Journal of Applied Physiology, Vol 43, Issue 2 173-182, Copyright © 1977 by American Physiological Society
Time, rate, and temperature factors in the onset of high-pressure convulsions
R. W. Brauer, R. W. Beaver, S. Lahser, W. M. Mansfield and M. E. Sheehan
An interrupted compression profile technique was used to develop data to
separate the effects of time and pressure factors governing increase of
high-pressure neurological syndrome (HPNS) convulsion threshold pressures
(the compression rate effect) during different compression profiles. A
single differential equation fits all data available to date for
compression rate effect on convulsion thresholds of CD-1 mice (three
distinct types of compression profile; mean compression rates 12-1,000
atm/h). The process leading to increase in HPNS convulsion pressure is
initiated at the very beginning of compression, proceeds at increasingly
rapid rates as higher pressures are attained, and approaches a limiting
upper convulsion pressure. The convulsion threshold pressure in any given
experiment is independent of the compression rate prevailing during the
time immediately preceding onset of the seizure. The magnitude of the
compression rate effect in the CD-1 mouse is independent of chamber
temperature over a range of 27-36 degrees C, and rectal temperatures of
29.2-37.5 degrees C. The bearing of these results on the design of optimal
compression schedules and on the analysis of the neurological mechanisms
underlying the HPNS is discussed.
