The Post-Metamorphic Development of The Peripheral Auditory System of The Bullfrog, Rana Catesbeiana: An Anatomical and Physiological Study

This thesis is an investigation of the post-metamorphic development of the peripheral auditory system of the bullfrog, Rana catesbeiana. The acoustic responses of single fibers of the VIIIth cranial nerve were studied in juvenile and adult frogs. Three populations of auditory fibers are found in both groups, but there is a downward shift in their best excitatory frequencies (BEFs): low frequency fibers with BEFs from 100-800 Hz in juveniles and 100-400 Hz in adults; intermediate frequency fibers with BEFs from 1000-1700 Hz and 500-900 Hz in juveniles and adults, respectively; high frequency fibers with BEFs broadly distributed from 1800-2500 Hz in juveniles, but centered around 1200-1400 Hz in adults. Low frequency fibers in both groups of frogs exhibit two-tone inhibition, but the distribution of best inhibitory frequencies shifts downward from 1000-1700 Hz in juveniles to 500-900 Hz in adults. The thresholds of excitation are widely distributed in both juveniles and adults ranging from 20-130 dB SPL and from 20-100 dB SPL, respectively.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physiology

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2014

Author dc:creator

• Shofner, William Phillip, Jr.

• Biology, Animal Physiology

Identifier

(UMI)AAI8324645

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/71424