultrasound is an advantageous agent for stimulation of various mechanoreceptors both isolated and, especially, located deep in the body. Some problems related to sensory specificity are discussed.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Nine traditional Healers, 12 of their Patients, 11 Healer Simulators, and 20 Patient Controls participated in a study to examine a variety of physiological concomitants of the "laying-on of hands." Focused ultrasound was used to obtain participants' tactile-sensitivity thresholds. Tactile thresholds were re-examined: (1) after healing interactions (Healers, Patients), (2) after simulated healing interventions (Healer Simulators), or (3) after rest intervals with no prior healing-related activity (Patient Controls). Presession to postsession changes for the four groups of participants were examined with Repeated Measures Analysis of Covariance (ANCOVA), controlling for age. The ANCOVA found a significant Main Effect of Group (F = 31.20, df = 3,34, p < .0001). Post-hoc Tukey tests determined that changes in Healers' right-hand fingertip thresholds were significantly different from changes in the right-hand fingertip thresholds of Patients, Healer Simulators, and Patient Controls. Patients' right-hand fingertip-threshold change also differed significantly from that of Patient Controls. Repeated Measures ANCOVA performed on Healers' and Patients' right- and left-hand palm sensitivity thresholds showed a significant Main Effect of Time (Before vs. After) (F = 5.78, df = 1,9, p = .04), and a significant Time x Group interaction (F = 7.04, df = 1,9, p = .02). No significant task-dependent changes were found in auditory reaction-time tests conducted with the four groups of participants. Discussion includes pilot data from a variety of supplementary tests.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Potential peripheral sources of deep pain can require invasive evocative tests for their assessment. Here we perform research whose ultimate goal is development of a non-invasive evocative test for deep painful tissue. We used a rat model of inflammation to show that intense focused ultrasound (iFU) differentially stimulates inflamed versus control tissue and can identify allodynia. To do so we applied iFU to inflamed and normal tissue below the skin of rats' hind paws and measured the amount of ultrasound necessary to induce paw withdrawal. iFU of sufficient strength (spatial and temporal average intensities ranged from 100-350 W/cm(2)) caused the rat to withdraw its inflamed paw, while the same iFU applied to the contralateral paw failed to induce withdrawal, with sensitivity and specificity generally greater than 90%. iFU stimulation of normal tissue required twice the amount of ultrasound to generate a withdrawal than did inflamed tissue, thereby assessing allodynia. Finally, we verified in a preliminary way the safety of iFU stimulation with acute histological studies coupled with mathematical simulations. Given that there exist systems to guide iFU deep to the skin, image-guided iFU may one day allow assessment of patient's deep, peripheral pain generators.
    Journal of therapeutic ultrasound. 01/2014; 2:8.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Previous studies have observed that individual pulses of intense focused ultrasound (iFU) applied to inflamed and normal tissue can generate sensations, where inflamed tissue responds at a lower intensity than normal tissue. It was hypothesized that successively applied iFU pulses will generate sensation in inflamed tissue at a lower intensity and dose than application of a single iFU pulse. This hypothesis was tested using an animal model of chronic inflammatory pain, created by injecting an irritant into the rat hind paw. Ultrasound pulses were applied in rapid succession or individually to rats' rear paws beginning at low peak intensities and progressing to higher peak intensities, until the rats withdrew their paws immediately after iFU application. Focused ultrasound protocols consisting of successively and rapidly applied pulses elicited inflamed paw withdrawal at lower intensity and estimated tissue displacement values than single pulse protocols. However, both successively applied pulses and single pulses produced comparable threshold acoustic dose values and estimates of temperature increases. This raises the possibility that temperature increase contributed to paw withdrawal after rapid iFU stimulation. While iFU-induction of temporal summation may also play a role, electrophysiological studies are necessary to tease out these potential contributors to iFU stimulation.
    The Journal of the Acoustical Society of America 08/2013; 134(2):1521-9. · 1.65 Impact Factor


Available from
May 16, 2014