Physiology of pathway from dorsal cochlear nucleus to inferior colliculus revealed by electrical and auditory stimulation

1980 ◽  
Vol 41 (1) ◽  
Author(s):  
M.N. Semple ◽  
L.M. Aitkin
Keyword(s):  
Inferior Colliculus ◽  
Cochlear Nucleus ◽  
Auditory Stimulation ◽  
Dorsal Cochlear Nucleus

scholarly journals Noise-induced hyperactivity in the inferior colliculus: its relationship with hyperactivity in the dorsal cochlear nucleus

2012 ◽  
Vol 108 (4) ◽  
pp. 976-988 ◽  
Author(s):  
N. F. Manzoor ◽  
F. G. Licari ◽  
M. Klapchar ◽  
R. L. Elkin ◽  
Y. Gao ◽  
...  
Keyword(s):  
Spontaneous Activity ◽  
Inferior Colliculus ◽  
Cochlear Nucleus ◽  
Time Course ◽  
Noise Exposure ◽  
Dorsal Cochlear Nucleus ◽  
Control Group ◽  
Before And After ◽  
Intense Noise ◽  
And Control

Intense noise exposure causes hyperactivity to develop in the mammalian dorsal cochlear nucleus (DCN) and inferior colliculus (IC). It has not yet been established whether the IC hyperactivity is driven by hyperactivity from extrinsic sources that include the DCN or instead is maintained independently of this input. We have investigated the extent to which IC hyperactivity is dependent on input from the contralateral DCN by comparing recordings of spontaneous activity in the IC of noise-exposed and control hamsters before and after ablation of the contralateral DCN. One group of animals was binaurally exposed to intense sound (10 kHz, 115 dB SPL, 4 h), whereas the control group was not. Both groups were studied electrophysiologically 2–3 wk later by first mapping spontaneous activity along the tonotopic axis of the IC to confirm induction of hyperactivity. Spontaneous activity was then recorded at a hyperactive IC locus over two 30-min periods, one with DCNs intact and the other after ablation of the contralateral DCN. In a subset of animals, activity was again mapped along the tonotopic axis after the time course of the activity was recorded before and after DCN ablation. Following recordings, the brains were fixed, and histological evaluations were performed to assess the extent of DCN ablation. Ablation of the DCN resulted in major reductions of IC hyperactivity. Levels of postablation activity in exposed animals were similar to the levels of activity in the IC of control animals, indicating an almost complete loss of hyperactivity in exposed animals. The results suggest that hyperactivity in the IC is dependent on support from extrinsic sources that include and may even begin with the DCN. This finding does not rule out longer term compensatory or homeostatic adjustments that might restore hyperactivity in the IC over time.

The spatial representation of frequency in the rat dorsal cochlear nucleus and inferior colliculus

1988 ◽  
Vol 36 (2-3) ◽  
pp. 181-189 ◽  
Author(s):  
Allen F Ryan ◽  
Zabrina Furlow ◽  
Nigel K Woolf ◽  
Elizabeth M Keithley
Keyword(s):  
Inferior Colliculus ◽  
Cochlear Nucleus ◽  
Spatial Representation ◽  
Dorsal Cochlear Nucleus

scholarly journals A novel class of inferior colliculus principal neurons labeled in vasoactive intestinal peptide-Cre mice

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
David Goyer ◽  
Marina A Silveira ◽  
Alexander P George ◽  
Nichole L Beebe ◽  
Ryan M Edelbrock ◽  
...  
Keyword(s):  
Inferior Colliculus ◽  
Vasoactive Intestinal Peptide ◽  
Speech Processing ◽  
Cochlear Nucleus ◽  
Temporal Integration ◽  
Brain Regions ◽  
Auditory Brainstem ◽  
Dorsal Cochlear Nucleus ◽  
Multifaceted Approach ◽  
Inhibitory Circuits

Located in the midbrain, the inferior colliculus (IC) is the hub of the central auditory system. Although the IC plays important roles in speech processing, sound localization, and other auditory computations, the organization of the IC microcircuitry remains largely unknown. Using a multifaceted approach in mice, we have identified vasoactive intestinal peptide (VIP) neurons as a novel class of IC principal neurons. VIP neurons are glutamatergic stellate cells with sustained firing patterns. Their extensive axons project to long-range targets including the auditory thalamus, auditory brainstem, superior colliculus, and periaqueductal gray. Using optogenetic circuit mapping, we found that VIP neurons integrate input from the contralateral IC and the dorsal cochlear nucleus. The dorsal cochlear nucleus also drove feedforward inhibition to VIP neurons, indicating that inhibitory circuits within the IC shape the temporal integration of ascending inputs. Thus, VIP neurons are well-positioned to influence auditory computations in a number of brain regions.

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