Ultrasonic Irradiation of the Central Nervous System at High Sound Levels

Abstract

High level ultrasound produces, under properly controlled dosage conditions, selective changes in the central nervous system. A suitable test organism for studying the physical mechanisms involved is the mouse (Strain La F 1) 24 hours after birth. The criterion of nervous damage is paralysis of the hind legs after a single irradiation of the lumbar enlargement of the spinal cord. Damage thresholds, times and intensities, are presented for 982 kc at 10[degree] and 20[degree] C. Hyperthermia of the irradiated cord is probably not a factor in the damage under the test conditions.