Coherence of Visual-Evoked Gamma Oscillations Is Disrupted by Propofol but Preserved Under Equipotent Doses of Isoflurane
Previous research demonstrates that the underlying state of the brain influences how sensory stimuli are processed. Canonically, the state of the brain has been defined by quantifying the spectral characteristics of spontaneous fluctuations in local field potentials (LFP). Here, we utilized isoflura...
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| Format: | Article |
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Frontiers Media S.A.
2019-05-01
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| Series: | Frontiers in Systems Neuroscience |
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| Online Access: | https://www.frontiersin.org/article/10.3389/fnsys.2019.00019/full |
| _version_ | 1818338053369888768 |
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| author | Adeeti Aggarwal Connor Brennan Brenna Shortal Diego Contreras Max B. Kelz Alex Proekt |
| author_facet | Adeeti Aggarwal Connor Brennan Brenna Shortal Diego Contreras Max B. Kelz Alex Proekt |
| author_sort | Adeeti Aggarwal |
| collection | DOAJ |
| description | Previous research demonstrates that the underlying state of the brain influences how sensory stimuli are processed. Canonically, the state of the brain has been defined by quantifying the spectral characteristics of spontaneous fluctuations in local field potentials (LFP). Here, we utilized isoflurane and propofol anesthesia to parametrically alter the spectral state of the murine brain. With either drug, we produce slow wave activity, with low anesthetic doses, or burst suppression, with higher doses. We find that while spontaneous LFP oscillations were similar, the average visual-evoked potential (VEP) was always smaller in amplitude and shorter in duration under propofol than under comparable doses of isoflurane. This diminished average VEP results from increased trial-to-trial variability in VEPs under propofol. One feature of single trial VEPs that was consistent in all animals was visual-evoked gamma band oscillation (20–60 Hz). This gamma band oscillation was coherent between trials in the early phase (<250 ms) of the visual evoked potential under isoflurane. Inter trial phase coherence (ITPC) of gamma oscillations was dramatically attenuated in the same propofol anesthetized mice despite similar spontaneous oscillations in the LFP. This suggests that while both anesthetics lead to loss of consciousness (LOC), elicit slow oscillations and burst suppression, only the isoflurane permits phase resetting of gamma oscillations by visual stimuli. These results demonstrate that accurate characterization of a brain state must include both spontaneous as well as stimulus-induced perturbations of brain activity. |
| first_indexed | 2024-12-13T15:05:00Z |
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| institution | Directory Open Access Journal |
| issn | 1662-5137 |
| language | English |
| last_indexed | 2024-12-13T15:05:00Z |
| publishDate | 2019-05-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Systems Neuroscience |
| spelling | doaj.art-93fafba9be8a48dba09e719f9af1c0c12022-12-21T23:41:01ZengFrontiers Media S.A.Frontiers in Systems Neuroscience1662-51372019-05-011310.3389/fnsys.2019.00019452363Coherence of Visual-Evoked Gamma Oscillations Is Disrupted by Propofol but Preserved Under Equipotent Doses of IsofluraneAdeeti Aggarwal0Connor Brennan1Brenna Shortal2Diego Contreras3Max B. Kelz4Alex Proekt5Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United StatesDepartment of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United StatesDepartment of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United StatesDepartment of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United StatesDepartment of Anesthesiology and Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United StatesDepartment of Anesthesiology and Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United StatesPrevious research demonstrates that the underlying state of the brain influences how sensory stimuli are processed. Canonically, the state of the brain has been defined by quantifying the spectral characteristics of spontaneous fluctuations in local field potentials (LFP). Here, we utilized isoflurane and propofol anesthesia to parametrically alter the spectral state of the murine brain. With either drug, we produce slow wave activity, with low anesthetic doses, or burst suppression, with higher doses. We find that while spontaneous LFP oscillations were similar, the average visual-evoked potential (VEP) was always smaller in amplitude and shorter in duration under propofol than under comparable doses of isoflurane. This diminished average VEP results from increased trial-to-trial variability in VEPs under propofol. One feature of single trial VEPs that was consistent in all animals was visual-evoked gamma band oscillation (20–60 Hz). This gamma band oscillation was coherent between trials in the early phase (<250 ms) of the visual evoked potential under isoflurane. Inter trial phase coherence (ITPC) of gamma oscillations was dramatically attenuated in the same propofol anesthetized mice despite similar spontaneous oscillations in the LFP. This suggests that while both anesthetics lead to loss of consciousness (LOC), elicit slow oscillations and burst suppression, only the isoflurane permits phase resetting of gamma oscillations by visual stimuli. These results demonstrate that accurate characterization of a brain state must include both spontaneous as well as stimulus-induced perturbations of brain activity.https://www.frontiersin.org/article/10.3389/fnsys.2019.00019/fullisofluranepropofolgammaVEPvisual evoked potentialanesthesia |
| spellingShingle | Adeeti Aggarwal Connor Brennan Brenna Shortal Diego Contreras Max B. Kelz Alex Proekt Coherence of Visual-Evoked Gamma Oscillations Is Disrupted by Propofol but Preserved Under Equipotent Doses of Isoflurane Frontiers in Systems Neuroscience isoflurane propofol gamma VEP visual evoked potential anesthesia |
| title | Coherence of Visual-Evoked Gamma Oscillations Is Disrupted by Propofol but Preserved Under Equipotent Doses of Isoflurane |
| title_full | Coherence of Visual-Evoked Gamma Oscillations Is Disrupted by Propofol but Preserved Under Equipotent Doses of Isoflurane |
| title_fullStr | Coherence of Visual-Evoked Gamma Oscillations Is Disrupted by Propofol but Preserved Under Equipotent Doses of Isoflurane |
| title_full_unstemmed | Coherence of Visual-Evoked Gamma Oscillations Is Disrupted by Propofol but Preserved Under Equipotent Doses of Isoflurane |
| title_short | Coherence of Visual-Evoked Gamma Oscillations Is Disrupted by Propofol but Preserved Under Equipotent Doses of Isoflurane |
| title_sort | coherence of visual evoked gamma oscillations is disrupted by propofol but preserved under equipotent doses of isoflurane |
| topic | isoflurane propofol gamma VEP visual evoked potential anesthesia |
| url | https://www.frontiersin.org/article/10.3389/fnsys.2019.00019/full |
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