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Dejean C, Dupont T, Verpy E, Gonçalves N, Coqueran S, Michalski N, Pucheu S, Bourgeron T, Gourévitch B. Detecting Central Auditory Processing Disorders in Awake Mice. Brain Sci 2023; 13:1539. [PMID: 38002499 PMCID: PMC10669832 DOI: 10.3390/brainsci13111539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 10/24/2023] [Accepted: 10/28/2023] [Indexed: 11/26/2023] Open
Abstract
Mice are increasingly used as models of human-acquired neurological or neurodevelopmental conditions, such as autism, schizophrenia, and Alzheimer's disease. All these conditions involve central auditory processing disorders, which have been little investigated despite their potential for providing interesting insights into the mechanisms behind such disorders. Alterations of the auditory steady-state response to 40 Hz click trains are associated with an imbalance between neuronal excitation and inhibition, a mechanism thought to be common to many neurological disorders. Here, we demonstrate the value of presenting click trains at various rates to mice with chronically implanted pins above the inferior colliculus and the auditory cortex for obtaining easy, reliable, and long-lasting access to subcortical and cortical complex auditory processing in awake mice. Using this protocol on a mutant mouse model of autism with a defect of the Shank3 gene, we show that the neural response is impaired at high click rates (above 60 Hz) and that this impairment is visible subcortically-two results that cannot be obtained with classical protocols for cortical EEG recordings in response to stimulation at 40 Hz. These results demonstrate the value and necessity of a more complete investigation of central auditory processing disorders in mouse models of neurological or neurodevelopmental disorders.
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Affiliation(s)
- Camille Dejean
- Institut Pasteur, Université Paris Cité, INSERM, Institut de l’Audition, Plasticity of Central Auditory Circuits, F-75012 Paris, France
- Cilcare Company, F-34080 Montpellier, France
- Sorbonne Université, Ecole Doctorale Complexité du Vivant, F-75005 Paris, France
| | - Typhaine Dupont
- Institut Pasteur, Université Paris Cité, INSERM, Institut de l’Audition, Plasticity of Central Auditory Circuits, F-75012 Paris, France
| | - Elisabeth Verpy
- Institut Pasteur, Université Paris Cité, CNRS, IUF, Human Genetics and Cognitive Functions, F-75015 Paris, France
| | - Noémi Gonçalves
- Institut Pasteur, Université Paris Cité, INSERM, Institut de l’Audition, Plasticity of Central Auditory Circuits, F-75012 Paris, France
| | - Sabrina Coqueran
- Institut Pasteur, Université Paris Cité, CNRS, IUF, Human Genetics and Cognitive Functions, F-75015 Paris, France
| | - Nicolas Michalski
- Institut Pasteur, Université Paris Cité, INSERM, Institut de l’Audition, Plasticity of Central Auditory Circuits, F-75012 Paris, France
| | | | - Thomas Bourgeron
- Institut Pasteur, Université Paris Cité, CNRS, IUF, Human Genetics and Cognitive Functions, F-75015 Paris, France
| | - Boris Gourévitch
- Institut Pasteur, Université Paris Cité, INSERM, Institut de l’Audition, Plasticity of Central Auditory Circuits, F-75012 Paris, France
- CNRS, F-75016 Paris, France
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2
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Marmelshtein A, Eckerling A, Hadad B, Ben-Eliyahu S, Nir Y. Sleep-like changes in neural processing emerge during sleep deprivation in early auditory cortex. Curr Biol 2023:S0960-9822(23)00773-X. [PMID: 37385257 DOI: 10.1016/j.cub.2023.06.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 03/30/2023] [Accepted: 06/07/2023] [Indexed: 07/01/2023]
Abstract
Insufficient sleep is commonplace in modern lifestyle and can lead to grave outcomes, yet the changes in neuronal activity accumulating over hours of extended wakefulness remain poorly understood. Specifically, which aspects of cortical processing are affected by sleep deprivation (SD), and whether they also affect early sensory regions, remain unclear. Here, we recorded spiking activity in the rat auditory cortex along with polysomnography while presenting sounds during SD followed by recovery sleep. We found that frequency tuning, onset responses, and spontaneous firing rates were largely unaffected by SD. By contrast, SD decreased entrainment to rapid (≥20 Hz) click trains, increased population synchrony, and increased the prevalence of sleep-like stimulus-induced silent periods, even when ongoing activity was similar. Recovery NREM sleep was associated with similar effects as SD with even greater magnitude, while auditory processing during REM sleep was similar to vigilant wakefulness. Our results show that processes akin to those in NREM sleep invade the activity of cortical circuits during SD, even in the early sensory cortex.
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Affiliation(s)
- Amit Marmelshtein
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel; Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Anabel Eckerling
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel; School of Psychological Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Barak Hadad
- School of Electrical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Shamgar Ben-Eliyahu
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel; School of Psychological Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Yuval Nir
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel; Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel; Department of Biomedical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv 6997801, Israel; The Sieratzki-Sagol Center for Sleep Medicine, Tel Aviv Sourasky Medical Center, Tel Aviv 6423906, Israel.
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3
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Manohar S, Chen GD, Li L, Liu X, Salvi R. Chronic stress induced loudness hyperacusis, sound avoidance and auditory cortex hyperactivity. Hear Res 2023; 431:108726. [PMID: 36905854 DOI: 10.1016/j.heares.2023.108726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 02/22/2023] [Accepted: 02/28/2023] [Indexed: 03/06/2023]
Abstract
Hyperacusis, a debilitating loudness intolerance disorder, has been linked to chronic stress and adrenal insufficiency. To investigate the role of chronic stress, rats were chronically treated with corticosterone (CORT) stress hormone. Chronic CORT produced behavioral evidence of loudness hyperacusis, sound avoidance hyperacusis, and abnormal temporal integration of loudness. CORT treatment did not disrupt cochlear or brainstem function as reflected by normal distortion product otoacoustic emissions, compound action potentials, acoustic startle reflexex, and auditory brainstem responses. In contrast, the evoked response from the auditory cortex was enhanced up to three fold after CORT treatment. This hyperactivity was associated with a significant increase in glucocorticoid receptors in auditory cortex layers II/III and VI. Basal serum CORT levels remained normal after chronic CORT stress whereas reactive serum CORT levels evoked by acute restraint stress were blunted (reduced) after chronic CORT stress; similar changes were observed after chronic, intense noise stress. Taken together, our results show for the first time that chronic stress can induce hyperacusis and sound avoidance. A model is proposed in which chronic stress creates a subclinical state of adrenal insufficiency that establishes the necessary conditions for inducing hyperacusis.
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Affiliation(s)
- Senthilvelan Manohar
- Center for Hearing and Deafness, 137 Cary Hall, University at Buffalo, Buffalo, NY 14214, USA
| | - Guang-Di Chen
- Center for Hearing and Deafness, 137 Cary Hall, University at Buffalo, Buffalo, NY 14214, USA
| | - Li Li
- Center for Hearing and Deafness, 137 Cary Hall, University at Buffalo, Buffalo, NY 14214, USA
| | - Xiaopeng Liu
- Center for Hearing and Deafness, 137 Cary Hall, University at Buffalo, Buffalo, NY 14214, USA
| | - Richard Salvi
- Center for Hearing and Deafness, 137 Cary Hall, University at Buffalo, Buffalo, NY 14214, USA.
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Nourmohammadi A, Swift JR, de Pesters A, Guay CS, Adamo MA, Dalfino JC, Ritaccio AL, Schalk G, Brunner P. Passive functional mapping of receptive language cortex during general anesthesia using electrocorticography. Clin Neurophysiol 2023; 147:31-44. [PMID: 36634533 PMCID: PMC10267852 DOI: 10.1016/j.clinph.2022.11.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Revised: 09/30/2022] [Accepted: 11/10/2022] [Indexed: 12/24/2022]
Abstract
OBJECTIVE To investigate the feasibility of passive functional mapping in the receptive language cortex during general anesthesia using electrocorticographic (ECoG) signals. METHODS We used subdurally placed ECoG grids to record cortical responses to speech stimuli during awake and anesthesia conditions. We identified the cortical areas with significant responses to the stimuli using the spectro-temporal consistency of the brain signal in the broadband gamma (BBG) frequency band (70-170 Hz). RESULTS We found that ECoG BBG responses during general anesthesia effectively identify cortical regions associated with receptive language function. Our analyses demonstrated that the ability to identify receptive language cortex varies across different states and depths of anesthesia. We confirmed these results by comparing them to receptive language areas identified during the awake condition. Quantification of these results demonstrated an average sensitivity and specificity of passive language mapping during general anesthesia to be 49±7.7% and 100%, respectively. CONCLUSION Our results demonstrate that mapping receptive language cortex in patients during general anesthesia is feasible. SIGNIFICANCE Our proposed protocol could greatly expand the population of patients that can benefit from passive language mapping techniques, and could eliminate the risks associated with electrocortical stimulation during an awake craniotomy.
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Affiliation(s)
- Amin Nourmohammadi
- National Center for Adaptive Neurotechnologies, Washington University School of Medicine, St. Louis, MO, USA; Department of Neurosurgery, Washington University School of Medicine, St. Louis, MO, USA; Department of Biomedical Sciences, State University of New York at Albany, Albany, NY, USA.
| | - James R Swift
- National Center for Adaptive Neurotechnologies, Washington University School of Medicine, St. Louis, MO, USA; Department of Neurosurgery, Washington University School of Medicine, St. Louis, MO, USA; Department of Biomedical Sciences, State University of New York at Albany, Albany, NY, USA.
| | - Adriana de Pesters
- National Center for Adaptive Neurotechnologies, Washington University School of Medicine, St. Louis, MO, USA; Department of Biomedical Sciences, State University of New York at Albany, Albany, NY, USA.
| | - Christian S Guay
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, USA.
| | - Matthew A Adamo
- Department of Neurosurgery, Albany Medical College, Albany, NY, USA.
| | - John C Dalfino
- Department of Neurosurgery, Albany Medical College, Albany, NY, USA.
| | - Anthony L Ritaccio
- Department of Neurology, Albany Medical College, Albany, NY, USA; Department of Neurology, Mayo Clinic, Jacksonville, FL, USA.
| | - Gerwin Schalk
- National Center for Adaptive Neurotechnologies, Washington University School of Medicine, St. Louis, MO, USA; Department of Biomedical Sciences, State University of New York at Albany, Albany, NY, USA; Chen Frontier Lab for Applied Neurotechnology, Tianqiao and Chrissy Chen Institute, Shanghai, P.R. China.
| | - Peter Brunner
- National Center for Adaptive Neurotechnologies, Washington University School of Medicine, St. Louis, MO, USA; Department of Neurosurgery, Washington University School of Medicine, St. Louis, MO, USA; Department of Biomedical Sciences, State University of New York at Albany, Albany, NY, USA; Department of Neurology, Albany Medical College, Albany, NY, USA.
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5
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Middlebrooks JC, Javier-Tolentino LK, Arneja A, Richardson ML. High Spectral and Temporal Acuity in Primary Auditory Cortex of Awake Cats. J Assoc Res Otolaryngol 2023; 24:197-215. [PMID: 36795196 PMCID: PMC10121981 DOI: 10.1007/s10162-023-00890-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 01/20/2023] [Indexed: 02/17/2023] Open
Abstract
Most accounts of single- and multi-unit responses in auditory cortex under anesthetized conditions have emphasized V-shaped frequency tuning curves and low-pass sensitivity to rates of repeated sounds. In contrast, single-unit recordings in awake marmosets also show I-shaped and O-shaped response areas having restricted tuning to frequency and (for O units) sound level. That preparation also demonstrates synchrony to moderate click rates and representation of higher click rates by spike rates of non-synchronized tonic responses, neither of which are commonly seen in anesthetized conditions. The spectral and temporal representation observed in the marmoset might reflect special adaptations of that species, might be due to single- rather than multi-unit recording, or might indicate characteristics of awake-versus-anesthetized recording conditions. We studied spectral and temporal representation in the primary auditory cortex of alert cats. We observed V-, I-, and O-shaped response areas like those demonstrated in awake marmosets. Neurons could synchronize to click trains at rates about an octave higher than is usually seen with anesthesia. Representations of click rates by rates of non-synchronized tonic responses exhibited dynamic ranges that covered the entire range of tested click rates. The observation of these spectral and temporal representations in cats demonstrates that they are not unique to primates and, indeed, might be widespread among mammalian species. Moreover, we observed no significant difference in stimulus representation between single- and multi-unit recordings. It appears that the principal factor that has hindered observations of high spectral and temporal acuity in the auditory cortex has been the use of general anesthesia.
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Affiliation(s)
- John C Middlebrooks
- Department of Otolaryngology, University of California at Irvine, D404 Medical Science D, Irvine, CA, 92697-5310, USA.
- Department of Neurobiology and Behavior, University of California at Irvine, Irvine, CA, USA.
- Department of Cognitive Sciences, University of California at Irvine, Irvine, CA, USA.
- Center for Hearing Research, University of California at Irvine, Irvine, CA, USA.
| | - Lauren K Javier-Tolentino
- Department of Neurobiology and Behavior, University of California at Irvine, Irvine, CA, USA
- Center for Hearing Research, University of California at Irvine, Irvine, CA, USA
| | - Akshat Arneja
- Department of Cognitive Sciences, University of California at Irvine, Irvine, CA, USA
- Center for Hearing Research, University of California at Irvine, Irvine, CA, USA
| | - Matthew L Richardson
- Department of Otolaryngology, University of California at Irvine, D404 Medical Science D, Irvine, CA, 92697-5310, USA
- Center for Hearing Research, University of California at Irvine, Irvine, CA, USA
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6
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Shani-Narkiss H, Beniaguev D, Segev I, Mizrahi A. Stability and flexibility of odor representations in the mouse olfactory bulb. Front Neural Circuits 2023; 17:1157259. [PMID: 37151358 PMCID: PMC10157098 DOI: 10.3389/fncir.2023.1157259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 03/27/2023] [Indexed: 05/09/2023] Open
Abstract
Dynamic changes in sensory representations have been basic tenants of studies in neural coding and plasticity. In olfaction, relatively little is known about the dynamic range of changes in odor representations under different brain states and over time. Here, we used time-lapse in vivo two-photon calcium imaging to describe changes in odor representation by mitral cells, the output neurons of the mouse olfactory bulb. Using anesthetics as a gross manipulation to switch between different brain states (wakefulness and under anesthesia), we found that odor representations by mitral cells undergo significant re-shaping across states but not over time within state. Odor representations were well balanced across the population in the awake state yet highly diverse under anesthesia. To evaluate differences in odor representation across states, we used linear classifiers to decode odor identity in one state based on training data from the other state. Decoding across states resulted in nearly chance-level accuracy. In contrast, repeating the same procedure for data recorded within the same state but in different time points, showed that time had a rather minor impact on odor representations. Relative to the differences across states, odor representations remained stable over months. Thus, single mitral cells can change dynamically across states but maintain robust representations across months. These findings have implications for sensory coding and plasticity in the mammalian brain.
