Auditory pathway of the epileptic waltzing mouse. I. A comparison of the acoustic pathways of the normal mouse with those of the totally deaf epileptic waltzer

Waltzing and epilepsy are hereditary traits which appear independently or together in various stocks of mice of the genus Peromyscus. They are inherited in general as Mendelian recessives (Dice, '35; Watson, '39 j. Young members of the particular stock of Peromyscus rnnniculatus artemisiae to be described in this study exhibit both waltzing and epilepsy when stimulated by sounds of various kinds. At the sound of jingling keys, or of certain pure tones, the young epileptic waltzer whirls in circles and then dashes wildly about the enclosure. After a few seconds, he falls upon his side in an epileptic seizure. His body becomes rigid, his forelegs are flexed and his hind legs are extended. The animal resumes his circus movements after recovering from the seizure but whirls in a graceful manner, not wildly as before. As the mouse grows older, it is more and more difficult to induce the waltzing and epileptic attack. Finally, the animal appears to become deaf, for he gives no visible sign that he hears the sound stimulus. His ears do not twitch and he shows no uneasiness. This study represents an attempt to assess possible nervous system changes related to the loss of hearing exhibited by these mice. In Part I of this report, the central relations of the auditory systems in older, deaf epileptic waltzers will be compared with those in normal controls of the genus Peromyscus. The auditory centers of young, partially deaf, epileptic waltzing mice will be considered separately in Part 11. The author is deeply indebted to Dr. Elizabeth C . Crosby €or her helpful criticisms of this paper, and to Dr. Edward Lauer for his suggestions and his assistance in matters of technique. She is also grateful to Dr. Lee R. Dice and the Laboratory of Vertebrate Biology for making the mice and the testing equipment available to her for this study, and to Dr. Elizabeth Barto, who tested the mice for range of hearing. Assistance was obtained from a grant from the Alfonso Morton Clover Scholarship and Research Fund to the Laboratory of Comparative Neurology for the preparation of the material for microscopic examination. Aid in testing the responses of the experimental animals used in this study was supplied through a grant (MH 375 j to Dr. Lee R. Dice from the National Institute of Mental Health, of the National Institutes of Health, Public Health Service.