51
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Tracking Down Nonresponsive Cortical Neurons in Cochlear Implant Stimulation. eNeuro 2017; 4:eN-COM-0095-17. [PMID: 28660249 PMCID: PMC5485376 DOI: 10.1523/eneuro.0095-17.2017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 06/13/2017] [Accepted: 06/15/2017] [Indexed: 11/21/2022] Open
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52
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Lauer AM, Behrens D, Klump G. Acoustic startle modification as a tool for evaluating auditory function of the mouse: Progress, pitfalls, and potential. Neurosci Biobehav Rev 2017; 77:194-208. [PMID: 28327385 PMCID: PMC5446932 DOI: 10.1016/j.neubiorev.2017.03.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Revised: 02/23/2017] [Accepted: 03/13/2017] [Indexed: 12/16/2022]
Abstract
Acoustic startle response (ASR) modification procedures, especially prepulse inhibition (PPI), are increasingly used as behavioral measures of auditory processing and sensorimotor gating in rodents due to their perceived ease of implementation and short testing times. In practice, ASR and PPI procedures are extremely variable across animals, experimental setups, and studies, and the interpretation of results is subject to numerous caveats and confounding influences. We review considerations for modification of the ASR using acoustic stimuli, and we compare the sensitivity of PPI procedures to more traditional operant psychoacoustic techniques. We also discuss non-auditory variables that must be considered. We conclude that ASR and PPI measures cannot substitute for traditional operant techniques due to their low sensitivity. Additionally, a substantial amount of pilot testing must be performed to properly optimize an ASR modification experiment, negating any time benefit over operant conditioning. Nevertheless, there are some circumstances where ASR measures may be the only option for assessing auditory behavior, such as when testing mouse strains with early-onset hearing loss or learning impairments.
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Affiliation(s)
- Amanda M Lauer
- Department of Otolaryngology-Head and Neck Surgery and Center for Hearing and Balance, Johns Hopkins University, 515 Traylor Building, 720 Rutland Ave., Baltimore, MD 21205, USA.
| | - Derik Behrens
- Cluster of Excellence Hearing4all, Animal Physiology & Behavior Group, Department for Neuroscience, School of Medicine and Health Sciences, Carl Von Ossietzky University Oldenburg, Carl Von Ossietzky Str. 9-11, 26111 Oldenburg, Germany
| | - Georg Klump
- Cluster of Excellence Hearing4all, Animal Physiology & Behavior Group, Department for Neuroscience, School of Medicine and Health Sciences, Carl Von Ossietzky University Oldenburg, Carl Von Ossietzky Str. 9-11, 26111 Oldenburg, Germany
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53
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Natan RG, Carruthers IM, Mwilambwe-Tshilobo L, Geffen MN. Gain Control in the Auditory Cortex Evoked by Changing Temporal Correlation of Sounds. Cereb Cortex 2017; 27:2385-2402. [PMID: 27095823 DOI: 10.1093/cercor/bhw083] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Natural sounds exhibit statistical variation in their spectrotemporal structure. This variation is central to identification of unique environmental sounds and to vocal communication. Using limited resources, the auditory system must create a faithful representation of sounds across the full range of variation in temporal statistics. Imaging studies in humans demonstrated that the auditory cortex is sensitive to temporal correlations. However, the mechanisms by which the auditory cortex represents the spectrotemporal structure of sounds and how neuronal activity adjusts to vastly different statistics remain poorly understood. In this study, we recorded responses of neurons in the primary auditory cortex of awake rats to sounds with systematically varied temporal correlation, to determine whether and how this feature alters sound encoding. Neuronal responses adapted to changing stimulus temporal correlation. This adaptation was mediated by a change in the firing rate gain of neuronal responses rather than their spectrotemporal properties. This gain adaptation allowed neurons to maintain similar firing rates across stimuli with different statistics, preserving their ability to efficiently encode temporal modulation. This dynamic gain control mechanism may underlie comprehension of vocalizations and other natural sounds under different contexts, subject to distortions in temporal correlation structure via stretching or compression.