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Affiliation(s)
- Haran Shani-Narkiss
- The Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - David Beniaguev
- The Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Idan Segev
- The Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
- Department of Neurobiology, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Adi Mizrahi
- The Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
- Department of Neurobiology, The Hebrew University of Jerusalem, Jerusalem, Israel
- *Correspondence: Adi Mizrahi,
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7
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Bergman L, Krom AJ, Sela Y, Marmelshtein A, Hayat H, Regev N, Nir Y. Propofol anesthesia concentration rather than abrupt behavioral unresponsiveness linearly degrades responses in the rat primary auditory cortex. Cereb Cortex 2022; 32:5005-5019. [PMID: 35169834 DOI: 10.1093/cercor/bhab528] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 12/16/2021] [Accepted: 12/17/2021] [Indexed: 12/27/2022] Open
Abstract
Despite extensive knowledge of its molecular and cellular effects, how anesthesia affects sensory processing remains poorly understood. In particular, it remains unclear whether anesthesia modestly or robustly degrades activity in primary sensory regions, and whether such changes are linked to anesthesia drug concentration versus behavioral unresponsiveness, which are typically confounded. Here, we used slow gradual intravenous propofol anesthesia induction together with auditory stimulation and intermittent assessment of behavioral responsiveness while recording epidural electroencephalogram, and neuronal spiking activity in primary auditory cortex (PAC) of eight rats. We found that all main components of neuronal activity including spontaneous firing rates, onset response magnitudes, onset response latencies, postonset neuronal silence duration, late-locking to 40 Hz click-trains, and offset responses, gradually changed in a dose-dependent manner with increasing anesthesia levels without showing abrupt shifts around loss of righting reflex or other time-points. Thus, the dominant factor affecting PAC responses is the anesthesia drug concentration rather than any sudden, dichotomous behavioral state changes. Our findings explain a wide array of seemingly conflicting results in the literature that, depending on the precise definition of wakefulness (vigilant vs. drowsy) and anesthesia (light vs. deep/surgical), report a spectrum of effects in primary regions ranging from minimal to dramatic differences.
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Affiliation(s)
- Lottem Bergman
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel.,Department of Neurosurgery, Tel Aviv Sourasky Medical Center, Tel Aviv 6423906, Israel
| | - Aaron J Krom
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel.,Department of Anesthesiology and Critical Care Medicine, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem 91120, Israel.,Department of Anesthesiology and Critical Care Medicine, Hadassah Medical Organization, Jerusalem 91120, Israel
| | - Yaniv Sela
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Amit Marmelshtein
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Hanna Hayat
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Noa Regev
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Yuval Nir
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel.,Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel.,The Sieratzki-Sagol Center for Sleep Medicine, Tel Aviv Sourasky Medical Center, Tel Aviv 6423906, Israel.,Department of Biomedical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv 6997801, Israel
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8
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Filipchuk A, Schwenkgrub J, Destexhe A, Bathellier B. Awake perception is associated with dedicated neuronal assemblies in the cerebral cortex. Nat Neurosci 2022; 25:1327-1338. [PMID: 36171431 PMCID: PMC9534770 DOI: 10.1038/s41593-022-01168-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 08/18/2022] [Indexed: 12/05/2022]
Abstract
Neural activity in the sensory cortex combines stimulus responses and ongoing activity, but it remains unclear whether these reflect the same underlying dynamics or separate processes. In the present study, we show in mice that, during wakefulness, the neuronal assemblies evoked by sounds in the auditory cortex and thalamus are specific to the stimulus and distinct from the assemblies observed in ongoing activity. By contrast, under three different anesthetics, evoked assemblies are indistinguishable from ongoing assemblies in the cortex. However, they remain distinct in the thalamus. A strong remapping of sensory responses accompanies this dynamic state change produced by anesthesia. Together, these results show that the awake cortex engages dedicated neuronal assemblies in response to sensory inputs, which we suggest is a network correlate of sensory perception. Filipchuk et al. show that when awake mice perceive sounds, the auditory cortex produces sound-specific neuronal assemblies distinct from its ongoing activity, whereas under anesthesia sound-evoked assemblies are indistinguishable from ongoing activity.
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Affiliation(s)
- Anton Filipchuk
- Paris-Saclay University, CNRS, Paris-Saclay Institute of Neuroscience, Saclay, France.,Healthy Mind, Institut du Cerveau - ICM, Paris, France
| | - Joanna Schwenkgrub
- Institut Pasteur, Université de Paris, INSERM, Institut de l'Audition, Paris, France
| | - Alain Destexhe
- Paris-Saclay University, CNRS, Paris-Saclay Institute of Neuroscience, Saclay, France.
| | - Brice Bathellier
- Paris-Saclay University, CNRS, Paris-Saclay Institute of Neuroscience, Saclay, France. .,Institut Pasteur, Université de Paris, INSERM, Institut de l'Audition, Paris, France.
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9
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Postal O, Bakay W, Dupont T, Buck A, Élodie Daoud, Petit C, Michalski N, Gourévitch B. Characterizing subcutaneous cortical auditory evoked potentials in mice. Hear Res 2022; 422:108566. [PMID: 35863162 DOI: 10.1016/j.heares.2022.108566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 06/17/2022] [Accepted: 06/30/2022] [Indexed: 11/18/2022]
Abstract
Auditory Brainstem Responses (ABRs) are a reliably robust measure of auditory thresholds in the mammalian hearing system and can be used to determine deficits in the auditory periphery. However, because these measures are limited to the lower stages of the auditory pathway, they are insensitive to changes or deficits that occur in the thalamic and cortical regions. Cortical Auditory Evoked Potentials (CAEPs), as longer latency responses, capture information from these regions. However they are less frequently used as a diagnostic tool, particularly in rodent models, due to their inherent variability and subsequent difficult interpretation. The purpose of this study was to develop a consistent measure of subcutaneous CAEPs to auditory stimuli in mice and to determine their origin. To this end, we investigated the effect on the CAEPs recorded in response to different stimuli (noise, click, and tone (16 kHz) bursts), stimulus presentation rates (2/s, 6/s, 10/s) and electrode placements. Recordings were examined for robust CAEP components to determine the optimal experimental paradigm. We argue that CAEPs can measure robust and replicable cortical responses. Furthermore, by deactivating the auditory cortex with lidocaine we demonstrated that the contralateral cortex is the main contributor to the CAEP. Thus CAEP measurements could prove to be of value diagnostically in future for deficits in higher auditory areas.
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Affiliation(s)
- Olivier Postal
- Institut de l'Audition, Institut Pasteur, INSERM, Université Paris Cité, F-75012 Paris, France; Sorbonne Université, Collège Doctoral, F-75005 Paris, France
| | - Warren Bakay
- Institut de l'Audition, Institut Pasteur, INSERM, Université Paris Cité, F-75012 Paris, France
| | - Typhaine Dupont
- Institut de l'Audition, Institut Pasteur, INSERM, Université Paris Cité, F-75012 Paris, France
| | - Alexa Buck
- Institut de l'Audition, Institut Pasteur, INSERM, Université Paris Cité, F-75012 Paris, France
| | - Élodie Daoud
- Institut de l'Audition, Institut Pasteur, INSERM, Université Paris Cité, F-75012 Paris, France
| | - Christine Petit
- Institut de l'Audition, Institut Pasteur, INSERM, Université Paris Cité, F-75012 Paris, France
| | - Nicolas Michalski
- Institut de l'Audition, Institut Pasteur, INSERM, Université Paris Cité, F-75012 Paris, France
| | - Boris Gourévitch
- Institut de l'Audition, Institut Pasteur, INSERM, Université Paris Cité, F-75012 Paris, France; CNRS, France.
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10
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Zhang R, Zhuang C, Wang Z, Xiao G, Chen K, Li H, Tong L, Mi W, Xie H, Cao J. Simultaneous Observation of Mouse Cortical and Hippocampal Neural Dynamics under Anesthesia through a Cranial Microprism Window. BIOSENSORS 2022; 12:bios12080567. [PMID: 35892463 PMCID: PMC9332076 DOI: 10.3390/bios12080567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 07/20/2022] [Accepted: 07/24/2022] [Indexed: 11/17/2022]
Abstract
The fluorescence microscope has been widely used to explore dynamic processes in vivo in mouse brains, with advantages of a large field-of-view and high spatiotemporal resolution. However, owing to background light and tissue scattering, the single-photon wide-field microscope fails to record dynamic neural activities in the deep brain. To achieve simultaneous imaging of deep-brain regions and the superficial cortex, we combined the extended-field-of-view microscopy previously proposed with a novel prism-based cranial window to provide a longitudinal view. As well as a right-angle microprism for imaging above 1 mm, we also designed a new rectangular-trapezoidal microprism cranial window to extend the depth of observation to 1.5 mm and to reduce brain injury. We validated our method with structural imaging of microglia cells in the superficial cortex and deep-brain regions. We also recorded neuronal activity from the mouse brains in awake and anesthesitized states. The results highlight the great potential of our methods for simultaneous dynamic imaging in the superficial and deep layers of mouse brains.
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Affiliation(s)
- Rujin Zhang
- Department of Anesthesiology, The First Medical Center, Chinese PLA General Hospital, Beijing 100853, China; (R.Z.); (Z.W.); (K.C.); (H.L.); (L.T.); (W.M.)
| | - Chaowei Zhuang
- Department of Automation, Tsinghua University, Beijing 100084, China; (C.Z.); (G.X.)
| | - Zilin Wang
- Department of Anesthesiology, The First Medical Center, Chinese PLA General Hospital, Beijing 100853, China; (R.Z.); (Z.W.); (K.C.); (H.L.); (L.T.); (W.M.)
| | - Guihua Xiao
- Department of Automation, Tsinghua University, Beijing 100084, China; (C.Z.); (G.X.)
| | - Kunsha Chen
- Department of Anesthesiology, The First Medical Center, Chinese PLA General Hospital, Beijing 100853, China; (R.Z.); (Z.W.); (K.C.); (H.L.); (L.T.); (W.M.)
| | - Hao Li
- Department of Anesthesiology, The First Medical Center, Chinese PLA General Hospital, Beijing 100853, China; (R.Z.); (Z.W.); (K.C.); (H.L.); (L.T.); (W.M.)
| | - Li Tong
- Department of Anesthesiology, The First Medical Center, Chinese PLA General Hospital, Beijing 100853, China; (R.Z.); (Z.W.); (K.C.); (H.L.); (L.T.); (W.M.)
| | - Weidong Mi
- Department of Anesthesiology, The First Medical Center, Chinese PLA General Hospital, Beijing 100853, China; (R.Z.); (Z.W.); (K.C.); (H.L.); (L.T.); (W.M.)
| | - Hao Xie
- Department of Automation, Tsinghua University, Beijing 100084, China; (C.Z.); (G.X.)
- Correspondence: (H.X.); (J.C.)
| | - Jiangbei Cao
- Department of Anesthesiology, The First Medical Center, Chinese PLA General Hospital, Beijing 100853, China; (R.Z.); (Z.W.); (K.C.); (H.L.); (L.T.); (W.M.)
- Correspondence: (H.X.); (J.C.)
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11
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Huang B, Yan L, Li Y, Liu W, Liu M, Xiao Z, Huang J. Urethane Improves the Response of Auditory Neurons to Tone. Front Cell Neurosci 2022; 16:855968. [PMID: 35783092 PMCID: PMC9240349 DOI: 10.3389/fncel.2022.855968] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Accepted: 05/12/2022] [Indexed: 11/21/2022] Open
Abstract
Urethane has little effect on nervous system and is often used in neuroscience studies. However, the effect of urethane in neurons is not thoroughly clear. In this study, we investigated changes in neuron responses to tones in inferior colliculus during urethane anesthesia. As urethane was metabolized, the best and characteristic frequencies did not obviously change, but the minimal threshold (MT) remained relatively stable or was elevated. The frequency tuning bandwidth at 60 dB SPL (BW60dBSPL) remained unchanged or decreased, and the average evoked spike of effective frequencies at 60 dB SPL (ES60dBSPL) gradually decreased. Although the average evoked spike of effective frequencies at a tone intensity of 20 dB SPL above MT (ES20dBSPLaboveMT) decreased, the frequency tuning bandwidth at a tone intensity of 20 dB SPL above MT (BW20dBSPLaboveMT) did not change. In addition, the changes in MT, ES60dBSPL, BW60dBSPL, and ES20dBSPLaboveMT increased with the MT in pre-anesthesia awake state (MTpre−anesthesiaawake). In some neurons, the MT was lower, BW60dBSPL was broader, and ES60dBSPL and ES20dBSPLaboveMT were higher in urethane anesthesia state than in pre-anesthesia awake state. During anesthesia, the inhibitory effect of urethane reduced the ES20dBSPLaboveMT, but did not change the MT, characteristic frequency, or BW20dBSPLaboveMT. In the recording session with the strongest neuron response, the first spike latency did not decrease, and the spontaneous spike did not increase. Therefore, we conclude that urethane can reduce/not change the MT, increase the evoked spike, or broaden/not change the frequency tuning range, and eventually improve the response of auditory neurons to tone with or without “pushing down” the tonal receptive field in thresholding model. The improved effect increases with the MTpre−anesthesiaawake of neurons. The changes induced by the inhibitory and improved effects of urethane abide by similar regularities, but the change directions are contrary. The improvement mechanism may be likely due to the increase in the ratio of excitatory/inhibitory postsynaptic inputs to neurons.
