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Garrett A, Lannigan V, Yates NJ, Rodger J, Mulders W. Physiological and anatomical investigation of the auditory brainstem in the Fat-tailed dunnart ( Sminthopsis crassicaudata). PeerJ 2019; 7:e7773. [PMID: 31592349 PMCID: PMC6776069 DOI: 10.7717/peerj.7773] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 08/27/2019] [Indexed: 11/20/2022] Open
Abstract
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.
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Affiliation(s)
- Andrew Garrett
- Department of Systems Neuroscience, J.F.B. Institute für Zoologie und Anthropologie, Universität Göttingen, Germany
- School of Biological Sciences, University of Western Australia, Crawley, Western Australia, Australia
| | - Virginia Lannigan
- School of Biological Sciences, University of Western Australia, Crawley, Western Australia, Australia
- School of Human Sciences, M311, University of Western Australia, Crawley, Western Australia, Australia
| | - Nathanael J. Yates
- School of Human Sciences, M311, University of Western Australia, Crawley, Western Australia, Australia
- The Queensland Brain Institute, University of Queensland, St Lucia, Queensland, Australia
| | - Jennifer Rodger
- School of Biological Sciences, University of Western Australia, Crawley, Western Australia, Australia
- School of Human Sciences, M311, University of Western Australia, Crawley, Western Australia, Australia
| | - Wilhelmina Mulders
- School of Human Sciences, M311, University of Western Australia, Crawley, Western Australia, Australia
- Ear Science Institute Australia, Subiaco, Western Australia, Australia
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