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Affiliation(s)
- Ryan G Natan
- Department of Otorhinolaryngology and Head and Neck Surgery.,Graduate Group in Neuroscience
| | - Isaac M Carruthers
- Department of Otorhinolaryngology and Head and Neck Surgery.,Graduate Group in Physics
| | | | - Maria N Geffen
- Department of Otorhinolaryngology and Head and Neck Surgery.,Graduate Group in Neuroscience.,Graduate Group in Physics.,Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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54
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Okamoto H, Kakigi R. Modulation of Auditory Evoked Magnetic Fields Elicited by Successive Frequency-Modulated (FM) Sweeps. Front Hum Neurosci 2017; 11:36. [PMID: 28220066 PMCID: PMC5292620 DOI: 10.3389/fnhum.2017.00036] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 01/17/2017] [Indexed: 11/13/2022] Open
Abstract
In our daily life, we are successively exposed to frequency-modulated (FM) sounds that play an important role in speech and species-specific communication. Previous studies demonstrated that repetitive exposure to identical pure tones resulted in decreased neural activity. However, the effects of repetitively presented FM sounds on neural activity in the human auditory cortex remain unclear. In the present study, we used magnetoencephalography to investigate auditory evoked N1m responses elicited by four successive temporally repeated and superimposed FM sweeps in three sequences: (1) four FM sweeps were identical, (2) four FM sweeps had the same FM direction and rate, but different carrier frequencies, (3) four FM sweeps differed with respect to the FM rate and/or direction and their carrier frequencies. In contrast to our expectations, the results obtained demonstrated that N1m responses were maximal when the four FM sweeps were identical and minimal when they were distinct. These results suggest that the neural processing of repetitive FM sweeps in the human auditory cortex may differ from that of repetitive pure tones.
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Affiliation(s)
- Hidehiko Okamoto
- Department of Integrative Physiology, National Institute for Physiological SciencesOkazaki, Japan
- Department of Physiological Sciences, Graduate University for Advanced StudiesHayama, Japan
- *Correspondence: Hidehiko Okamoto
| | - Ryusuke Kakigi
- Department of Integrative Physiology, National Institute for Physiological SciencesOkazaki, Japan
- Department of Physiological Sciences, Graduate University for Advanced StudiesHayama, Japan
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55
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Sekiya K, Takahashi M, Murakami S, Kakigi R, Okamoto H. Broadened population-level frequency tuning in the auditory cortex of tinnitus patients. J Neurophysiol 2017; 117:1379-1384. [PMID: 28053240 PMCID: PMC5350267 DOI: 10.1152/jn.00385.2016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 12/29/2016] [Accepted: 12/31/2016] [Indexed: 11/22/2022] Open
Abstract
Although subjective tinnitus is one of the most common public health concerns that impair the quality of life of many individuals, no standard treatment or objective diagnostic method currently exists. We herein revealed that population-level frequency tuning was significantly broader in the tinnitus ear than in the nontinnitus ear. The results of the present study provide an insight into the development of an objective diagnostic method for subjective tinnitus. Tinnitus is a phantom auditory perception without an external sound source and is one of the most common public health concerns that impair the quality of life of many individuals. However, its neural mechanisms remain unclear. We herein examined population-level frequency tuning in the auditory cortex of unilateral tinnitus patients with similar hearing levels in both ears using magnetoencephalography. We compared auditory-evoked neural activities elicited by a stimulation to the tinnitus and nontinnitus ears. Objective magnetoencephalographic data suggested that population-level frequency tuning corresponding to the tinnitus ear was significantly broader than that corresponding to the nontinnitus ear in the human auditory cortex. The results obtained support the hypothesis that pathological alterations in inhibitory neural networks play an important role in the perception of subjective tinnitus. NEW & NOTEWORTHY Although subjective tinnitus is one of the most common public health concerns that impair the quality of life of many individuals, no standard treatment or objective diagnostic method currently exists. We herein revealed that population-level frequency tuning was significantly broader in the tinnitus ear than in the nontinnitus ear. The results of the present study provide an insight into the development of an objective diagnostic method for subjective tinnitus.