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Affiliation(s)
- Bowan Huang
- Department of Physiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
- Department of Anesthesiology, Shenzhen Traditional Chinese Medicine Hospital, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen, China
| | - Linqing Yan
- Department of Physiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Yan Li
- Department of Physiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Wenhui Liu
- The Seventh Affiliated Hospital, Southern Medical University, Foshan, China
| | - Manhua Liu
- The Seventh Affiliated Hospital, Southern Medical University, Foshan, China
| | - Zhongju Xiao
- Department of Physiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
- The Seventh Affiliated Hospital, Southern Medical University, Foshan, China
- *Correspondence: Zhongju Xiao
| | - Jinping Huang
- The Seventh Affiliated Hospital, Southern Medical University, Foshan, China
- Jinping Huang
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12
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Cappotto D, Kang H, Li K, Melloni L, Schnupp J, Auksztulewicz R. Simultaneous mnemonic and predictive representations in the auditory cortex. Curr Biol 2022; 32:2548-2555.e5. [PMID: 35487221 DOI: 10.1016/j.cub.2022.04.022] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 03/03/2022] [Accepted: 04/08/2022] [Indexed: 11/26/2022]
Abstract
Recent studies have shown that stimulus history can be decoded via the use of broadband sensory impulses to reactivate mnemonic representations.1-4. However, memories of previous stimuli can also be used to form sensory predictions about upcoming stimuli.5,6 Predictive mechanisms allow the brain to create a probable model of the outside world, which can be updated when errors are detected between the model predictions and external inputs. 7-10 Direct recordings in the auditory cortex of awake mice established neural mechanisms for how encoding mechanisms might handle working memory and predictive processes without "overwriting" recent sensory events in instances where predictive mechanisms are triggered by oddballs within a sequence.11 However, it remains unclear whether mnemonic and predictive information can be decoded from cortical activity simultaneously during passive, implicit sequence processing, even in anesthetized models. Here, we recorded neural activity elicited by repeated stimulus sequences using electrocorticography (ECoG) in the auditory cortex of anesthetized rats, where events within the sequence (referred to henceforth as "vowels," for simplicity) were occasionally replaced with a broadband noise burst or omitted entirely. We show that both stimulus history and predicted stimuli can be decoded from neural responses to broadband impulses, at overlapping latencies but based on independent and uncorrelated data features. We also demonstrate that predictive representations are dynamically updated over the course of stimulation.
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Affiliation(s)
- Drew Cappotto
- Department of Neuroscience, City University of Hong Kong, 31 To Yuen Street, Kowloon Tong, Hong Kong.
| | - HiJee Kang
- Department of Neuroscience, City University of Hong Kong, 31 To Yuen Street, Kowloon Tong, Hong Kong
| | - Kongyan Li
- Department of Neuroscience, City University of Hong Kong, 31 To Yuen Street, Kowloon Tong, Hong Kong
| | - Lucia Melloni
- Neural Circuits, Consciousness and Cognition Research Group, Max Planck Institute for Empirical Aesthetics, Grüneburgweg 14, 60322 Frankfurt am Main, Germany
| | - Jan Schnupp
- Department of Neuroscience, City University of Hong Kong, 31 To Yuen Street, Kowloon Tong, Hong Kong
| | - Ryszard Auksztulewicz
- Department of Neuroscience, City University of Hong Kong, 31 To Yuen Street, Kowloon Tong, Hong Kong; Neural Circuits, Consciousness and Cognition Research Group, Max Planck Institute for Empirical Aesthetics, Grüneburgweg 14, 60322 Frankfurt am Main, Germany; European Neuroscience Institute Göttingen: A Joint Initiative of the University Medical Center Göttingen and the Max Planck Society, Grisebachstraße 5, 37077 Göttingen, Germany
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13
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Lesicko AMH, Angeloni CF, Blackwell JM, De Biasi M, Geffen MN. Cortico-fugal regulation of predictive coding. eLife 2022; 11:73289. [PMID: 35290181 PMCID: PMC8983050 DOI: 10.7554/elife.73289] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 03/12/2022] [Indexed: 11/13/2022] Open
Abstract
Sensory systems must account for both contextual factors and prior experience to adaptively engage with the dynamic external environment. In the central auditory system, neurons modulate their responses to sounds based on statistical context. These response modulations can be understood through a hierarchical predictive coding lens: responses to repeated stimuli are progressively decreased, in a process known as repetition suppression, whereas unexpected stimuli produce a prediction error signal. Prediction error incrementally increases along the auditory hierarchy from the inferior colliculus (IC) to the auditory cortex (AC), suggesting that these regions may engage in hierarchical predictive coding. A potential substrate for top-down predictive cues is the massive set of descending projections from the auditory cortex to subcortical structures, although the role of this system in predictive processing has never been directly assessed. We tested the effect of optogenetic inactivation of the auditory cortico-collicular feedback in awake mice on responses of IC neurons to stimuli designed to test prediction error and repetition suppression. Inactivation of the cortico-collicular pathway led to a decrease in prediction error in IC. Repetition suppression was unaffected by cortico-collicular inactivation, suggesting that this metric may reflect fatigue of bottom-up sensory inputs rather than predictive processing. We also discovered populations of IC units that exhibit repetition enhancement, a sequential increase in firing with stimulus repetition. Cortico-collicular inactivation led to a decrease in repetition enhancement in the central nucleus of IC, suggesting that it is a top-down phenomenon. Negative prediction error, a stronger response to a tone in a predictable rather than unpredictable sequence, was suppressed in shell IC units during cortico-collicular inactivation. These changes in predictive coding metrics arose from bidirectional modulations in the response to the standard and deviant contexts, such that units in IC responded more similarly to each context in the absence of cortical input. We also investigated how these metrics compare between the anesthetized and awake states by recording from the same units under both conditions. We found that metrics of predictive coding and deviance detection differ depending on the anesthetic state of the animal, with negative prediction error emerging in the central IC and repetition enhancement and prediction error being more prevalent in the absence of anesthesia. Overall, our results demonstrate that the auditory cortex provides cues about the statistical context of sound to subcortical brain regions via direct feedback, regulating processing of both prediction and repetition.
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Affiliation(s)
- Alexandria M H Lesicko
- Department of Otorhinolaryngology, University of Pennsylvania, Philadelphia, United States
| | | | - Jennifer M Blackwell
- Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, United States
| | - Mariella De Biasi
- Department of Psychiatry, University of Pennsylvania, Philadelphia, United States
| | - Maria N Geffen
- Department of Otorhinolaryngology, University of Pennsylvania, Philadelphia, United States
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14
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Tivadar RI, Knight RT, Tzovara A. Automatic Sensory Predictions: A Review of Predictive Mechanisms in the Brain and Their Link to Conscious Processing. Front Hum Neurosci 2021; 15:702520. [PMID: 34489663 PMCID: PMC8416526 DOI: 10.3389/fnhum.2021.702520] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 07/12/2021] [Indexed: 01/22/2023] Open
Abstract
The human brain has the astonishing capacity of integrating streams of sensory information from the environment and forming predictions about future events in an automatic way. Despite being initially developed for visual processing, the bulk of predictive coding research has subsequently focused on auditory processing, with the famous mismatch negativity signal as possibly the most studied signature of a surprise or prediction error (PE) signal. Auditory PEs are present during various consciousness states. Intriguingly, their presence and characteristics have been linked with residual levels of consciousness and return of awareness. In this review we first give an overview of the neural substrates of predictive processes in the auditory modality and their relation to consciousness. Then, we focus on different states of consciousness - wakefulness, sleep, anesthesia, coma, meditation, and hypnosis - and on what mysteries predictive processing has been able to disclose about brain functioning in such states. We review studies investigating how the neural signatures of auditory predictions are modulated by states of reduced or lacking consciousness. As a future outlook, we propose the combination of electrophysiological and computational techniques that will allow investigation of which facets of sensory predictive processes are maintained when consciousness fades away.
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Affiliation(s)
| | - Robert T. Knight
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, United States
- Department of Psychology, University of California, Berkeley, Berkeley, CA, United States
| | - Athina Tzovara
- Institute of Computer Science, University of Bern, Bern, Switzerland
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, United States
- Sleep-Wake Epilepsy Center | NeuroTec, Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
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15
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Nourski KV, Steinschneider M, Rhone AE, Krause BM, Mueller RN, Kawasaki H, Banks MI. Cortical Responses to Vowel Sequences in Awake and Anesthetized States: A Human Intracranial Electrophysiology Study. Cereb Cortex 2021; 31:5435-5448. [PMID: 34117741 PMCID: PMC8568007 DOI: 10.1093/cercor/bhab168] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 05/22/2021] [Accepted: 05/22/2021] [Indexed: 02/07/2023] Open
Abstract
Elucidating neural signatures of sensory processing across consciousness states is a major focus in neuroscience. Noninvasive human studies using the general anesthetic propofol reveal differential effects on auditory cortical activity, with a greater impact on nonprimary and auditory-related areas than primary auditory cortex. This study used intracranial electroencephalography to examine cortical responses to vowel sequences during induction of general anesthesia with propofol. Subjects were adult neurosurgical patients with intracranial electrodes placed to identify epileptic foci. Data were collected before electrode removal surgery. Stimuli were vowel sequences presented in a target detection task during awake, sedated, and unresponsive states. Averaged evoked potentials (AEPs) and high gamma (70-150 Hz) power were measured in auditory, auditory-related, and prefrontal cortex. In the awake state, AEPs were found throughout studied brain areas; high gamma activity was limited to canonical auditory cortex. Sedation led to a decrease in AEP magnitude. Upon LOC, there was a decrease in the superior temporal gyrus and adjacent auditory-related cortex and a further decrease in AEP magnitude in core auditory cortex, changes in the temporal structure and increased trial-to-trial variability of responses. The findings identify putative biomarkers of LOC and serve as a foundation for future investigations of altered sensory processing.
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Affiliation(s)
- Kirill V Nourski
- Address correspondence to Kirill V. Nourski, MD, PhD, Department of Neurosurgery, The University of Iowa, 200 Hawkins Dr. 1815 JCP, Iowa City, IA 52242, USA.
| | - Mitchell Steinschneider
- Department of Neurology and Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Ariane E Rhone
- Department of Neurosurgery, The University of Iowa, Iowa City, IA 52242, USA
| | - Bryan M Krause
- Department of Anesthesiology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
| | - Rashmi N Mueller
- Department of Neurosurgery, The University of Iowa, Iowa City, IA 52242, USA,Department of Anesthesia, The University of Iowa, Iowa City, IA 52242, USA
| | - Hiroto Kawasaki
- Department of Neurosurgery, The University of Iowa, Iowa City, IA 52242, USA
| | - Matthew I Banks
- Department of Anesthesiology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA,Department of Neuroscience, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
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16
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Henton A, Tzounopoulos T. What's the buzz? The neuroscience and the treatment of tinnitus. Physiol Rev 2021; 101:1609-1632. [PMID: 33769102 DOI: 10.1152/physrev.00029.2020] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Tinnitus is a pervasive public health issue that affects ∼15% of the United States population. Similar estimates have also been shown on a global scale, with similar prevalence found in Europe, Asia, and Africa. The severity of tinnitus is heterogeneous, ranging from mildly bothersome to extremely disruptive. In the United States, ∼10-20% of individuals who experience tinnitus report symptoms that severely reduce their quality of life. Due to the huge personal and societal burden, in the last 20 yr a concerted effort on basic and clinical research has significantly advanced our understanding and treatment of this disorder. Yet, neither full understanding, nor cure exists. We know that tinnitus is the persistent involuntary phantom percept of internally generated nonverbal indistinct noises and tones, which in most cases is initiated by acquired hearing loss and maintained only when this loss is coupled with distinct neuronal changes in auditory and extra-auditory brain networks. Yet, the exact mechanisms and patterns of neural activity that are necessary and sufficient for the perceptual generation and maintenance of tinnitus remain incompletely understood. Combinations of animal model and human research will be essential in filling these gaps. Nevertheless, the existing progress in investigating the neurophysiological mechanisms has improved current treatment and highlighted novel targets for drug development and clinical trials. The aim of this review is to thoroughly discuss the current state of human and animal tinnitus research, outline current challenges, and highlight new and exciting research opportunities.
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Affiliation(s)
- A Henton
- Pittsburgh Hearing Research Center and Department of Otolaryngology, University of Pittsburgh, Pittsburgh, Pennsylvania.,Center for Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - T Tzounopoulos
- Pittsburgh Hearing Research Center and Department of Otolaryngology, University of Pittsburgh, Pittsburgh, Pennsylvania.,Center for Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania
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17
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Kang H, Auksztulewicz R, An H, Abi Chacra N, Sutter ML, Schnupp JWH. Neural Correlates of Auditory Pattern Learning in the Auditory Cortex. Front Neurosci 2021; 15:610978. [PMID: 33790730 PMCID: PMC8005649 DOI: 10.3389/fnins.2021.610978] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 02/23/2021] [Indexed: 11/13/2022] Open
Abstract
Learning of new auditory stimuli often requires repetitive exposure to the stimulus. Fast and implicit learning of sounds presented at random times enables efficient auditory perception. However, it is unclear how such sensory encoding is processed on a neural level. We investigated neural responses that are developed from a passive, repetitive exposure to a specific sound in the auditory cortex of anesthetized rats, using electrocorticography. We presented a series of random sequences that are generated afresh each time, except for a specific reference sequence that remains constant and re-appears at random times across trials. We compared induced activity amplitudes between reference and fresh sequences. Neural responses from both primary and non-primary auditory cortical regions showed significantly decreased induced activity amplitudes for reference sequences compared to fresh sequences, especially in the beta band. This is the first study showing that neural correlates of auditory pattern learning can be evoked even in anesthetized, passive listening animal models.
