scholarly journals Ketamine anaesthesia induces gain enhancement via recurrent excitation in granular input layers of the auditory cortex

2020 ◽  
Vol 598 (13) ◽  
pp. 2741-2755 ◽  
Author(s):  
Katrina E. Deane ◽  
Michael G. K. Brunk ◽  
Andrew W. Curran ◽  
Marina M. Zempeltzi ◽  
Jing Ma ◽  
...  
Keyword(s):  
Auditory Cortex ◽  
Gain Enhancement ◽  
Ketamine Anaesthesia ◽  
Recurrent Excitation

scholarly journals Ketamine anesthesia induces gain enhancement via recurrent excitation in granular input layers of the auditory cortex

2019 ◽  
Author(s):  
Katrina E. Deane ◽  
Michael G. K. Brunk ◽  
Andrew W. Curran ◽  
Marina M. Zempeltzi ◽  
Jing Ma ◽  
...  
Keyword(s):  
Auditory Cortex ◽  
Network Activity ◽  
Anesthetic Agent ◽  
Clinical Effects ◽  
Gabaergic Interneurons ◽  
Mongolian Gerbils ◽  
Gain Enhancement ◽  
Recurrent Excitation ◽  
Input Processing ◽  
Granular Layers

The N-methyl-D-aspartate (NMDA) receptor antagonist, ketamine, is commonly used as an anesthetic agent and has more recently gained attention as an antidepressant. Ketamine has been linked to increased stimulus-locked excitability, inhibition of interneurons, and modulation of intrinsic neuronal oscillations. However, the functional network mechanisms are still elusive. A better understanding of these anesthetic network effects may improve upon previous interpretations of seminal studies conducted under anesthesia and have widespread relevance for neuroscience with awake and anesthetized subjects as well as in medicine. Here, we investigated the effects of anesthetic doses of ketamine (15mg kg−1/h i.p.) on the network activity after pure tone stimulation within the auditory cortex of male Mongolian gerbils (Meriones unguiculatus). We used laminar current source density (CSD) analysis and subsequent layer-specific continuous wavelet analysis to investigate spatiotemporal response dynamics on cortical columnar processing in awake and ketamine-anesthetized animals. We found thalamocortical input processing within granular layers III/IV to be significantly increased under ketamine. This effect on early thalamocortical input processing was not due to changes in cross-trial phase coherence. Rather, the layer-dependent gain enhancement under ketamine was attributed to a broadband increase in amplitude reflecting an increase in recurrent excitation. The time-frequency analysis is further indicative of a prolonged period of stimulus-induced excitation possibly due to a reduced coupling of excitation and inhibition in granular input circuits—in line with the common hypothesis of cortical disinhibition via NMDA-mediated suppression of GABAergic interneurons.Statement of significanceKetamine is a common anesthetic agent and is known to alter excitability and neuronal synchronicity in the cortex. We reveal here that anesthetic doses of ketamine increase recurrent excitation of thalamic input in the granular layers of the auditory cortex of Mongolian gerbils. This leads to a layer-specific gain enhancement of the time-locked response to external stimuli. Analysis of tone-evoked amplitudes and cross-trial variability of cortical current sources and sinks indicate a mechanism of cortical disinhibition via NMDA-mediated suppression of GABAergic interneurons. Our findings might help to understand the functional mechanisms of the clinical effects of ketamine promoting the development of new therapeutic agents with lower side effects.

scholarly journals GABAergic neural activity involved in salicylate-induced auditory cortex gain enhancement

Neuroscience ◽  
2011 ◽  
Vol 189 ◽  
pp. 187-198 ◽  
Author(s):  
J. Lu ◽  
E. Lobarinas ◽  
A. Deng ◽  
R. Goodey ◽  
D. Stolzberg ◽  
...  
Keyword(s):  
Auditory Cortex ◽  
Neural Activity ◽  
Gain Enhancement

Influence of kainic acid and long-lasting intermitent hypoxia on auditory cortex

2005 ◽  
Vol 84 (01) ◽  
Author(s):  
P Benesová ◽  
M Langmeier ◽  
J Betka ◽  
S Trojan
Keyword(s):  
Auditory Cortex ◽  
Kainic Acid

Neural Processing of Octave Illusion in Auditory Cortex Revealed by Frequency Tagging Method

2020 ◽  
Vol 140 (7) ◽  
pp. 762-768
Author(s):  
Yoshiki Aizawa ◽  
Nina Pilyugina ◽  
Akihiko Tsukahara ◽  
Keita Tanaka
Keyword(s):  
Auditory Cortex ◽  
Neural Processing ◽  
Octave Illusion

Design and Analysis of Wideband Dielectric Resonator Antenna with Bandwidth and Gain Enhancement for C-Band Applications

2018 ◽  
Vol 11 (6) ◽  
pp. 352 ◽  
Author(s):  
Sharif Ahmed Qasem ◽  
Tan Kim Geok ◽  
Mohamad Yusoff Alias ◽  
Ferdous Hossain ◽  
Naif Alsowaidi
Keyword(s):  
Dielectric Resonator ◽  
Dielectric Resonator Antenna ◽  
Gain Enhancement

Gain Enhancement for Reflectarray

PIERS Online ◽  
2006 ◽  
Vol 2 (6) ◽  
pp. 601-604
Author(s):  
The-Nan Chang
Keyword(s):  
Gain Enhancement
Sign in / Sign up

Export Citation Format

Share Document