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Affiliation(s)
- Kenichi Sekiya
- Department of Integrative Physiology, National Institute for Physiological Sciences, Okazaki, Japan.,Department of Otolaryngology, Head, and Neck Surgery, Nagoya City University Graduate School of Medical Sciences and Medical School, Nagoya, Japan; and
| | - Mariko Takahashi
- Department of Otolaryngology, Head, and Neck Surgery, Nagoya City University Graduate School of Medical Sciences and Medical School, Nagoya, Japan; and
| | - Shingo Murakami
- Department of Otolaryngology, Head, and Neck Surgery, Nagoya City University Graduate School of Medical Sciences and Medical School, Nagoya, Japan; and
| | - Ryusuke Kakigi
- Department of Integrative Physiology, National Institute for Physiological Sciences, Okazaki, Japan.,The Graduate University for Advanced Studies (SOKENDAI), Hayama, Japan
| | - Hidehiko Okamoto
- Department of Integrative Physiology, National Institute for Physiological Sciences, Okazaki, Japan; .,The Graduate University for Advanced Studies (SOKENDAI), Hayama, Japan
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56
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Wigestrand MB, Schiff HC, Fyhn M, LeDoux JE, Sears RM. Primary auditory cortex regulates threat memory specificity. Learn Mem 2017; 24:55-58. [PMID: 27980076 PMCID: PMC5159661 DOI: 10.1101/lm.044362.116] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 10/24/2016] [Indexed: 01/26/2023]
Abstract
Distinguishing threatening from nonthreatening stimuli is essential for survival and stimulus generalization is a hallmark of anxiety disorders. While auditory threat learning produces long-lasting plasticity in primary auditory cortex (Au1), it is not clear whether such Au1 plasticity regulates memory specificity or generalization. We used muscimol infusions in rats to show that discriminatory threat learning requires Au1 activity specifically during memory acquisition and retrieval, but not during consolidation. Memory specificity was similarly disrupted by infusion of PKMζ inhibitor peptide (ZIP) during memory storage. Our findings show that Au1 is required at critical memory phases and suggest that Au1 plasticity enables stimulus discrimination.
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Affiliation(s)
- Mattis B Wigestrand
- Center for Neuroscience, New York University, New York, New York 10003, USA
- Department of Molecular Biosciences, University of Oslo, 0371 Oslo, Norway
| | - Hillary C Schiff
- Center for Neuroscience, New York University, New York, New York 10003, USA
| | - Marianne Fyhn
- Department of Molecular Biosciences, University of Oslo, 0371 Oslo, Norway
| | - Joseph E LeDoux
- Center for Neuroscience, New York University, New York, New York 10003, USA
- Emotional Brain Institute, Nathan Kline Institute for Psychiatric Research, Orangeburg, New York 10962, USA
| | - Robert M Sears
- Center for Neuroscience, New York University, New York, New York 10003, USA
- Emotional Brain Institute, Nathan Kline Institute for Psychiatric Research, Orangeburg, New York 10962, USA
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57
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Phillips EA, Hasenstaub AR. Asymmetric effects of activating and inactivating cortical interneurons. eLife 2016; 5. [PMID: 27719761 PMCID: PMC5123863 DOI: 10.7554/elife.18383] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 10/09/2016] [Indexed: 11/16/2022] Open
Abstract
Bidirectional manipulations – activation and inactivation – are widely used to identify the functions supported by specific cortical interneuron types. Implicit in much of this work is the notion that tonic activation and inactivation will both produce valid, internally consistent insights into interneurons’ computational roles. Here, using single-unit recordings in auditory cortex of awake mice, we show that this may not generally hold true. Optogenetically manipulating somatostatin-positive (Sst+) or parvalbumin-positive (Pvalb+) interneurons while recording tone-responses showed that Sst+ inactivation increased response gain, while Pvalb+ inactivation weakened tuning and decreased information transfer, implying that these neurons support delineable computational functions. But activating Sst+ and Pvalb+ interneurons revealed no such differences. We used a simple network model to understand this asymmetry, and showed how relatively small changes in key parameters, such as spontaneous activity or strength of the light manipulation, determined whether activation and inactivation would produce consistent or paradoxical conclusions regarding interneurons’ computational functions. DOI:http://dx.doi.org/10.7554/eLife.18383.001 The brain processes information through the activity of many different types of neurons. A common assumption is that we can work out the role of each type of neuron by increasing or decreasing its activity experimentally and observing the consequences. Imagine, for example, that increasing the activity of a group of neurons boosts the formation of memories, whereas decreasing their activity has the opposite effect. Can we conclude that the natural role of those neurons is to support memory formation? This question has become increasingly pertinent in recent years, as advances in molecular genetic techniques such as optogenetics have made it easier to