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Affiliation(s)
- Hijee Kang
- Department of Neuroscience, City University of Hong Kong, Kowloon, Hong Kong
| | - Ryszard Auksztulewicz
- Department of Neuroscience, City University of Hong Kong, Kowloon, Hong Kong.,Neuroscience Department, Max Planck Institute for Empirical Aesthetics, Frankfurt, Germany
| | - Hyunjung An
- Department of Neuroscience, City University of Hong Kong, Kowloon, Hong Kong
| | - Nicolas Abi Chacra
- Department of Neuroscience, City University of Hong Kong, Kowloon, Hong Kong
| | - Mitchell L Sutter
- Center for Neuroscience and Section of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA, United States
| | - Jan W H Schnupp
- Department of Neuroscience, City University of Hong Kong, Kowloon, Hong Kong
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18
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Gruenbaum BF. Comparison of anaesthetic- and seizure-induced states of unconsciousness: a narrative review. Br J Anaesth 2021; 126:219-229. [PMID: 32951841 PMCID: PMC7844374 DOI: 10.1016/j.bja.2020.07.056] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 06/23/2020] [Accepted: 07/20/2020] [Indexed: 10/23/2022] Open
Abstract
In order to understand general anaesthesia and certain seizures, a fundamental understanding of the neurobiology of unconsciousness is needed. This review article explores similarities in neuronal and network changes during general anaesthesia and seizure-induced unconsciousness. Both seizures and anaesthetics cause disruption in similar anatomical structures that presumably lead to impaired consciousness. Despite differences in behaviour and mechanisms, both of these conditions are associated with disruption of the functionality of subcortical structures that mediate neuronal activity in the frontoparietal cortex. These areas are all likely to be involved in maintaining normal consciousness. An assessment of the similarities in the brain network disruptions with certain seizures and general anaesthesia might provide fresh insights into the mechanisms of the alterations of consciousness seen in these particular unconscious states, allowing for innovative therapies for seizures and the development of anaesthetic approaches targeting specific networks.
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19
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Effect of Stimulus-Dependent Spike Timing on Population Coding of Sound Location in the Owl's Auditory Midbrain. eNeuro 2020; 7:ENEURO.0244-19.2020. [PMID: 32188709 PMCID: PMC7189487 DOI: 10.1523/eneuro.0244-19.2020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 02/07/2020] [Accepted: 02/18/2020] [Indexed: 11/21/2022] Open
Abstract
In the auditory system, the spectrotemporal structure of acoustic signals determines the temporal pattern of spikes. Here, we investigated this effect in neurons of the barn owl's auditory midbrain (Tyto furcata) that are selective for auditory space and whether it can influence the coding of sound direction. We found that in the nucleus where neurons first become selective to combinations of sound localization cues, reproducibility of spike trains across repeated trials of identical sounds, a metric of across-trial temporal fidelity of spiking patterns evoked by a stimulus, was maximal at the sound direction that elicited the highest firing rate. We then tested the hypothesis that this stimulus-dependent patterning resulted in rate co-modulation of cells with similar frequency and spatial selectivity, driving stimulus-dependent synchrony of population responses. Tetrodes were used to simultaneously record multiple nearby units in the optic tectum (OT), where auditory space is topographically represented. While spiking of neurons in OT showed lower reproducibility across trials compared with upstream nuclei, spike-time synchrony between nearby OT neurons was highest for sounds at their preferred direction. A model of the midbrain circuit explained the relationship between stimulus-dependent reproducibility and synchrony, and demonstrated that this effect can improve the decoding of sound location from the OT output. Thus, stimulus-dependent spiking patterns in the auditory midbrain can have an effect on spatial coding. This study reports a functional connection between spike patterning elicited by spectrotemporal features of a sound and the coding of its location.
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20
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Macias S, Bakshi K, Smotherman M. Laminar Organization of FM Direction Selectivity in the Primary Auditory Cortex of the Free-Tailed Bat. Front Neural Circuits 2019; 13:76. [PMID: 31827425 PMCID: PMC6890848 DOI: 10.3389/fncir.2019.00076] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 11/13/2019] [Indexed: 01/18/2023] Open
Abstract
We studied the columnar and layer-specific response properties of neurons in the primary auditory cortex (A1) of six (four females, two males) anesthetized free-tailed bats, Tadarida brasiliensis, in response to pure tones and down and upward frequency modulated (FM; 50 kHz bandwidth) sweeps. In addition, we calculated current source density (CSD) to test whether lateral intracortical projections facilitate neuronal activation in response to FM echoes containing spectrally distant frequencies from the excitatory frequency response area (FRA). Auditory responses to a set of stimuli changing in frequency and level were recorded along 64 penetrations in the left A1 of six free-tailed bats. FRA shapes were consistent across the cortical depth within a column and there were no obvious differences in tuning properties. Generally, response latencies were shorter (<10 ms) for cortical depths between 500 and 600 μm, which might correspond to thalamocortical input layers IIIb-IV. Most units showed a stronger response to downward FM sweeps, and direction selectivity did not vary across cortical depth. CSD profiles calculated in response to the CF showed a current sink located at depths between 500 and 600 μm. Frequencies lower than the frequency range eliciting a spike response failed to evoke any visible current sink. Frequencies higher than the frequency range producing a spike response evoked layer IV sinks at longer latencies that increased with spectral distance. These data support the hypothesis that a progressive downward relay of spectral information spreads along the tonotopic axis of A1 via lateral connections, contributing to the neural processing of FM down sweeps used in biosonar.
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Affiliation(s)
- Silvio Macias
- Department of Biology, Texas A&M University, College Station, TX, United States
| | - Kushal Bakshi
- Department of Biology, Texas A&M University, College Station, TX, United States
| | - Michael Smotherman
- Department of Biology, Texas A&M University, College Station, TX, United States
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21
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Movement and VIP Interneuron Activation Differentially Modulate Encoding in Mouse Auditory Cortex. eNeuro 2019; 6:ENEURO.0164-19.2019. [PMID: 31481397 PMCID: PMC6751373 DOI: 10.1523/eneuro.0164-19.2019] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 08/02/2019] [Accepted: 08/14/2019] [Indexed: 11/22/2022] Open
Abstract
Information processing in sensory cortex is highly sensitive to nonsensory variables such as anesthetic state, arousal, and task engagement. Recent work in mouse visual cortex suggests that evoked firing rates, stimulus–response mutual information, and encoding efficiency increase when animals are engaged in movement. A disinhibitory circuit appears central to this change: inhibitory neurons expressing vasoactive intestinal peptide (VIP) are activated during movement and disinhibit pyramidal cells by suppressing other inhibitory interneurons. Paradoxically, although movement activates a similar disinhibitory circuit in auditory cortex (ACtx), most ACtx studies report reduced spiking during movement. It is unclear whether the resulting changes in spike rates result in corresponding changes in stimulus–response mutual information. We examined ACtx responses evoked by tone cloud stimuli, in awake mice of both sexes, during spontaneous movement and still conditions. VIP+ cells were optogenetically activated on half of trials, permitting independent analysis of the consequences of movement and VIP activation, as well as their intersection. Movement decreased stimulus-related spike rates as well as mutual information and encoding efficiency. VIP interneuron activation tended to increase stimulus-evoked spike rates but not stimulus–response mutual information, thus reducing encoding efficiency. The intersection of movement and VIP activation was largely consistent with a linear combination of these main effects: VIP activation recovered movement-induced reduction in spike rates, but not information transfer.
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22
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Murphy C, Krause B, Banks M. Selective effects of isoflurane on cortico-cortical feedback afferent responses in murine non-primary neocortex. Br J Anaesth 2019; 123:488-496. [PMID: 31383363 DOI: 10.1016/j.bja.2019.06.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 05/28/2019] [Accepted: 06/22/2019] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND General anaesthetics affect loss of consciousness by disrupting information-passing and integration within thalamo-cortical (TC) networks. Feedback cortical connections that carry internally generated signals such as expectation and attention appear more sensitive to anaesthesia than feedforward signals. However, direct evidence for this effect in non-primary cortex is lacking. In addition, direct comparisons between TC core and matrix, and between cortico-cortical (CC) feedforward and feedback responses have not been reported. METHODS We investigated the disruption of synaptic responses by isoflurane of four distinct afferent pathways to non-primary neocortex. We independently activated TC core and matrix and reciprocal CC (feedforward and feedback) pathways using optogenetic techniques, and compared the relative sensitivity of synaptic responses to isoflurane. RESULTS Under control conditions, activation of axon terminals of all pathways evoked postsynaptic currents (recorded extracellularly) and postsynaptic potentials in pyramidal neurones. CC feedback responses were substantially more sensitive to isoflurane (0 to 0.53 mM) compared with TC core, TC matrix, or CC feedforward pathways. CONCLUSION Differential sensitivity of CC feedback synaptic responses to isoflurane in a clinically relevant range suggests a role for disruption of these afferents in the hypnotic effects of anaesthetic agents.
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Affiliation(s)
- Caitlin Murphy
- Physiology Graduate Training Program, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA; Department of Anesthesiology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
| | - Bryan Krause
- Department of Anesthesiology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Matthew Banks
- Department of Anesthesiology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
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23
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Sharma HS, Muresanu DF, Nozari A, Castellani RJ, Dey PK, Wiklund L, Sharma A. Anesthetics influence concussive head injury induced blood-brain barrier breakdown, brain edema formation, cerebral blood flow, serotonin levels, brain pathology and functional outcome. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2019; 146:45-81. [PMID: 31349932 DOI: 10.1016/bs.irn.2019.06.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Several lines of evidences show that anesthetics influence neurotoxicity and neuroprotection. The possibility that different anesthetic agents potentially influence the pathophysiological and functional outcome following neurotrauma was examined in a rat model of concussive head injury (CHI). The CHI was produced by an impact of 0.224N on the right parietal bone by dropping a weight of 114.6g from a 20cm height under different anesthetic agents, e.g., inhaled ether anesthesia or intraperitoneally administered ketamine, pentobarbital, equithesin or urethane anesthesia. Five hour CHI resulted in profound volume swelling and brain edema formation in both hemispheres showing disruption of the blood-brain barrier (BBB) to Evans blue and radioiodine. A marked decrease in the cortical CBF and a profound increase in plasma or brain serotonin levels were seen at this time. Neuronal damages were present in several parts of the brain. These pathological changes were most marked in CHI under ether anesthesia followed by ketamine (35mg/kg, i.p.), pentobarbital (50mg/kg, i.p.), equithesin (3mL/kg, i.p.) and urethane (1g/kg, i.p.). The functional outcome on Rota Rod performances or grid walking tests was also most adversely affected after CHI under ether anesthesia followed by pentobarbital, equithesin and ketamine. Interestingly, the plasma and brain serotonin levels strongly correlated with the development of brain edema in head injured animals in relation to different anesthetic agents used. These observations suggest that anesthetic agents are detrimental to functional and pathological outcomes in CHI probably through influencing the circulating plasma and brain serotonin levels, not reported earlier. Whether anesthetics could also affect the efficacy of different neuroprotective agents in CNS injuries is a new subject that is currently being examined in our laboratory.
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Affiliation(s)
- Hari Shanker Sharma
- International Experimental Central Nervous System Injury & Repair (IECNSIR), Department of Surgical Sciences, Anesthesiology & Intensive Care Medicine, Uppsala University Hospital, Uppsala University, Uppsala, Sweden.
| | - Dafin Fior Muresanu
- Department of Clinical Neurosciences, University of Medicine & Pharmacy, Cluj-Napoca, Romania; "RoNeuro" Institute for Neurological Research and Diagnostic, Cluj-Napoca, Romania
| | - Ala Nozari
- Anesthesia and Critical Care, Massachusetts General Hospital, Boston, MA, United States
| | - Rudy J Castellani
- Department of Pathology, University of Maryland, Baltimore, MD, United States
| | - Prasanta Kumar Dey
- Neurophysiology Research Unit, Department of Physiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Lars Wiklund
- International Experimental Central Nervous System Injury & Repair (IECNSIR), Department of Surgical Sciences, Anesthesiology & Intensive Care Medicine, Uppsala University Hospital, Uppsala University, Uppsala, Sweden
| | - Aruna Sharma
- International Experimental Central Nervous System Injury & Repair (IECNSIR), Department of Surgical Sciences, Anesthesiology & Intensive Care Medicine, Uppsala University Hospital, Uppsala University, Uppsala, Sweden
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Voss LJ, García PS, Hentschke H, Banks MI. Understanding the Effects of General Anesthetics on Cortical Network Activity Using Ex Vivo Preparations. Anesthesiology 2019; 130:1049-1063. [PMID: 30694851 PMCID: PMC6520142 DOI: 10.1097/aln.0000000000002554] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
General anesthetics have been used to ablate consciousness during surgery for more than 150 yr. Despite significant advances in our understanding of their molecular-level pharmacologic effects, comparatively little is known about how anesthetics alter brain dynamics to cause unconsciousness. Consequently, while anesthesia practice is now routine and safe, there are many vagaries that remain unexplained. In this paper, the authors review the evidence that cortical network activity is particularly sensitive to general anesthetics, and suggest that disruption to communication in, and/or among, cortical brain regions is a common mechanism of anesthesia that ultimately produces loss of consciousness. The authors review data from acute brain slices and organotypic cultures showing that anesthetics with differing molecular mechanisms of action share in common the ability to impair neurophysiologic communication. While many questions remain, together, ex vivo and in vivo investigations suggest that a unified understanding of both clinical anesthesia and the neural basis of consciousness is attainable.
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Affiliation(s)
- Logan J Voss
- From the Department of Anaesthesia, Waikato District Health Board, Hamilton, New Zealand (L.J.V.) the Department of Anesthesiology, Emory University School of Medicine, Atlanta, Georgia (P.S.G) Anesthesiology and Research Divisions, Atlanta Veterans Administration Medical Center, Atlanta, Georgia (P.S.G.) the Experimental Anesthesiology Section, Department of Anesthesiology, University Hospital of Tübingen, Tübingen, Germany (H.H.) rthe Department of Anesthesiology, University of Wisconsin, Madison, Wisconsin (M.I.B.)
