Physiological and anatomical investigation of the auditory brainstem in the Fat-tailed dunnart ( Sminthopsis crassicaudata )

PeerJ

article

Andrew Garrett¹  Virginia Lannigan²  Nathanael J. Yates³  Jennifer Rodger²  Wilhelmina Mulders³ 

[1] Department of Systems Neuroscience, J.F.B. Institute für Zoologie und Anthropologie, Universität Göttingen;School of Biological Sciences, University of Western Australia;School of Human Sciences, M311, University of Western Australia;The Queensland Brain Institute, University of Queensland;Ear Science Institute Australia

关键词: Superior olivary nuclei;    Cochlear nucleus;    Marsupial;    Hearing;    Auditory brainstem response;   

DOI  :  10.7717/peerj.7773

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

The fat-tailed dunnart (Sminthopsis crassicaudata) is a small (10–20 g) native marsupial endemic to the south west of Western Australia. Currently little is known about the auditory capabilities of the dunnart, and of marsupials in general. Consequently, this study sought to investigate several electrophysiological and anatomical properties of the dunnart auditory system. Auditory brainstem responses (ABR) were recorded to brief (5 ms) tone pips at a range of frequencies (4–47.5 kHz) and intensities to determine auditory brainstem thresholds. The dunnart ABR displayed multiple distinct peaks at all test frequencies, similar to other mammalian species. ABR showed the dunnart is most sensitive to higher frequencies increasing up to 47.5 kHz. Morphological observations (Nissl stain) revealed that the auditory structures thought to contribute to the first peaks of the ABR were all distinguishable in the dunnart. Structures identified include the dorsal and ventral subdivisions of the cochlear nucleus, including a cochlear nerve root nucleus as well as several distinct nuclei in the superior olivary complex, such as the medial nucleus of the trapezoid body, lateral superior olive and medial superior olive. This study is the first to show functional and anatomical aspects of the lower part of the auditory system in the Fat-tailed dunnart.

【 授权许可】

CC BY