experimentally manipulate the activity of neurons. However, the ease with which these experiments can be done masks how difficult it can be to interpret the results. To test the assumption that dialing a neuron’s activity up or down provides a straightforward readout of its role in the brain, Phillips and Hasenstaub used optogenetics to inactivate two types of neurons in an area of the mouse brain responsible for processing sound. Inactivating each cell type produced different outcomes. The standard way of interpreting these results is to conclude that the neurons must therefore have different, separable roles. However, using optogenetics to increase the activity of the neurons revealed no such differences in the neurons’ roles. Using a computer model, Phillips and Hasenstaub showed that relatively small changes in factors such as the spontaneous activity of the neurons can affect the outcome of the experiments. Under certain circumstances, the two types of neurons respond in the same way to activation and inactivation; under other circumstances, they respond differently. The results presented by Phillips and Hasenstaub remind us that the conclusions we draw about a neuron’s role can be sensitive to how the cell was manipulated. Future studies should address how other aspects of experimental manipulations, such as their timing or pattern, affect the apparent behavior of neurons. DOI:http://dx.doi.org/10.7554/eLife.18383.002
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Affiliation(s)
- Elizabeth Ak Phillips
- Neuroscience Graduate Program, University of California, San Francisco, San Francisco, United States.,Center for Integrative Neuroscience, University of California San Francisco, San Francisco, United States.,Coleman Memorial Laboratory, University of California, San Francisco, San Francisco, United States.,Department of Otolaryngology-Head and Neck Surgery, University of California, San Francisco, San Francisco, United States
| | - Andrea R Hasenstaub
- Neuroscience Graduate Program, University of California, San Francisco, San Francisco, United States.,Center for Integrative Neuroscience, University of California San Francisco, San Francisco, United States.,Coleman Memorial Laboratory, University of California, San Francisco, San Francisco, United States.,Department of Otolaryngology-Head and Neck Surgery, University of California, San Francisco, San Francisco, United States
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58
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Blackwell JM, Taillefumier TO, Natan RG, Carruthers IM, Magnasco MO, Geffen MN. Stable encoding of sounds over a broad range of statistical parameters in the auditory cortex. Eur J Neurosci 2016; 43:751-64. [PMID: 26663571 PMCID: PMC5021175 DOI: 10.1111/ejn.13144] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Revised: 11/22/2015] [Accepted: 12/01/2015] [Indexed: 11/29/2022]
Abstract
Natural auditory scenes possess highly structured statistical regularities, which are dictated by the physics of sound production in nature, such as scale‐invariance. We recently identified that natural water sounds exhibit a particular type of scale invariance, in which the temporal modulation within spectral bands scales with the centre frequency of the band. Here, we tested how neurons in the mammalian primary auditory cortex encode sounds that exhibit this property, but differ in their statistical parameters. The stimuli varied in spectro‐temporal density and cyclo‐temporal statistics over several orders of magnitude, corresponding to a range of water‐like percepts, from pattering of rain to a slow stream. We recorded neuronal activity in the primary auditory cortex of awake rats presented with these stimuli. The responses of the majority of individual neurons were selective for a subset of stimuli with specific statistics. However, as a neuronal population, the responses were remarkably stable over large changes in stimulus statistics, exhibiting a similar range in firing rate, response strength, variability and information rate, and only minor variation in receptive field parameters. This pattern of neuronal responses suggests a potentially general principle for cortical encoding of complex acoustic scenes: while individual cortical neurons exhibit selectivity for specific statistical features, a neuronal population preserves a constant response structure across a broad range of statistical parameters.
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Affiliation(s)
- Jennifer M Blackwell
- Department of Otorhinolaryngology and Head and Neck Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Thibaud O Taillefumier
- Center for Physics and Biology, Rockefeller University, New York, NY, USA.,Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Ryan G Natan
- Department of Otorhinolaryngology and Head and Neck Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Isaac M Carruthers
- Department of Otorhinolaryngology and Head and Neck Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Marcelo O Magnasco
- Center for Physics and Biology, Rockefeller University, New York, NY, USA
| | - Maria N Geffen
- Department of Otorhinolaryngology and Head and Neck Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.,Center for Physics and Biology, Rockefeller University, New York, NY, USA
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