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25
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Kim YR, Kim CE, Yoon H, Kim SK, Kim SJ. S1 Employs Feature-Dependent Differential Selectivity of Single Cells and Distributed Patterns of Populations to Encode Mechanosensations. Front Cell Neurosci 2019; 13:132. [PMID: 31024261 PMCID: PMC6460949 DOI: 10.3389/fncel.2019.00132] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 03/18/2019] [Indexed: 11/23/2022] Open
Abstract
The primary somatosensory (S1) cortex plays an important role in the perception and discrimination of touch and pain mechanosensations. Conventionally, neurons in the somatosensory system including S1 cortex have been classified into low/high threshold (HT; non-nociceptive/nociceptive) or wide dynamic range (WDR; convergent) neurons by their electrophysiological responses to innocuous brush-stroke and noxious forceps-pinch stimuli. Besides this “noxiousness” (innocuous/noxious) feature, each stimulus also includes other stimulus features: “texture” (brush hairs/forceps-steel arm), “dynamics” (dynamic stroke/static press) and “intensity” (weak/strong). However, it remains unknown how S1 neurons inclusively process such diverse features of brushing and pinch at the single-cell and population levels. Using in vivo two-photon Ca2+ imaging in the layer 2/3 neurons of the mouse S1 cortex, we identified clearly separated response patterns of the S1 neural population with distinct tuning properties of individual cells to texture, dynamics and noxiousness features of cutaneous mechanical stimuli. Among cells other than broadly tuned neurons, the majority of the cells showed a highly selective response to the difference in texture, but low selectivity to the difference in dynamics or noxiousness. Between the two low selectivity features, the difference in dynamics was slightly more specific, yet both could be decoded using the response patterns of neural populations. In addition, more neurons are recruited and stronger Ca2+ responses are evoked as the intensity of forceps-pinch is gradually increased. Our results suggest that S1 neurons encode various features of mechanosensations with feature-dependent differential selectivity of single cells and distributed response patterns of populations. Moreover, we raise a caution about describing neurons by a single stimulus feature ignoring other aspects of the sensory stimuli.
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Affiliation(s)
- Yoo Rim Kim
- Department of Physiology, Seoul National University College of Medicine, Seoul, South Korea.,Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, South Korea
| | - Chang-Eop Kim
- Department of Physiology, Seoul National University College of Medicine, Seoul, South Korea.,Department of Physiology, College of Korean Medicine, Gachon University, Gyeonggi-do, South Korea
| | - Heera Yoon
- Department of Science in Korean Medicine, Graduate School, Kyung Hee University, Seoul, South Korea
| | - Sun Kwang Kim
- Department of Science in Korean Medicine, Graduate School, Kyung Hee University, Seoul, South Korea.,Department of Physiology, College of Korean Medicine, Kyung Hee University, Seoul, South Korea
| | - Sang Jeong Kim
- Department of Physiology, Seoul National University College of Medicine, Seoul, South Korea.,Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, South Korea.,Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, South Korea
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26
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Hörpel SG, Firzlaff U. Processing of fast amplitude modulations in bat auditory cortex matches communication call-specific sound features. J Neurophysiol 2019; 121:1501-1512. [PMID: 30785811 DOI: 10.1152/jn.00748.2018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Bats use a large repertoire of calls for social communication. In the bat Phyllostomus discolor, social communication calls are often characterized by sinusoidal amplitude and frequency modulations with modulation frequencies in the range of 100-130 Hz. However, peaks in mammalian auditory cortical modulation transfer functions are typically limited to modulation frequencies below 100 Hz. We investigated the coding of sinusoidally amplitude modulated sounds in auditory cortical neurons in P. discolor by constructing rate and temporal modulation transfer functions. Neuronal responses to playbacks of various communication calls were additionally recorded and compared with the neurons' responses to sinusoidally amplitude-modulated sounds. Cortical neurons in the posterior dorsal field of the auditory cortex were tuned to unusually high modulation frequencies: rate modulation transfer functions often peaked around 130 Hz (median: 87 Hz), and the median of the highest modulation frequency that evoked significant phase-locking was also 130 Hz. Both values are much higher than reported from the auditory cortex of other mammals, with more than 51% of the units preferring modulation frequencies exceeding 100 Hz. Conspicuously, the fast modulations preferred by the neurons match the fast amplitude and frequency modulations of prosocial, and mostly of aggressive, communication calls in P. discolor. We suggest that the preference for fast amplitude modulations in the P. discolor dorsal auditory cortex serves to reliably encode the fast modulations seen in their communication calls. NEW & NOTEWORTHY Neural processing of temporal sound features is crucial for the analysis of communication calls. In bats, these calls are often characterized by fast temporal envelope modulations. Because auditory cortex neurons typically encode only low modulation frequencies, it is unclear how species-specific vocalizations are cortically processed. We show that auditory cortex neurons in the bat Phyllostomus discolor encode fast temporal envelope modulations. This property improves response specificity to communication calls and thus might support species-specific communication.
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Affiliation(s)
- Stephen Gareth Hörpel
- Chair of Zoology, Department of Animal Sciences, Technical University of Munich , Freising , Germany
| | - Uwe Firzlaff
- Chair of Zoology, Department of Animal Sciences, Technical University of Munich , Freising , Germany
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27
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Remington ED, Wang X. Neural Representations of the Full Spatial Field in Auditory Cortex of Awake Marmoset (Callithrix jacchus). Cereb Cortex 2019; 29:1199-1216. [PMID: 29420692 PMCID: PMC6373678 DOI: 10.1093/cercor/bhy025] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 01/13/2018] [Indexed: 11/14/2022] Open
Abstract
Unlike visual signals, sound can reach the ears from any direction, and the ability to localize sounds from all directions is essential for survival in a natural environment. Previous studies have largely focused on the space in front of a subject that is also covered by vision and were often limited to measuring spatial tuning along the horizontal (azimuth) plane. As a result, we know relatively little about how the auditory cortex responds to sounds coming from spatial locations outside the frontal space where visual information is unavailable. By mapping single-neuron responses to the full spatial field in awake marmoset (Callithrix jacchus), an arboreal animal for which spatial processing is vital in its natural habitat, we show that spatial receptive fields in several auditory areas cover all spatial locations. Several complementary measures of spatial tuning showed that neurons were tuned to both frontal space and rear space (outside the coverage of vision), as well as the space above and below the horizontal plane. Together, these findings provide valuable new insights into the representation of all spatial locations by primate auditory cortex.
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Affiliation(s)
- Evan D Remington
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Xiaoqin Wang
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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Hentschke H, Raz A, Krause BM, Murphy CA, Banks MI. Disruption of cortical network activity by the general anaesthetic isoflurane. Br J Anaesth 2019; 119:685-696. [PMID: 29121295 DOI: 10.1093/bja/aex199] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/02/2017] [Indexed: 02/03/2023] Open
Abstract
Background Actions of general anaesthetics on activity in the cortico-thalamic network likely contribute to loss of consciousness and disconnection from the environment. Previously, we showed that the general anaesthetic isoflurane preferentially suppresses cortically evoked synaptic responses compared with thalamically evoked synaptic responses, but how this differential sensitivity translates into changes in network activity is unclear. Methods We investigated isoflurane disruption of spontaneous and stimulus-induced cortical network activity using multichannel recordings in murine auditory thalamo-cortical brain slices. Results Under control conditions, afferent stimulation elicited short latency, presumably monosynaptically driven, spiking responses, as well as long latency network bursts that propagated horizontally through the cortex. Isoflurane (0.05-0.6 mM) suppressed spiking activity overall, but had a far greater effect on network bursts than on early spiking responses. At isoflurane concentrations >0.3 mM, network bursts were almost entirely blocked, even with increased stimulation intensity and in response to paired (thalamo-cortical + cortical layer 1) stimulation, while early spiking responses were <50% blocked. Isoflurane increased the threshold for eliciting bursts, decreased their propagation speed and prevented layer 1 afferents from facilitating burst induction by thalamo-cortical afferents. Conclusions Disruption of horizontal activity spread and of layer 1 facilitation of thalamo-cortical responses likely contribute to the mechanism by which suppression of cortical feedback connections disrupts sensory awareness under anaesthesia.
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Affiliation(s)
- H Hentschke
- Department of Anesthesiology, Experimental Anesthesiology Section, University Hospital of Tübingen, Tübingen, Germany
| | - A Raz
- Department of Anesthesiology, University of Wisconsin, Madison, WI, USA.,Department of Anesthesiology, Rambam Health Care Campus, Haifa, Israel
| | - B M Krause
- Department of Anesthesiology, University of Wisconsin, Madison, WI, USA
| | - C A Murphy
- Department of Anesthesiology, University of Wisconsin, Madison, WI, USA.,Physiology Graduate Training Program, University of Wisconsin, Madison, WI, USA
| | - M I Banks
- Department of Anesthesiology, University of Wisconsin, Madison, WI, USA
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Banks MI, Moran NS, Krause BM, Grady SM, Uhlrich DJ, Manning KA. Altered stimulus representation in rat auditory cortex is not causal for loss of consciousness under general anaesthesia. Br J Anaesth 2018; 121:605-615. [PMID: 30115259 DOI: 10.1016/j.bja.2018.05.054] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 05/13/2018] [Accepted: 05/21/2018] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Current concepts suggest that impaired representation of information in cortical networks contributes to loss of consciousness under anaesthesia. We tested this idea in rat auditory cortex using information theory analysis of multiunit responses recorded under three anaesthetic agents with different molecular targets: isoflurane, propofol, and dexmedetomidine. We reasoned that if changes in the representation of sensory stimuli are causal for loss of consciousness, they should occur regardless of the specific anaesthetic agent. METHODS Spiking responses were recorded with chronically implanted microwire arrays in response to acoustic stimuli incorporating varied temporal and spectral dynamics. Experiments consisted of four drug conditions: awake (pre-drug), sedation (i.e. intact righting reflex), loss of consciousness (a dose just sufficient to cause loss of righting reflex), and recovery. Measures of firing rate, spike timing, and mutual information were analysed as a function of drug condition. RESULTS All three drugs decreased spontaneous and evoked spiking activity and modulated spike timing. However, changes in mutual information were inconsistent with altered stimulus representation being causal for loss of consciousness. First, direction of change in mutual information was agent-specific, increasing under dexmedetomidine and decreasing under isoflurane and propofol. Second, mutual information did not decrease at the transition between sedation and LOC for any agent. Changes in mutual information under anaesthesia correlated strongly with changes in precision and reliability of spike timing, consistent with the importance of temporal stimulus features in driving auditory cortical activity. CONCLUSIONS The primary sensory cortex is not the locus for changes in representation of information causal for loss of consciousness under anaesthesia.
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Affiliation(s)
- M I Banks
- Department of Anesthesiology, University of Wisconsin, Madison, WI, USA.
| | - N S Moran
- Neuroscience Training Program, University of Wisconsin, Madison, WI, USA
| | - B M Krause
- Department of Anesthesiology, University of Wisconsin, Madison, WI, USA
| | - S M Grady
- Department of Anesthesiology, University of Wisconsin, Madison, WI, USA
| | - D J Uhlrich
- Department of Neuroscience, University of Wisconsin, Madison, WI, USA
| | - K A Manning
- Department of Neuroscience, University of Wisconsin, Madison, WI, USA
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30
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Aralla R, Ashida G, Köppl C. Binaural responses in the auditory midbrain of chicken (Gallus gallus). Eur J Neurosci 2018; 51:1290-1304. [PMID: 29582488 DOI: 10.1111/ejn.13891] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 02/20/2018] [Accepted: 02/26/2018] [Indexed: 11/29/2022]
Abstract
The auditory midbrain is the location in which neurons represent binaural acoustic information necessary for sound localization. The external nucleus of the midbrain inferior colliculus (IC) of the barn owl is a classic example of an auditory space map, but it is unknown to what extent the principles underlying its formation generalize to other, less specialized animals. We characterized the spiking responses of 139 auditory neurons in the IC of the chicken (Gallus gallus) in vivo, focusing on their sensitivities to the binaural localization cues of interaural time (ITD) and level (ILD) differences. Most units were frequency-selective, with best frequencies distributed unevenly into low-frequency and high-frequency (> 2 kHz) clusters. Many units showed sensitivity to either ITD (65%) or ILD (66%) and nearly half to both (47%). ITD selectivity was disproportionately more common among low-frequency units, while ILD-only selective units were predominantly tuned to high frequencies. ILD sensitivities were diverse, and we thus developed a decision tree defining five types. One rare type with a bell-like ILD tuning was also selective for ITD but typically not frequency-selective, and thus matched the characteristics of neurons in the auditory space map of the barn owl. Our results suggest that generalist birds such as the chicken show a prominent representation of ITD and ILD cues in the IC, providing complementary information for sound localization, according to the duplex theory. A broadband response type narrowly selective for both ITD and ILD may form the basis for a representation of auditory space.
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Affiliation(s)
- Roberta Aralla
- Department of Neuroscience, School of Medicine and Health Sciences, Research Center for Neurosensory Sciences and Cluster of Excellence 'Hearing4all', Carl von Ossietzky University, Carl von Ossietzky Strasse 9-11, 26129, Oldenburg, Germany
| | - Go Ashida
- Department of Neuroscience, School of Medicine and Health Sciences, Research Center for Neurosensory Sciences and Cluster of Excellence 'Hearing4all', Carl von Ossietzky University, Carl von Ossietzky Strasse 9-11, 26129, Oldenburg, Germany
| | - Christine Köppl
- Department of Neuroscience, School of Medicine and Health Sciences, Research Center for Neurosensory Sciences and Cluster of Excellence 'Hearing4all', Carl von Ossietzky University, Carl von Ossietzky Strasse 9-11, 26129, Oldenburg, Germany
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31
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David SV. Incorporating behavioral and sensory context into spectro-temporal models of auditory encoding. Hear Res 2018; 360:107-123. [PMID: 29331232 PMCID: PMC6292525 DOI: 10.1016/j.heares.2017.12.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 12/18/2017] [Accepted: 12/26/2017] [Indexed: 01/11/2023]
Abstract
For several decades, auditory neuroscientists have used spectro-temporal encoding models to understand how neurons in the auditory system represent sound. Derived from early applications of systems identification tools to the auditory periphery, the spectro-temporal receptive field (STRF) and more sophisticated variants have emerged as an efficient means of characterizing representation throughout the auditory system. Most of these encoding models describe neurons as static sensory filters. However, auditory neural coding is not static. Sensory context, reflecting the acoustic environment, and behavioral context, reflecting the internal state of the listener, can both influence sound-evoked activity, particularly in central auditory areas. This review explores recent efforts to integrate context into spectro-temporal encoding models. It begins with a brief tutorial on the basics of estimating and interpreting STRFs. Then it describes three recent studies that have characterized contextual effects on STRFs, emerging over a range of timescales, from many minutes to tens of milliseconds. An important theme of this work is not simply that context influences auditory coding, but also that contextual effects span a large continuum of internal states. The added complexity of these context-dependent models introduces new experimental and theoretical challenges that must be addressed in order to be used effectively. Several new methodological advances promise to address these limitations and allow the development of more comprehensive context-dependent models in the future.
