Local versus global effects of isoflurane anesthesia on visual processing in the fly brain

Cohen, Dror, Zalucki, Oressia H., van Swinderen, Bruno and Tsuchiya, Naotsugu (2016) Local versus global effects of isoflurane anesthesia on visual processing in the fly brain. eNeuro, 3 4: . doi:10.1523/ENEURO.0116-16.2016


Author Cohen, Dror
Zalucki, Oressia H.
van Swinderen, Bruno
Tsuchiya, Naotsugu
Title Local versus global effects of isoflurane anesthesia on visual processing in the fly brain
Journal name eNeuro   Check publisher's open access policy
ISSN 2373-2822
Publication date 2016-07-01
Sub-type Article (original research)
DOI 10.1523/ENEURO.0116-16.2016
Open Access Status Not yet assessed
Volume 3
Issue 4
Total pages 21
Place of publication Washington, DC, United States
Publisher Society for Neuroscience
Language eng
Subject 2700 Medicine
Abstract What characteristics of neural activity distinguish the awake and anesthetized brain? Drugs such as isoflurane abolish behavioral responsiveness in all animals, implying evolutionarily conserved mechanisms. However, it is unclear whether this conservation is reflected at the level of neural activity. Studies in humans have shown that anesthesia is characterized by spatially distinct spectral and coherence signatures that have also been implicated in the global impairment of cortical communication. We questioned whether anesthesia has similar effects on global and local neural processing in one of the smallest brains, that of the fruit fly (Drosophila melanogaster). Using a recently developed multielectrode technique, we recorded local field potentials from different areas of the fly brain simultaneously, while manipulating the concentration of isoflurane. Flickering visual stimuli ('frequency tags') allowed us to track evoked responses in the frequency domain and measure the effects of isoflurane throughout the brain. We found that isoflurane reduced power and coherence at the tagging frequency (13 or 17 Hz) in central brain regions. Unexpectedly, isoflurane increased power and coherence at twice the tag frequency (26 or 34 Hz) in the optic lobes of the fly, but only for specific stimulus configurations. By modeling the periodic responses, we show that the increase in power in peripheral areas can be attributed to local neuroanatomy. We further show that the effects on coherence can be explained by impacted signal-to-noise ratios. Together, our results show that general anesthesia has distinct local and global effects on neuronal processing in the fruit fly brain.
Formatted abstract
What characteristics of neural activity distinguish the awake and anesthetized brain? Drugs such as isoflurane abolish behavioral responsiveness in all animals, implying evolutionarily conserved mechanisms. However, it is unclear whether this conservation is reflected at the level of neural activity. Studies in humans have shown that anesthesia is characterized by spatially distinct spectral and coherence signatures that have also been implicated in the global impairment of cortical communication. We questioned whether anesthesia has similar effects on global and local neural processing in one of the smallest brains, that of the fruit fly (Drosophila melanogaster). Using a recently developed multielectrode technique, we recorded local field potentials from different areas of the fly brain simultaneously, while manipulating the concentration of isoflurane. Flickering visual stimuli (‘frequency tags’) allowed us to track evoked responses in the frequency domain and measure the effects of isoflurane throughout the brain. We found that isoflurane reduced power and coherence at the tagging frequency (13 or 17 Hz) in central brain regions. Unexpectedly, isoflurane increased power and coherence at twice the tag frequency (26 or 34 Hz) in the optic lobes of the fly, but only for specific stimulus configurations. By modeling the periodic responses, we show that the increase in power in peripheral areas can be attributed to local neuroanatomy. We further show that the effects on coherence can be explained by impacted signal-to-noise ratios. Together, our results show that general anesthesia has distinct local and global effects on neuronal processing in the fruit fly brain.
Keyword Anesthesia
Consciousness
Drosophila
Frequency tagging
Isoflurane
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status UQ
Additional Notes Published July/August 2016

Document type: Journal Article
Sub-type: Article (original research)
Collections: HERDC Pre-Audit
Queensland Brain Institute Publications
 
Versions
Version Filter Type
Citation counts: Scopus Citation Count Cited 0 times in Scopus Article
Google Scholar Search Google Scholar
Created: Wed, 30 Nov 2016, 02:02:15 EST by Kirstie Asmussen on behalf of School of Music