Effects of underwater sound exposure on neurological function and brain histology.
To evaluate the safety of sonar exposure from a neurological perspective, the vulnerability of the central nervous system to underwater exposure with high-intensity, low-frequency sound (HI-LFS) was experimentally examined. Physiological, behavioral and histological parameters were measured in anesthetized, ventilated rats exposed to brief (5 min), underwater HI-LFS. Exposure to 180 dB sound pressure level (SPL) re 1 microPa at 150 Hz (n = 9) did not alter acute cardiovascular physiology (arterial blood pH, pO(2), pCO(2), heart rate, or mean arterial blood pressure) from that found in controls (n = 11). Rats exposed to either 180 dB SPL re 1 microPa at 150 Hz (n = 12) or 194 dB SPL re 1 microPa at 250 Hz (n = 12) exhibited normal cognitive function at 8 and 9 days after sound exposure. Evaluation of neurological motor function revealed a minor deficit 7 days after 180 dB SPL/150 Hz exposure that resolved by 14 days, and no deficits after 194 dB SPL/250 Hz exposure. No overt histological damage was detected in any group. These data suggest that underwater HI-LFS exposure may cause transient, mild motor dysfunction.
Department of Neurosurgery, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA.
Helmut L
HL
Laurer
Andrew N
AN
Ritting
Andrew B
AB
Russ
Florence M
FM
Bareyre
Ramesh
R
Raghupathi
Kathryn E
KE
Saatman
D000704:Analysis of Variance; D000818:Animals; D002320:Cardiovascular Physiological Phenomena; D002493:Central Nervous System Diseases / Q000209:etiology / Q000473:pathology / Q000503:physiopathology; D004242:Diving; D009622:Noise / Q000009:adverse effects*; D011597:Psychomotor Performance / Q000502:physiology*; D051381:Rats; D015837:Vestibular Diseases / Q000209:etiology* / Q000503:physiopathology*