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Affiliation(s)
- Stephen V David
- Oregon Hearing Research Center, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd, MC L335A, Portland, OR 97239, United States.
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32
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Van Ruijssevelt L, Chen Y, von Eugen K, Hamaide J, De Groof G, Verhoye M, Güntürkün O, Woolley SC, Van der Linden A. fMRI Reveals a Novel Region for Evaluating Acoustic Information for Mate Choice in a Female Songbird. Curr Biol 2018; 28:711-721.e6. [PMID: 29478859 DOI: 10.1016/j.cub.2018.01.048] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 12/05/2017] [Accepted: 01/17/2018] [Indexed: 01/02/2023]
Abstract
Selection of sexual partners is among the most critical decisions that individuals make and is therefore strongly shaped by evolution. In social species, where communication signals can convey substantial information about the identity, state, or quality of the signaler, accurate interpretation of communication signals for mate choice is crucial. Despite the importance of social information processing, to date, relatively little is known about the neurobiological mechanisms that contribute to sexual decision making and preferences. In this study, we used a combination of whole-brain functional magnetic resonance imaging (fMRI), immediate early gene expression, and behavior tests to identify the circuits that are important for the perception and evaluation of courtship songs in a female songbird, the zebra finch (Taeniopygia guttata). Female zebra finches are sensitive to subtle differences in male song performance and strongly prefer the longer, faster, and more stereotyped courtship songs to non-courtship renditions. Using BOLD fMRI and EGR1 expression assays, we uncovered a novel region involved in auditory perceptual decision making located in a sensory integrative region of the avian central nidopallium outside the traditionally studied auditory forebrain pathways. Changes in activity in this region in response to acoustically similar but categorically divergent stimuli showed stronger parallels to behavioral responses than an auditory sensory region. These data highlight a potential role for the caudocentral nidopallium (NCC) as a novel node in the avian circuitry underlying the evaluation of acoustic signals and their use in mate choice.
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Affiliation(s)
- Lisbeth Van Ruijssevelt
- Bio-Imaging lab, Department of Biomedical Sciences, University of Antwerp, 2610 Antwerpen, Belgium
| | - Yining Chen
- Department of Biology, McGill University, Montreal QC H3A 1B1, Canada
| | - Kaya von Eugen
- AE Biopsychologie, Fakultät für Psychologie, Ruhr-Universität Bochum, 44801 Bochum, Germany
| | - Julie Hamaide
- Bio-Imaging lab, Department of Biomedical Sciences, University of Antwerp, 2610 Antwerpen, Belgium
| | - Geert De Groof
- Bio-Imaging lab, Department of Biomedical Sciences, University of Antwerp, 2610 Antwerpen, Belgium
| | - Marleen Verhoye
- Bio-Imaging lab, Department of Biomedical Sciences, University of Antwerp, 2610 Antwerpen, Belgium
| | - Onur Güntürkün
- AE Biopsychologie, Fakultät für Psychologie, Ruhr-Universität Bochum, 44801 Bochum, Germany
| | - Sarah C Woolley
- Department of Biology, McGill University, Montreal QC H3A 1B1, Canada.
| | - Annemie Van der Linden
- Bio-Imaging lab, Department of Biomedical Sciences, University of Antwerp, 2610 Antwerpen, Belgium.
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Flavoprotein fluorescence imaging-based electrode implantation for subfield-targeted chronic recording in the mouse auditory cortex. J Neurosci Methods 2018; 293:77-85. [PMID: 28851513 DOI: 10.1016/j.jneumeth.2017.08.028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Revised: 08/21/2017] [Accepted: 08/22/2017] [Indexed: 11/21/2022]
Abstract
BACKGROUND Chronic neural recording in freely moving animals is important for understanding neural activities of cortical neurons associated with various behavioral contexts. In small animals such as mice, it has been difficult to implant recording electrodes into exact locations according to stereotactic coordinates, skull geometry, or the shape of blood vessels. The main reason for this difficulty is large individual differences in the exact location of the targeted brain area. NEW METHODS We propose a new electrode implantation procedure that is combined with transcranial flavoprotein fluorescence imaging. We demonstrate the effectiveness of this method in the auditory cortex (AC) of mice. RESULTS Prior to electrode implantation, we executed transcranial flavoprotein fluorescence imaging in anesthetized mice and identified the exact location of AC subfields through the skull in each animal. Next, we surgically implanted a microdrive with a tungsten electrode into exactly the identified location. Finally, we recorded neural activity in freely moving conditions and evaluated the success rate of recording auditory responses. COMPARISON WITH EXISTING METHOD(S) These procedures dramatically improved the success rate of recording auditory responses from 21.1% without imaging to 100.0% with imaging. We also identified large individual differences in positional relationships between sound-driven response areas and the squamosal suture or blood vessels. CONCLUSIONS Combining chronic electrophysiology with transcranial flavoprotein fluorescence imaging before implantation enables the realization of reliable subfield-targeted neural recording from freely moving small animals.
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Esghaei M, Daliri MR, Treue S. Local field potentials are induced by visually evoked spiking activity in macaque cortical area MT. Sci Rep 2017; 7:17110. [PMID: 29215034 PMCID: PMC5719360 DOI: 10.1038/s41598-017-17372-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Accepted: 11/27/2017] [Indexed: 12/14/2022] Open
Abstract
Local field potentials (LFP) have been the focus of many recent studies in systems neuroscience. However, the exact neural basis of these signals remains unclear. To address this question, we determined the relationship between LFP signals and another, much better understood, signature of neural activity: action potentials. Specifically, we focused on the relationship between the amplitude of stimulus-induced LFPs and the magnitude of spiking activity in visual cortex of non-human primates. Our trial-by-trial correlation analyses between these two components of extracellular signals in macaque visual cortex show that the spike rate is coupled to the LFP amplitude with a surprisingly long latency, typically 50 ms. Our analysis shows that the neural spike rate is a significant predictor of the LFP amplitude. This limits the functional interpretation of LFP signals beyond that based on spiking activities.
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Affiliation(s)
- Moein Esghaei
- Cognitive Neurobiology Laboratory, School of Cognitive Sciences, Institute for Research in Fundamental Sciences (IPM), Tehran, Iran. .,Cognitive Neuroscience Laboratory, German Primate Center - Leibniz Institute for Primate Research, Goettingen, Germany.
| | - Mohammad Reza Daliri
- Cognitive Neurobiology Laboratory, School of Cognitive Sciences, Institute for Research in Fundamental Sciences (IPM), Tehran, Iran.,Cognitive Neuroscience Laboratory, German Primate Center - Leibniz Institute for Primate Research, Goettingen, Germany.,Neuroscience and Neuroengineering Research Laboratory, Biomedical Engineering Department, School of Electrical Engineering, Iran University of Science and Technology, Tehran, Iran
| | - Stefan Treue
- Cognitive Neuroscience Laboratory, German Primate Center - Leibniz Institute for Primate Research, Goettingen, Germany.,Faculty of Biology and Psychology, University of Goettingen, Goettingen, Germany.,Bernstein Center for Computational Neuroscience, Goettingen, Germany.,Leibniz-ScienceCampus Primate Cognition, Goettingen, Germany
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Hildebrandt KJ, Sahani M, Linden JF. The Impact of Anesthetic State on Spike-Sorting Success in the Cortex: A Comparison of Ketamine and Urethane Anesthesia. Front Neural Circuits 2017; 11:95. [PMID: 29238293 PMCID: PMC5712555 DOI: 10.3389/fncir.2017.00095] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 11/14/2017] [Indexed: 11/13/2022] Open
Abstract
Spike sorting is an essential first step in most analyses of extracellular in vivo electrophysiological recordings. Here we show that spike-sorting success depends critically on characteristics of coordinated population activity that can differ between anesthetic states. In tetrode recordings from mouse auditory cortex, spike sorting was significantly less successful under ketamine/medetomidine (ket/med) than urethane anesthesia. Surprisingly, this difficulty with sorting under ket/med anesthesia did not appear to result from either greater millisecond-scale burstiness of neural activity or increased coordination of activity among neighboring neurons. Rather, the key factor affecting sorting success appeared to be the amount of coordinated population activity at long time intervals and across large cortical distances. We propose that spike-sorting success is directly dependent on overall coordination of activity, and is most disrupted by large-scale fluctuations in cortical population activity. Reliability of single-unit recording may therefore differ not only between urethane-anesthetized and ket/med-anesthetized states as demonstrated here, but also between synchronized and desynchronized states, asleep and awake states, or inattentive and attentive states in unanesthetized animals.
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Affiliation(s)
- K Jannis Hildebrandt
- Cluster of Excellence Hearing4all, University of Oldenburg, Oldenburg, Germany.,Department of Neuroscience, University of Oldenburg, Oldenburg, Germany
| | - Maneesh Sahani
- Gatsby Computational Neuroscience Unit, University College London, London, United Kingdom
| | - Jennifer F Linden
- Ear Institute, University College London, London, United Kingdom.,Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
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36
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Schaefer MK, Kössl M, Hechavarría JC. Laminar differences in response to simple and spectro-temporally complex sounds in the primary auditory cortex of ketamine-anesthetized gerbils. PLoS One 2017; 12:e0182514. [PMID: 28771568 PMCID: PMC5542772 DOI: 10.1371/journal.pone.0182514] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 07/19/2017] [Indexed: 11/19/2022] Open
Abstract
In mammals, acoustic communication plays an important role during social behaviors. Despite their ethological relevance, the mechanisms by which the auditory cortex represents different communication call properties remain elusive. Recent studies have pointed out that communication-sound encoding could be based on discharge patterns of neuronal populations. Following this idea, we investigated whether the activity of local neuronal networks, such as those occurring within individual cortical columns, is sufficient for distinguishing between sounds that differed in their spectro-temporal properties. To accomplish this aim, we analyzed simple pure-tone and complex communication call elicited multi-unit activity (MUA) as well as local field potentials (LFP), and current source density (CSD) waveforms at the single-layer and columnar level from the primary auditory cortex of anesthetized Mongolian gerbils. Multi-dimensional scaling analysis was used to evaluate the degree of "call-specificity" in the evoked activity. The results showed that whole laminar profiles segregated 1.8-2.6 times better across calls than single-layer activity. Also, laminar LFP and CSD profiles segregated better than MUA profiles. Significant differences between CSD profiles evoked by different sounds were more pronounced at mid and late latencies in the granular and infragranular layers and these differences were based on the absence and/or presence of current sinks and on sink timing. The stimulus-specific activity patterns observed within cortical columns suggests that the joint activity of local cortical populations (as local as single columns) could indeed be important for encoding sounds that differ in their acoustic attributes.
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Affiliation(s)
- Markus K. Schaefer
- Institute for Cell Biology and Neuroscience, AK Neurobiology and Biosensorics, Goethe University, Frankfurt/Main, Germany
- * E-mail:
| | - Manfred Kössl
- Institute for Cell Biology and Neuroscience, AK Neurobiology and Biosensorics, Goethe University, Frankfurt/Main, Germany
| | - Julio C. Hechavarría
- Institute for Cell Biology and Neuroscience, AK Neurobiology and Biosensorics, Goethe University, Frankfurt/Main, Germany
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37
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Phillips EAK, Schreiner CE, Hasenstaub AR. Diverse effects of stimulus history in waking mouse auditory cortex. J Neurophysiol 2017; 118:1376-1393. [PMID: 28566458 DOI: 10.1152/jn.00094.2017] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 05/10/2017] [Accepted: 05/29/2017] [Indexed: 11/22/2022] Open
Abstract
Responses to auditory stimuli are often strongly influenced by recent stimulus history. For example, in a paradigm called forward suppression, brief sounds can suppress the perception of, and the neural responses to, a subsequent sound, with the magnitude of this suppression depending on both the spectral and temporal distances between the sounds. As a step towards understanding the mechanisms that generate these adaptive representations in awake animals, we quantitatively characterize responses to two-tone sequences in the auditory cortex of waking mice. We find that cortical responses in a forward suppression paradigm are more diverse in waking mice than previously appreciated, that these responses vary between cells with different firing characteristics and waveform shapes, but that the variability in these responses is not substantially related to cortical depth or columnar location. Moreover, responses to the first tone in the sequence are often not linearly related to the suppression of the second tone response, suggesting that spike-frequency adaptation of cortical cells is not a large contributor to forward suppression or its variability. Instead, we use a simple multilayered model to show that cell-to-cell differences in the balance of intracortical inhibition and excitation will naturally produce such a diversity of forward interactions. We propose that diverse inhibitory connectivity allows the cortex to encode spectro-temporally fluctuating stimuli in multiple parallel ways.NEW & NOTEWORTHY Behavioral and neural responses to auditory stimuli are profoundly influenced by recent sounds, yet how this occurs is not known. Here, the authors show in the auditory cortex of awake mice that the quality of history-dependent effects is diverse and related to cell type, response latency, firing rates, and receptive field bandwidth. In a cortical model, differences in excitatory-inhibitory balance can produce this diversity, providing the cortex with multiple ways of representing temporally complex information.
