D A Poulos

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The efferent projections from nucleus caudalis of the spinal trigeminal complex in cats were studied with retrograde and anterograde axonal transport techniques combined with localization of recording sites in the thalamus and marginal zone of nucleus caudalis to innocuous skin cooling. Results showed brainstem projections from nucleus caudalis to rostral(More)
Psychophysical tests on human subjects showed that judgments of skin indentation depth made when the fingertip was indented at rates from 0.2 to 16 mm/sec were quite insensitive to changes in indentation velocity. Similar results were obtained on the forearm at indentation velocities of 0.4 to 16 mm/sec. Recordings were made from mechanoreceptors in the(More)
The effect of indenting the skin at different rates on the perceived intensity of the stimulus was studied by indenting the skin of the fingertip with two triangular waveforms, given as a pair. The subjects were asked to judge which member of the pair was more intense. Perceived intensity was found to increase both with the depth and the speed of the(More)
The glabrous skin of the monkey's hand was stimulated with a waveform that indented the skin at a rate of 0.4 mm/sec, held the skin steadily or nearly steadily indented for 12 sec or longer, and then retracted back to the starting position. Recordings were made of activity in single afferent fibers in response to these stimuli. The average discharge(More)
Cutaneous thermoreceptors recorded from the trigeminal ganglion of cats anesthetized with urethane showed a significant reduction in thermal sensitivity when compared with neuronal responses obtained from sodium pentobarbital-anesthetized cats. The results of this study indicate that a detailed analysis of primary afferent thermoreceptor response(More)
Experiments were performed on anesthetized cats to determine whether the variability that is common in experimental spinal cord injuries produced by the weight-drop technique can be reduced if a more accurate determination of the actual intensity of the insult to the cord is measured. In addition, determinations of the contribution of such variables as mass(More)
The relationship between the spontaneous spinal electrogram and the degree of spinal cord injury was studied in anesthetic-free, surgically decerebrate cats that received experimental blunt trauma by the graded weight-drop method. It was found that the characteristic spontaneous slow negative potential of the spinal electrogram showed a frequency dependency(More)
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