Changes in spontaneous neural activity in the dorsal cochlear nucleus following exposure to intense sound: relation to threshold shift

1998 ◽  
Vol 124 (1-2) ◽  
pp. 78-84 ◽  
Author(s):  
James A Kaltenbach ◽  
Donald A Godfrey ◽  
John B Neumann ◽  
Devin L McCaslin ◽  
Chad E Afman ◽  
...  
Keyword(s):  
Neural Activity ◽  
Cochlear Nucleus ◽  
Dorsal Cochlear Nucleus ◽  
Threshold Shift ◽  
Spontaneous Neural Activity

Cisplatin-induced Increases in Spontaneous Neural Activity in the Dorsal Cochlear Nucleus and Associated Outer Hair Cell Loss

2000 ◽  
Vol 39 (1) ◽  
pp. 24-29 ◽  
Author(s):  
Sarah B. Melamed ◽  
James A. Kaltenbach ◽  
Michael W. Church ◽  
Donald L. Burgio ◽  
Chad E. Afmar
Keyword(s):  
Hair Cell ◽  
Neural Activity ◽  
Cochlear Nucleus ◽  
Outer Hair Cell ◽  
Cell Loss ◽  
Dorsal Cochlear Nucleus ◽  
Hair Cell Loss ◽  
Spontaneous Neural Activity

Cisplatin-Induced Hyperactivity in the Dorsal Cochlear Nucleus and Its Relation to Outer Hair Cell Loss: Relevance to Tinnitus

2002 ◽  
Vol 88 (2) ◽  
pp. 699-714 ◽  
Author(s):  
James A. Kaltenbach ◽  
John D. Rachel ◽  
T. Alecia Mathog ◽  
Jinsheng Zhang ◽  
Pamela R. Falzarano ◽  
...  
Keyword(s):  
Cochlear Nucleus ◽  
Outer Hair Cell ◽  
Cell Loss ◽  
Outer Hair Cells ◽  
Dorsal Cochlear Nucleus ◽  
Spontaneous Neural Activity ◽  
Electrophysiological Recordings ◽  
Significant Damage ◽  
Basal Half ◽  
The Relationship

Cisplatin causes both acute and chronic forms of tinnitus as well as increases in spontaneous neural activity (hyperactivity) in the dorsal cochlear nucleus (DCN) of hamsters. It has been hypothesized that the induction of hyperactivity in the DCN may be a consequence of cisplatin's effects on cochlear outer hair cells (OHCs); however, systematic studies testing this hypothesis have yet to appear in the literature. In the present investigation, the relationship between hyperactivity and OHC loss, induced by cisplatin, was examined in detail. Hamsters received five treatments of cisplatin at doses ranging from 1.5 to 3 mg · kg−1 · day−1, every other day. Beginning 1 mo after initiation of treatment, electrophysiological recordings were carried out on the surface of the DCN to measure spontaneous multiunit activity along a set of coordinates spanning the medial-lateral (tonotopic) axis of the DCN. After recordings, cochleas were removed and studied histologically using a scanning electron microscope. The results revealed that cisplatin-treated animals with little or no loss of OHCs displayed levels of activity similar to those seen in saline-treated controls. In contrast, the majority (75%) of cisplatin-treated animals with severe OHC loss displayed well-developed hyperactivity in the DCN. The induced hyperactivity was seen mainly in the medial (high-frequency) half of the DCN of treated animals. This pattern was consistent with the observation that OHC loss was distributed mainly in the basal half of the cochlea. In several of the animals with severe OHC loss and hyperactivity, there was no significant damage to IHC stereocilia nor any observable irregularities of the reticular lamina that might have interfered with normal IHC function. Hyperactivity was also observed in the DCN of animals showing severe losses of OHCs accompanied by damage to IHCs, although the degree of hyperactivity in these animals was less than in animals with severe OHC loss but intact IHCs. These results support the view that loss of OHC function may be a trigger of tinnitus-related hyperactivity in the DCN and suggest that this hyperactivity may be somewhat offset by damage to IHCs.

scholarly journals Dynamic relationships between spontaneous and evoked electrophysiological activity

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Soren Wainio-Theberge ◽  
Annemarie Wolff ◽  
Georg Northoff
Keyword(s):  
Neural Activity ◽  
Large Scale ◽  
Behavioral Outcomes ◽  
Low Frequencies ◽  
Scale Free ◽  
Non Invasive ◽  
Spontaneous Neural Activity ◽  
Electrophysiological Signals ◽  
Evoked Activity ◽  
Dynamic Relationships

AbstractSpontaneous neural activity fluctuations have been shown to influence trial-by-trial variation in perceptual, cognitive, and behavioral outcomes. However, the complex electrophysiological mechanisms by which these fluctuations shape stimulus-evoked neural activity remain largely to be explored. Employing a large-scale magnetoencephalographic dataset and an electroencephalographic replication dataset, we investigate the relationship between spontaneous and evoked neural activity across a range of electrophysiological variables. We observe that for high-frequency activity, high pre-stimulus amplitudes lead to greater evoked desynchronization, while for low frequencies, high pre-stimulus amplitudes induce larger degrees of event-related synchronization. We further decompose electrophysiological power into oscillatory and scale-free components, demonstrating different patterns of spontaneous-evoked correlation for each component. Finally, we find correlations between spontaneous and evoked time-domain electrophysiological signals. Overall, we demonstrate that the dynamics of multiple electrophysiological variables exhibit distinct relationships between their spontaneous and evoked activity, a result which carries implications for experimental design and analysis in non-invasive electrophysiology.

Sign in / Sign up

Export Citation Format

Share Document