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Affiliation(s)
- Elizabeth A K Phillips
- Coleman Memorial Laboratory, University of California, San Francisco, California.,Neuroscience Graduate Program, University of California, San Francisco, California.,Department of Otolaryngology-Head and Neck Surgery, University of California, San Francisco, California.,Center for Integrative Neuroscience, University of California, San Francisco, California; and.,Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, California
| | - Christoph E Schreiner
- Coleman Memorial Laboratory, University of California, San Francisco, California.,Neuroscience Graduate Program, University of California, San Francisco, California.,Department of Otolaryngology-Head and Neck Surgery, University of California, San Francisco, California.,Center for Integrative Neuroscience, University of California, San Francisco, California; and.,Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, California
| | - Andrea R Hasenstaub
- Coleman Memorial Laboratory, University of California, San Francisco, California; .,Neuroscience Graduate Program, University of California, San Francisco, California.,Department of Otolaryngology-Head and Neck Surgery, University of California, San Francisco, California.,Center for Integrative Neuroscience, University of California, San Francisco, California; and.,Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, California
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38
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Anesthesia and brain sensory processing: impact on neuronal responses in a female songbird. Sci Rep 2016; 6:39143. [PMID: 27966648 PMCID: PMC5155427 DOI: 10.1038/srep39143] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 11/10/2016] [Indexed: 11/29/2022] Open
Abstract
Whether anesthesia impacts brain sensory processing is a highly debated and important issue. There is a general agreement that anesthesia tends to diminish neuronal activity, but its potential impact on neuronal “tuning” is still an open question. Here we show, based on electrophysiological recordings in the primary auditory area of a female songbird, that anesthesia induces neuronal responses towards biologically irrelevant sounds and prevents the seasonal neuronal tuning towards functionally relevant species-specific song elements.
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Ramamurthy DL, Recanzone GH. Spectral and spatial tuning of onset and offset response functions in auditory cortical fields A1 and CL of rhesus macaques. J Neurophysiol 2016; 117:966-986. [PMID: 27927783 DOI: 10.1152/jn.00534.2016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 12/06/2016] [Indexed: 11/22/2022] Open
Abstract
The mammalian auditory cortex is necessary for spectral and spatial processing of acoustic stimuli. Most physiological studies of single neurons in the auditory cortex have focused on the onset and sustained portions of evoked responses, but there have been far fewer studies on the relationship between onset and offset responses. In the current study, we compared spectral and spatial tuning of onset and offset responses of neurons in primary auditory cortex (A1) and the caudolateral (CL) belt area of awake macaque monkeys. Several different metrics were used to determine the relationship between onset and offset response profiles in both frequency and space domains. In the frequency domain, a substantial proportion of neurons in A1 and CL displayed highly dissimilar best stimuli for onset- and offset-evoked responses, although even for these neurons, there was usually a large overlap in the range of frequencies that elicited onset, and offset responses and distributions of tuning overlap metrics were mostly unimodal. In the spatial domain, the vast majority of neurons displayed very similar best locations for onset- and offset-evoked responses, along with unimodal distributions of all tuning overlap metrics considered. Finally, for both spectral and spatial tuning, a slightly larger fraction of neurons in A1 displayed nonoverlapping onset and offset response profiles, relative to CL, which supports hierarchical differences in the processing of sounds in the two areas. However, these differences are small compared with differences in proportions of simple cells (low overlap) and complex cells (high overlap) in primary and secondary visual areas.NEW & NOTEWORTHY In the current study, we examine the relationship between the tuning of neural responses evoked by the onset and offset of acoustic stimuli in the primary auditory cortex, as well as a higher-order auditory area-the caudolateral belt field-in awake rhesus macaques. In these areas, the relationship between onset and offset response profiles in frequency and space domains formed a continuum, ranging from highly overlapping to highly nonoverlapping.
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Affiliation(s)
- Deepa L Ramamurthy
- Center for Neuroscience, University of California, Davis, California; and
| | - Gregg H Recanzone
- Center for Neuroscience, University of California, Davis, California; and.,Department of Neurobiology, Physiology and Behavior, University of California, Davis, California
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40
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The Effects of Urethane on Rat Outer Hair Cells. Neural Plast 2016; 2016:3512098. [PMID: 28050287 PMCID: PMC5165230 DOI: 10.1155/2016/3512098] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2016] [Accepted: 10/16/2016] [Indexed: 11/17/2022] Open
Abstract
The cochlea converts sound vibration into electrical impulses and amplifies the low-level sound signal. Urethane, a widely used anesthetic in animal research, has been shown to reduce the neural responses to auditory stimuli. However, the effects of urethane on cochlea, especially on the function of outer hair cells, remain largely unknown. In the present study, we compared the cochlear microphonic responses between awake and urethane-anesthetized rats. The results revealed that the amplitude of the cochlear microphonic was decreased by urethane, resulting in an increase in the threshold at all of the sound frequencies examined. To deduce the possible mechanism underlying the urethane-induced decrease in cochlear sensitivity, we examined the electrical response properties of isolated outer hair cells using whole-cell patch-clamp recording. We found that urethane hyperpolarizes the outer hair cell membrane potential in a dose-dependent manner and elicits larger outward current. This urethane-induced outward current was blocked by strychnine, an antagonist of the α9 subunit of the nicotinic acetylcholine receptor. Meanwhile, the function of the outer hair cell motor protein, prestin, was not affected. These results suggest that urethane anesthesia is expected to decrease the responses of outer hair cells, whereas the frequency selectivity of cochlea remains unchanged.
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Neural response differences in the rat primary auditory cortex under anesthesia with ketamine versus the mixture of medetomidine, midazolam and butorphanol. Hear Res 2016; 339:69-79. [DOI: 10.1016/j.heares.2016.06.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Revised: 06/08/2016] [Accepted: 06/15/2016] [Indexed: 11/18/2022]
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Insanally M, Trumpis M, Wang C, Chiang CH, Woods V, Palopoli-Trojani K, Bossi S, Froemke RC, Viventi J. A low-cost, multiplexed μECoG system for high-density recordings in freely moving rodents. J Neural Eng 2016; 13:026030-26030. [PMID: 26975462 DOI: 10.1088/1741-2560/13/2/026030] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE Micro-electrocorticography (μECoG) offers a minimally invasive neural interface with high spatial resolution over large areas of cortex. However, electrode arrays with many contacts that are individually wired to external recording systems are cumbersome and make recordings in freely behaving rodents challenging. We report a novel high-density 60-electrode system for μECoG recording in freely moving rats. APPROACH Multiplexed headstages overcome the problem of wiring complexity by combining signals from many electrodes to a smaller number of connections. We have developed a low-cost, multiplexed recording system with 60 contacts at 406 μm spacing. We characterized the quality of the electrode signals using multiple metrics that tracked spatial variation, evoked-response detectability, and decoding value. Performance of the system was validated both in anesthetized animals and freely moving awake animals. MAIN RESULTS We recorded μECoG signals over the primary auditory cortex, measuring responses to acoustic stimuli across all channels. Single-trial responses had high signal-to-noise ratios (SNR) (up to 25 dB under anesthesia), and were used to rapidly measure network topography within ∼10 s by constructing all single-channel receptive fields in parallel. We characterized evoked potential amplitudes and spatial correlations across the array in the anesthetized and awake animals. Recording quality in awake animals was stable for at least 30 days. Finally, we used these responses to accurately decode auditory stimuli on single trials. SIGNIFICANCE This study introduces (1) a μECoG recording system based on practical hardware design and (2) a rigorous analytical method for characterizing the signal characteristics of μECoG electrode arrays. This methodology can be applied to evaluate the fidelity and lifetime of any μECoG electrode array. Our μECoG-based recording system is accessible and will be useful for studies of perception and decision-making in rodents, particularly over the entire time course of behavioral training and learning.
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Affiliation(s)
- Michele Insanally
- Skirball Institute for Biomolecular Medicine, Neuroscience Institute, Departments of Otolaryngology, Neuroscience and Physiology, New York University School of Medicine, New York, NY, USA.,Center for Neural Science, New York University, New York, NY, USA
| | - Michael Trumpis
- Polytechnic Institute of New York University, Department of Electrical and Computer Engineering, New York, NY, USA.,Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Charles Wang
- Polytechnic Institute of New York University, Department of Electrical and Computer Engineering, New York, NY, USA.,Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Chia-Han Chiang
- Polytechnic Institute of New York University, Department of Electrical and Computer Engineering, New York, NY, USA.,Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Virginia Woods
- Polytechnic Institute of New York University, Department of Electrical and Computer Engineering, New York, NY, USA.,Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | | | - Silvia Bossi
- Department of Biomedical Engineering, Duke University, Durham, NC, USA.,Robotics Laboratory, C.R. Casaccia, ENEA, V. Anguillarese, 301, 00123 S. Maria di Galeria, Roma, Italy.,BioRobotics Institute, Scuola Superiore Sant'Anna, Viale Rinaldo Piaggio 34, 56025 Pontedera, Italy
| | - Robert C Froemke
- Skirball Institute for Biomolecular Medicine, Neuroscience Institute, Departments of Otolaryngology, Neuroscience and Physiology, New York University School of Medicine, New York, NY, USA.,Center for Neural Science, New York University, New York, NY, USA
| | - Jonathan Viventi
- Polytechnic Institute of New York University, Department of Electrical and Computer Engineering, New York, NY, USA.,Department of Biomedical Engineering, Duke University, Durham, NC, USA
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Topographic Distribution of Stimulus-Specific Adaptation across Auditory Cortical Fields in the Anesthetized Rat. PLoS Biol 2016; 14:e1002397. [PMID: 26950883 PMCID: PMC4780834 DOI: 10.1371/journal.pbio.1002397] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Accepted: 02/01/2016] [Indexed: 01/06/2023] Open
Abstract
Stimulus-specific adaptation (SSA) in single neurons of the auditory cortex was suggested to be a potential neural correlate of the mismatch negativity (MMN), a widely studied component of the auditory event-related potentials (ERP) that is elicited by changes in the auditory environment. However, several aspects on this SSA/MMN relation remain unresolved. SSA occurs in the primary auditory cortex (A1), but detailed studies on SSA beyond A1 are lacking. To study the topographic organization of SSA, we mapped the whole rat auditory cortex with multiunit activity recordings, using an oddball paradigm. We demonstrate that SSA occurs outside A1 and differs between primary and nonprimary cortical fields. In particular, SSA is much stronger and develops faster in the nonprimary than in the primary fields, paralleling the organization of subcortical SSA. Importantly, strong SSA is present in the nonprimary auditory cortex within the latency range of the MMN in the rat and correlates with an MMN-like difference wave in the simultaneously recorded local field potentials (LFP). We present new and strong evidence linking SSA at the cellular level to the MMN, a central tool in cognitive and clinical neuroscience. This study of higher-order auditory cortex strengthens the case for long-latency stimulus-specific adaptation as a genuine neural correlate of the mismatch negativity, which flags salient stimuli. Sensory systems automatically detect salient events in a monotonous ambient background. In humans, this change detection process is indexed by the mismatch negativity (MMN), a mid-late component of the auditory-evoked potentials that has become a central tool in cognitive and clinical neuroscience over the last 40 years. However, the neuronal correlate of MMN remains controversial. Stimulus-specific adaptation (SSA) is a special type of adaptation recorded at the neuronal level in the auditory pathway. Attenuating the response only to repetitive, background stimuli is a very efficient mechanism to enhance the saliency of any upcoming deviant or novel stimulus. Thus, SSA was originally proposed as a neural correlate of the MMN, but previous studies in the auditory cortex reported SSA only at very early latencies (circa 20–30 ms) and only within the primary auditory cortex (A1), whereas MMN analogs in the rat occur later, between 50 and 100 ms after change onset, and are generated mainly within nonprimary fields. Here, we report very strong SSA in nonprimary fields within the latency range of the MMN in the rat, providing empirical evidence of the missing link between single neuron response studies in animal models and the human MMN.
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Bigelow J, Ng CW, Poremba A. Local field potential correlates of auditory working memory in primate dorsal temporal pole. Brain Res 2015; 1640:299-313. [PMID: 26718730 DOI: 10.1016/j.brainres.2015.12.025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2015] [Revised: 12/06/2015] [Accepted: 12/14/2015] [Indexed: 10/22/2022]
Abstract
Dorsal temporal pole (dTP) is a cortical region at the rostral end of the superior temporal gyrus that forms part of the ventral auditory object processing pathway. Anatomical connections with frontal and medial temporal areas, as well as a recent single-unit recording study, suggest this area may be an important part of the network underlying auditory working memory (WM). To further elucidate the role of dTP in auditory WM, local field potentials (LFPs) were recorded from the left dTP region of two rhesus macaques during an auditory delayed matching-to-sample (DMS) task. Sample and test sounds were separated by a 5-s retention interval, and a behavioral response was required only if the sounds were identical (match trials). Sensitivity of auditory evoked responses in dTP to behavioral significance and context was further tested by passively presenting the sounds used as auditory WM memoranda both before and after the DMS task. Average evoked potentials (AEPs) for all cue types and phases of the experiment comprised two small-amplitude early onset components (N20, P40), followed by two broad, large-amplitude components occupying the remainder of the stimulus period (N120, P300), after which a final set of components were observed following stimulus offset (N80OFF, P170OFF). During the DMS task, the peak amplitude and/or latency of several of these components depended on whether the sound was presented as the sample or test, and whether the test matched the sample. Significant differences were also observed among the DMS task and passive exposure conditions. Comparing memory-related effects in the LFP signal with those obtained in the spiking data raises the possibility some memory-related activity in dTP may be locally produced and actively generated. The results highlight the involvement of dTP in auditory stimulus identification and recognition and its sensitivity to the behavioral significance of sounds in different contexts. This article is part of a Special Issue entitled SI: Auditory working memory.
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Affiliation(s)
- James Bigelow
- Department of Psychological and Brain Sciences, University of Iowa, 11 Seashore Hall East, Iowa City, IA 52242, United States.
| | - Chi-Wing Ng
- Center for Neuroscience University of California, Davis, CA 95616, United States.
| | - Amy Poremba
- Department of Psychological and Brain Sciences, University of Iowa, 11 Seashore Hall East, Iowa City, IA 52242, United States.
