scholarly journals Connections of the auditory brainstem in a songbird,Taeniopygia guttata.II. Projections of nucleus angularis and nucleus laminaris to the superior olive and lateral lemniscal nuclei

2010 ◽  
Vol 518 (11) ◽  
pp. 2135-2148 ◽  
Author(s):  
Nils O.E. Krützfeldt ◽  
Priscilla Logerot ◽  
M. Fabiana Kubke ◽  
J. Martin Wild
Keyword(s):  
Auditory Brainstem ◽  
Nucleus Laminaris ◽  
Superior Olive ◽  
Nucleus Angularis

scholarly journals Connections of the auditory brainstem in a Songbird,Taeniopygia guttata.I. Projections of nucleus angularis and nucleus laminaris to the auditory torus

2010 ◽  
Vol 518 (11) ◽  
pp. 2109-2134 ◽  
Author(s):  
Nils O.E. Krützfeldt ◽  
Priscilla Logerot ◽  
M. Fabiana Kubke ◽  
J. Martin Wild
Keyword(s):  
Auditory Brainstem ◽  
Nucleus Laminaris ◽  
Nucleus Angularis

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

2019 ◽  
Author(s):  
Andrew Garrett ◽  
Virginia Lannigan ◽  
Nathanael Yates ◽  
Jennifer Rodger ◽  
Wilhelmina Mulders
Keyword(s):  
Auditory System ◽  
Mammalian Species ◽  
Auditory Brainstem ◽  
Auditory Brainstem Responses ◽  
Superior Olivary Complex ◽  
Medial Superior Olive ◽  
Superior Olive ◽  
Medial Nucleus ◽  
Sminthopsis Crassicaudata ◽  
Nissl Stain

The fat-tailed Dunnart (Sminthopsis crassicaudata) is a small (10-20g) 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 (5ms) 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.

scholarly journals Auditory brainstem models: adapting cochlear nuclei improve spatial encoding by the medial superior olive in reverberation

2019 ◽  
Author(s):  
Andrew Brughera ◽  
Jason Mikiel-Hunter ◽  
Mathias Dietz ◽  
David McAlpine
Keyword(s):  
Spatial Information ◽  
Interaural Time Difference ◽  
Auditory Pathway ◽  
Auditory Brainstem ◽  
Coincidence Detection ◽  
Type Model ◽  
Medial Superior Olive ◽  
Sound Energy ◽  
Superior Olive ◽  
Cochlear Nuclei

AbstractListeners perceive sound-energy as originating from the direction of its source, even as direct sound is followed milliseconds later by reflected sound from multiple different directions. Early-arriving sound is emphasised in the ascending auditory pathway, including the medial superior olive (MSO) where binaural neurons encode the interaural time difference (ITD) cue for spatial location. Behaviourally, weighting of ITD conveyed during rising sound-energy is stronger at 600 Hz, a frequency with higher reverberant energy, than at 200 Hz where reverberant energy is lower. Here we computationally explore the combined effectiveness of adaptation before ITD-encoding, and excitatory binaural coincidence detection within MSO neurons, in emphasising ITD conveyed in early-arriving sound. With excitatory inputs from adapting model spherical bushy cells (SBCs) of the bilateral cochlear nuclei, a Hodgkin-Huxley-type model MSO neuron reproduces the frequency-dependent emphasis of rising vs. peak sound-energy in ITD-encoding. Maintaining the adaptation in model SBCs, and adjusting membrane speed in model MSO neurons, hemispheric populations of model SBCs and MSO neurons, with simplified membranes for computational efficiency, also reproduce the stronger weighting of ITD information conveyed during rising sound-energy at 600 Hz compared to 200 Hz. This hemispheric model further demonstrates a link between strong weighting of spatial information during rising sound-energy, and correct unambiguous lateralisation of reverberant speech.

scholarly journals Dipolar extracellular potentials generated by axonal projections

2017 ◽  
Author(s):  
Thomas McColgan ◽  
Ji Liu ◽  
Paula T Kuokkanen ◽  
Catherine E Carr ◽  
Hermann Wagner ◽  
...  
Keyword(s):  
Action Potentials ◽  
Brain Regions ◽  
Auditory Brainstem ◽  
Multielectrode Array ◽  
Field Potentials ◽  
Physiological Basis ◽  
Nucleus Laminaris ◽  
Axonal Projections ◽  
Terminal Zone ◽  
Source Of Information

AbstractExtracellular field potentials (EFPs) are an important source of information in neuroscience, but their physiological basis is in many cases still a matter of debate. Axonal sources are typically discounted in modeling and data analysis because their contributions are assumed to be negligible. Here, we show experimentally and theoretically that contributions of axons to EFPs can be significant. Modeling action potentials propagating along axons, we showed that EFPs were prominent in the presence of a terminal zone where axons branch and terminate in close succession, as found in many brain regions. Our models predicted a dipolar far field and a polarity reversal at the center of the terminal zone. We confirmed these predictions using EFPs from the barn owl auditory brainstem where we recorded in nucleus laminaris using a multielectrode array. These results demonstrate that axonal terminal zones produce EFPs with considerable amplitude and spatial reach.

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