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Biomedical subjects

J Schmidt

Publications and source records attributed to J Schmidt.

At least 883 records · Page 49Linked to original sources
PubMed1975

[Long-lasting changes of irritability in the somatosensory cortex of rabbits following tetanic stimulation of the tooth pulp].

Tetanic stimulation of the tooth pulp produced long lasting increases in potentials released by stimulation of the tooth pulp with single stimuli in the sensomotor cortex of rabbits. Stimulation with 200 impulses/sec for 5 sec produced changes of irritability that are demonstrable for 10-50 min depending on the intensity of stimulation. The lower rate limit for producing such changes is 25 impulses/sec. At a rate of 200 impulses/sec, a stimulation time of 25 msec was necessary to produce these changes. The postexcitatory depression occuring after single stimuli within 10-40 msec was increased by tetanic stimulation, whereas facilitation observed 5 msec after single stimuli was unaffected.

Action Potentials↗
PubMed1975

[A statistical study of the interspike-interval distribution of cortical neurons].

Spontaneous activity was recorded extracellularly by glass microelectrodes from 54 neurons of the Gyrus sigmoideus posterior of unnarcotized and gallamine-immobilazed cats, and the sequential and nonsequential interspike-interval histograms were determined using the multi-channel analyzer CAT 400 C. The interval distributions were characterized by graphic criteria, and it was attempted to describe these distributions mathematically by four biparametric distributions, the Weibull, lognormal, gamma and normal distributions. 80% of the frequency distributions of type I (exponential), II (left skew, gamma-similar) and IV (almost symmetrical) could be assigned to these distributions, namely 43% of the lognormal distribution, 32% of the Weibull distribution, and 5% of the gamma distribution. The interval histograms of the type III (left skew, steep) and V (bimodal) could not be described by any of the distributions selected.

Animals↗
PubMed1975

[Influence of orotic acid upon post-excitatory facilitation released by stimulation of the tooth pulp].

The influence of orotic acid on post-excitatory facilitation of evoked potentials released by electric stimulation of the tooth pulp in the sensomotor cortex was studied. 15-360 min following application of 100 mg/kg orotic acid, increase in amplitude of potentials released by stimulation of the tooth pulp, reinforcement of the post-excitatory facilitation observable 5 msec after stimulation occurred.

Animals↗