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Thorson IL, Liénard J, David SV. The Essential Complexity of Auditory Receptive Fields. PLoS Comput Biol 2015; 11:e1004628. [PMID: 26683490 PMCID: PMC4684325 DOI: 10.1371/journal.pcbi.1004628] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 10/26/2015] [Indexed: 12/05/2022] Open
Abstract
Encoding properties of sensory neurons are commonly modeled using linear finite impulse response (FIR) filters. For the auditory system, the FIR filter is instantiated in the spectro-temporal receptive field (STRF), often in the framework of the generalized linear model. Despite widespread use of the FIR STRF, numerous formulations for linear filters are possible that require many fewer parameters, potentially permitting more efficient and accurate model estimates. To explore these alternative STRF architectures, we recorded single-unit neural activity from auditory cortex of awake ferrets during presentation of natural sound stimuli. We compared performance of > 1000 linear STRF architectures, evaluating their ability to predict neural responses to a novel natural stimulus. Many were able to outperform the FIR filter. Two basic constraints on the architecture lead to the improved performance: (1) factorization of the STRF matrix into a small number of spectral and temporal filters and (2) low-dimensional parameterization of the factorized filters. The best parameterized model was able to outperform the full FIR filter in both primary and secondary auditory cortex, despite requiring fewer than 30 parameters, about 10% of the number required by the FIR filter. After accounting for noise from finite data sampling, these STRFs were able to explain an average of 40% of A1 response variance. The simpler models permitted more straightforward interpretation of sensory tuning properties. They also showed greater benefit from incorporating nonlinear terms, such as short term plasticity, that provide theoretical advances over the linear model. Architectures that minimize parameter count while maintaining maximum predictive power provide insight into the essential degrees of freedom governing auditory cortical function. They also maximize statistical power available for characterizing additional nonlinear properties that limit current auditory models. Understanding how the brain solves sensory problems can provide useful insight for the development of automated systems such as speech recognizers and image classifiers. Recent developments in nonlinear regression and machine learning have produced powerful algorithms for characterizing the input-output relationship of complex systems. However, the complexity of sensory neural systems, combined with practical limitations on experimental data, make it difficult to apply arbitrarily complex analyses to neural data. In this study we pushed analysis in the opposite direction, toward simpler models. We asked how simple a model can be while still capturing the essential sensory properties of neurons in auditory cortex. We found that substantially simpler formulations of the widely-used spectro-temporal receptive field are able to perform as well as the best current models. These simpler formulations define new basis sets that can be incorporated into state-of-the-art machine learning algorithms for a more exhaustive exploration of sensory processing.
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Affiliation(s)
- Ivar L. Thorson
- Oregon Hearing Research Center, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Jean Liénard
- Department of Mathematics, Washington State University, Vancouver, Washington, United States of America
| | - Stephen V. David
- Oregon Hearing Research Center, Oregon Health & Science University, Portland, Oregon, United States of America
- * E-mail:
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Natan RG, Briguglio JJ, Mwilambwe-Tshilobo L, Jones SI, Aizenberg M, Goldberg EM, Geffen MN. Complementary control of sensory adaptation by two types of cortical interneurons. eLife 2015; 4. [PMID: 26460542 PMCID: PMC4641469 DOI: 10.7554/elife.09868] [Citation(s) in RCA: 128] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2015] [Accepted: 10/01/2015] [Indexed: 01/14/2023] Open
Abstract
Reliably detecting unexpected sounds is important for environmental awareness and survival. By selectively reducing responses to frequently, but not rarely, occurring sounds, auditory cortical neurons are thought to enhance the brain's ability to detect unexpected events through stimulus-specific adaptation (SSA). The majority of neurons in the primary auditory cortex exhibit SSA, yet little is known about the underlying cortical circuits. We found that two types of cortical interneurons differentially amplify SSA in putative excitatory neurons. Parvalbumin-positive interneurons (PVs) amplify SSA by providing non-specific inhibition: optogenetic suppression of PVs led to an equal increase in responses to frequent and rare tones. In contrast, somatostatin-positive interneurons (SOMs) selectively reduce excitatory responses to frequent tones: suppression of SOMs led to an increase in responses to frequent, but not to rare tones. A mutually coupled excitatory-inhibitory network model accounts for distinct mechanisms by which cortical inhibitory neurons enhance the brain's sensitivity to unexpected sounds. DOI:http://dx.doi.org/10.7554/eLife.09868.001 In everyday life, we are often exposed to a mix of different sounds. An essential task for our brain is to separate the important sounds from the unimportant ones. For example, stepping out onto a busy street, you may at first be very aware of the noise of traffic. Later, you may start to ignore the din and instead only notice sounds that break the monotony: a honking car horn or maybe a stranger's voice. This is because the neurons in the auditory pathway respond differently to common and rare sounds. In particular, excitatory neurons in the region termed the ‘auditory cortex’ send fewer nerve impulses in response to frequent sounds, but respond vigorously to rare sounds. This phenomenon is called ‘stimulus-specific adaptation’, but it is not known exactly which neurons in this brain region enable this process to occur. Now, Natan et al. have combined different cutting-edge neuroscience techniques to identify the circuit of brain cells that drives this stimulus specific adaptation. A technique called optogenetics was used to effectively ‘turn off’ each of two kinds of inhibitory neuron in the auditory cortex of mice, by exposing the brain to colored light from a laser. Natan et al. found that both kinds of inhibitory neuron amplified stimulus-specific adaptation, but via different mechanisms. One of these neuron types, called ‘parvalbumin-positive interneurons’, exerted a general effect on excitatory neurons and suppressed responses to both frequent and rare sounds As the responses to rare sounds started off greater than the responses to frequent sounds, suppressing both by an equal amount actually led to an increase in the relative difference between them. On the other hand, the second kind of inhibitory neuron, called ‘somatostatin-positive interneurons’, only reduced the excitatory neurons' responses to frequent sounds; these neurons had no effect on responses to rare noises. Future studies will test how specific adaptation in different contexts can help us to behaviorally detect rare sounds while ignoring common ones, and search for the circuits beyond the auditory cortex that support hearing in complex sound environments. DOI:http://dx.doi.org/10.7554/eLife.09868.002
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Affiliation(s)
- Ryan G Natan
- Department of Otorhinolaryngology Head and Neck Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
| | - John J Briguglio
- Department of Otorhinolaryngology Head and Neck Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
| | - Laetitia Mwilambwe-Tshilobo
- Department of Otorhinolaryngology Head and Neck Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
| | - Sara I Jones
- Department of Otorhinolaryngology Head and Neck Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
| | - Mark Aizenberg
- Department of Otorhinolaryngology Head and Neck Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
| | - Ethan M Goldberg
- Department of Neurology, University of Pennsylvania, Philadelphia, United States.,Division of Neurology, The Children's Hospital of Philadelphia, Philadelphia, United States
| | - Maria Neimark Geffen
- Department of Otorhinolaryngology Head and Neck Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
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Schaefer MK, Hechavarría JC, Kössl M. Quantification of mid and late evoked sinks in laminar current source density profiles of columns in the primary auditory cortex. Front Neural Circuits 2015; 9:52. [PMID: 26557058 PMCID: PMC4617414 DOI: 10.3389/fncir.2015.00052] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 09/14/2015] [Indexed: 11/18/2022] Open
Abstract
Current source density (CSD) analysis assesses spatiotemporal synaptic activations at somatic and/or dendritic levels in the form of depolarizing current sinks. Whereas many studies have focused on the short (<50 ms) latency sinks, associated with thalamocortical projections, sinks with longer latencies have received less attention. Here, we analyzed laminar CSD patterns for the first 600 ms after stimulus onset in the primary auditory cortex of Mongolian gerbils. By applying an algorithm for contour calculation, three distinct mid and four late evoked sinks were identified in layers I, III, Va, VIa, and VIb. Our results further showed that the patterns of intracortical information-flow remained qualitatively similar for low and for high sound pressure level stimuli at the characteristic frequency (CF) as well as for stimuli ± 1 octave from CF. There were, however, differences associated with the strength, vertical extent, onset latency, and duration of the sinks for the four stimulation paradigms used. Stimuli one octave above the most sensitive frequency evoked a new, and quite reliable, sink in layer Va whereas low level stimulation led to the disappearance of the layer VIb sink. These data indicate the presence of input sources specifically activated in response to level and/or frequency parameters. Furthermore, spectral integration above vs. below the CF of neurons is asymmetric as illustrated by CSD profiles. These results are important because synaptic feedback associated with mid and late sinks—beginning at 50 ms post stimulus latency—is likely crucial for response modulation resulting from higher order processes like memory, learning or cognitive control.
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Affiliation(s)
- Markus K Schaefer
- Institute for Cell Biology and Neuroscience, AK Neurobiology and Biosensors, Goethe University Frankfurt/Main, Germany
| | - Julio C Hechavarría
- Institute for Cell Biology and Neuroscience, AK Neurobiology and Biosensors, Goethe University Frankfurt/Main, Germany
| | - Manfred Kössl
- Institute for Cell Biology and Neuroscience, AK Neurobiology and Biosensors, Goethe University Frankfurt/Main, Germany
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Noda T, Takahashi H. Anesthetic effects of isoflurane on the tonotopic map and neuronal population activity in the rat auditory cortex. Eur J Neurosci 2015; 42:2298-311. [PMID: 26118739 DOI: 10.1111/ejn.13007] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Revised: 06/23/2015] [Accepted: 06/24/2015] [Indexed: 12/01/2022]
Abstract
Since its discovery nearly four decades ago, sequential microelectrode mapping using hundreds of recording sites has been able to reveal a precise tonotopic organization of the auditory cortex. Despite concerns regarding the effects that anesthesia might have on neuronal responses to tones, anesthesia was essential for these experiments because such dense mapping was elaborate and time-consuming. Here, taking an 'all-at-once' approach, we investigated how isoflurane modifies spatiotemporal activities by using a dense microelectrode array. The array covered the entire auditory cortex in rats, including the core and belt cortices. By comparing neuronal activity in the awake state with activity under isoflurane anesthesia, we made four observations. First, isoflurane anesthesia did not modify the tonotopic topography within the auditory cortex. Second, in terms of general response properties, isoflurane anesthesia decreased the number of active single units and increased their response onset latency. Third, in terms of tuning properties, isoflurane anesthesia shifted the response threshold without changing the shape of the frequency response area and decreased the response quality. Fourth, in terms of population activities, isoflurane anesthesia increased the noise correlations in discharges and phase synchrony in local field potential (LFP) oscillations, suggesting that the anesthesia made neuronal activities redundant at both single-unit and LFP levels. Thus, while isoflurane anesthesia had little effect on the tonotopic topography, its profound effects on neuronal activities decreased the encoding capacity of the auditory cortex.
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Affiliation(s)
- Takahiro Noda
- Research Center for Advanced Science and Technology, The University of Tokyo, Komaba 4-6-1, Meguro-ku, Tokyo, 153-8904, Japan
| | - Hirokazu Takahashi
- Research Center for Advanced Science and Technology, The University of Tokyo, Komaba 4-6-1, Meguro-ku, Tokyo, 153-8904, Japan.,PRESTO, JST, Kawaguchi, Saitama, Japan
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Jiang C, Xu X, Yu L, Xu J, Zhang J. Environmental enrichment rescues the degraded auditory temporal resolution of cortical neurons induced by early noise exposure. Eur J Neurosci 2015; 42:2144-54. [DOI: 10.1111/ejn.12975] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2015] [Revised: 06/02/2015] [Accepted: 06/02/2015] [Indexed: 12/26/2022]
Affiliation(s)
- Cuiping Jiang
- Key Laboratory of Brain Functional Genomics; Ministry of Education; Shanghai Key Laboratory of Brain Functional Genomics; NYU-ECNU Institute of Brain and Cognitive Science at NYU Shanghai; School of Life Sciences; East China Normal University; Shanghai 200062 China
| | - Xiaoxiao Xu
- Key Laboratory of Brain Functional Genomics; Ministry of Education; Shanghai Key Laboratory of Brain Functional Genomics; NYU-ECNU Institute of Brain and Cognitive Science at NYU Shanghai; School of Life Sciences; East China Normal University; Shanghai 200062 China
| | - Liping Yu
- Key Laboratory of Brain Functional Genomics; Ministry of Education; Shanghai Key Laboratory of Brain Functional Genomics; NYU-ECNU Institute of Brain and Cognitive Science at NYU Shanghai; School of Life Sciences; East China Normal University; Shanghai 200062 China
| | - Jinghong Xu
- Key Laboratory of Brain Functional Genomics; Ministry of Education; Shanghai Key Laboratory of Brain Functional Genomics; NYU-ECNU Institute of Brain and Cognitive Science at NYU Shanghai; School of Life Sciences; East China Normal University; Shanghai 200062 China
| | - Jiping Zhang
- Key Laboratory of Brain Functional Genomics; Ministry of Education; Shanghai Key Laboratory of Brain Functional Genomics; NYU-ECNU Institute of Brain and Cognitive Science at NYU Shanghai; School of Life Sciences; East China Normal University; Shanghai 200062 China
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50
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High-field functional magnetic resonance imaging of vocalization processing in marmosets. Sci Rep 2015; 5:10950. [PMID: 26091254 PMCID: PMC4473644 DOI: 10.1038/srep10950] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Accepted: 04/29/2015] [Indexed: 11/17/2022] Open
Abstract
Vocalizations are behaviorally critical sounds, and this behavioral importance is reflected in the ascending auditory system, where conspecific vocalizations are increasingly over-represented at higher processing stages. Recent evidence suggests that, in macaques, this increasing selectivity for vocalizations might culminate in a cortical region that is densely populated by vocalization-preferring neurons. Such a region might be a critical node in the representation of vocal communication sounds, underlying the recognition of vocalization type, caller and social context. These results raise the questions of whether cortical specializations for vocalization processing exist in other species, their cortical location, and their relationship to the auditory processing hierarchy. To explore cortical specializations for vocalizations in another species, we performed high-field fMRI of the auditory cortex of a vocal New World primate, the common marmoset (Callithrix jacchus). Using a sparse imaging paradigm, we discovered a caudal-rostral gradient for the processing of conspecific vocalizations in marmoset auditory cortex, with regions of the anterior temporal lobe close to the temporal pole exhibiting the highest preference for vocalizations. These results demonstrate similar cortical specializations for vocalization processing in macaques and marmosets, suggesting that cortical specializations for vocal processing might have evolved before the lineages of these species diverged.
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