Preyer's Reflex Research Articles

AN EXPERIMENTAL STUDY OF THE INFLUENCE OF STREPTOMYCIN ADMINISTERED TO MOTHER OF FETAL AUDITORY ORGANS

Dihydrostreptomycin was administered daily intraperitoneally to pregnant adult female mice in various doses from the first day of pregnancy to partison.As the dose was increased, tendencies of shortening of pregnancy duration and decrease in fetal body weight at partition were observed.The examination of the fetal audition by Preyer's Reflex revealed no difference between the control group and the group to which dihydrostreptomysin was administered in large doses.

A STUDY ON EXPERIMENTAL ACOUSTIC TRAUMA IN ANIMALSWITH THE INJURY OF KIDNEYS OR LIVER

Guinea pigs were treated with HgCI2 or Cantharidin for the kidneys and CCI4 or dl-Ethionine for the liver, so that no histopathological changes of the auditary organ developed, and the acoustic stimuli were given.The treated animals were asumed to have developed unhealthy intrinsic factors, the ear being Locus minoris resistantae to the acoustic trauma. The acoustic stimuli loaded were 120 Phon at 2000 cps repeated for 10 day(for 2 hours every other day)or 110 Phon repeated for 10 days(for 2 hours daily).It was confirmed that the acoustic stimuli caused no pathological changes of the auditoryor- gan. The results, obtained were as follows: 1)When the animals with the injury of kidneys were exposed to the acoustic sti- muli, degeneration of cells were observed at the 2 nd turn of Corti's organ. 2)When the animals with the injury of liver were exposed to the acoustic sti- muli, degeneration of cells were observed at the 2nd turn of Corti's organ. 3)Preyer's reflex test showed an obvious impairment in the high tone region. It was concluded that the susceptibility to acoustic trauma was increased in those animals with the injury of kidneys or liver.

A NEW TEST FOR THE DIAGNOSIS OF DISEASE OF THE INNER EAR

That the auricles of both human beings and animals show involuntary movement on acoustic irritation has been established in the otologic literature since the beginning of the last century. Known as Preyer's reflex, since Preyer¹revealed that the striking of tuning forks caused an involuntary jerking reflex of the auricle in new-born guinea-pigs and young rats, this phenomenon has been noted time and again, and is constantly employed in physiologic experimentation on animals as a proof that the animal hears. This reflex movement has also been discerned in man, and is described in the older as well as in the newer handbooks on otology. Lincke²and Politzer³frequently found patients having pathologic conditions in the ear who showed unconscious movements of the auricle either in a single circumscribed sector or in toto. Similar observations were mentioned by Urbantschitsch⁴and Lucae.⁵Schaefer and Giesswein

Demonstration of Preyer's Reflex through bone conduction of sound

Demonstration of Preyer's Reflex through bone conduction of sound