Some relations between the auditory system of the medulla and noise-intensity stimulus functions

Abstract

Thesis (Ph.D.)--Boston UniversityThis study was undertaken to determine the behavioral significance of certain anatomical structures. Lesions were produced in various auditory pathways of animals previously trained to respond to auditory and non-auditory stimuli. Postoperative behavior was compared to preoperative behavior and correlated with neuroanatomical data. On the basis of historical evidence ventral acoustic structures were divided into 3 major pathways. The large fiber pathway originated in the posterior division of the ventral cochlear nucleus, coursed as the large fiber component of the trapezoid body and terminated in the contralateral nucleus of the trapezoid body. The superior olivary pathway arose as collaterals of the large fibers of the trapezoid body coursing dorsally to enter the superior olive. The small fiber pathway arose in the anterior division of the ventral cochlear nucleus, coursed as the small fiber component of the trapezoid body, passed through the superior olive and entered the accessory superior olive of the same side. A portion of the small fibers of the trapezoid body appeared to pass under the superior olive and have been shown to enter the contralateral accessory superior olive [TRUNCATED