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Carr CE, Wang T, Kraemer I, Capshaw G, Ashida G, Köppl C, Kempter R, Kuokkanen PT. Experience-Dependent Plasticity in Nucleus Laminaris of the Barn Owl. J Neurosci 2024; 44:e0940232023. [PMID: 37989591 PMCID: PMC10851688 DOI: 10.1523/jneurosci.0940-23.2023] [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: 05/22/2023] [Revised: 10/12/2023] [Accepted: 11/01/2023] [Indexed: 11/23/2023] Open
Abstract
Interaural time differences (ITDs) are a major cue for sound localization and change with increasing head size. Since the barn owl's head width more than doubles in the month after hatching, we hypothesized that the development of their ITD detection circuit might be modified by experience. To test this, we raised owls with unilateral ear inserts that delayed and attenuated the acoustic signal, and then measured the ITD representation in the brainstem nucleus laminaris (NL) when they were adults. The ITD circuit is composed of delay line inputs to coincidence detectors, and we predicted that plastic changes would lead to shorter delays in the axons from the manipulated ear, and complementary shifts in ITD representation on the two sides. In owls that received ear inserts starting around P14, the maps of ITD shifted in the predicted direction, but only on the ipsilateral side, and only in those tonotopic regions that had not experienced auditory stimulation prior to insertion. The contralateral map did not change. Thus, experience-dependent plasticity of the ITD circuit occurs in NL, and our data suggest that ipsilateral and contralateral delays are independently regulated. As a result, altered auditory input during development leads to long-lasting changes in the representation of ITD.Significance Statement The early life of barn owls is marked by increasing sensitivity to sound, and by increasing ITDs. Their prolonged post-hatch development allowed us to examine the role of altered auditory experience in the development of ITD detection circuits. We raised owls with a unilateral ear insert and found that their maps of ITD were altered by experience, but only in those tonotopic regions ipsilateral to the occluded ear that had not experienced auditory stimulation prior to insertion. This experience-induced plasticity allows the sound localization circuits to be customized to individual characteristics, such as the size of the head, and potentially to compensate for imbalanced hearing sensitivities between the left and right ears.
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Affiliation(s)
- Catherine E Carr
- Department of Biology, University of Maryland College Park, College Park, MD 20742
| | - Tiffany Wang
- Department of Biology, University of Maryland College Park, College Park, MD 20742
| | - Ira Kraemer
- Department of Biology, University of Maryland College Park, College Park, MD 20742
| | - Grace Capshaw
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD 21218
| | - 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, 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, 26129 Oldenburg, Germany
| | - Richard Kempter
- Institute for Theoretical Biology, Department of Biology, Humboldt-Universität zu Berlin, 10115 Berlin, Germany
- Bernstein Center for Computational Neuroscience Berlin, 10115 Berlin, Germany
- Einstein Center for Neurosciences Berlin, 10117 Berlin, Germany
| | - Paula T Kuokkanen
- Department of Biology, University of Maryland College Park, College Park, MD 20742
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Carr CE, Wang T, Kraemer I, Capshaw G, Ashida G, Koeppl C, Kempter R, Kuokkanen PT. Experience-Dependent Plasticity in Nucleus Laminaris of the Barn Owl. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.02.526884. [PMID: 36778252 PMCID: PMC9915572 DOI: 10.1101/2023.02.02.526884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Barn owls experience increasing interaural time differences (ITDs) during development, because their head width more than doubles in the month after hatching. We therefore hypothesized that their ITD detection circuit might be modified by experience. To test this, we raised owls with unilateral ear inserts that delayed and attenuated the acoustic signal, then measured the ITD representation in the brainstem nucleus laminaris (NL) when they were adult. The ITD circuit is composed of delay line inputs to coincidence detectors, and we predicted that plastic changes would lead to shorter delays in the axons from the manipulated ear, and complementary shifts in ITD representation on the two sides. In owls that received ear inserts starting around P14, the maps of ITD shifted in the predicted direction, but only on the ipsilateral side, and only in those tonotopic regions that had not experienced auditory stimulation prior to insertion. The contralateral map did not change. Experience-dependent plasticity of the ITD circuit occurs in NL, and our data suggest that ipsilateral and contralateral delays are independently regulated. Thus, altered auditory input during development leads to long-lasting changes in the representation of ITD.
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McColgan T, Kuokkanen PT, Carr CE, Kempter R. Dynamics of synaptic extracellular field potentials in the nucleus laminaris of the barn owl. J Neurophysiol 2019; 121:1034-1047. [PMID: 30575430 DOI: 10.1152/jn.00648.2017] [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] [Indexed: 01/20/2023] Open
Abstract
Synaptic currents are frequently assumed to make a major contribution to the extracellular field potential (EFP). However, in any neuronal population, the explicit separation of synaptic sources from other contributions such as postsynaptic spikes remains a challenge. Here we take advantage of the simple organization of the barn owl nucleus laminaris (NL) in the auditory brain stem to isolate synaptic currents through the iontophoretic application of the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-receptor antagonist 1,2,3,4-tetrahydro-6-nitro-2,3-dioxo-benzo[ f]quinoxaline-7-sulfonamide (NBQX). Responses to auditory stimulation show that the temporal dynamics of the evoked synaptic contributions to the EFP are consistent with synaptic short-term depression (STD). The estimated time constants of an STD model fitted to the data are similar to the fast time constants reported from in vitro experiments in the chick. Overall, the putative synaptic EFPs in the barn owl NL are significant but small (<1% change of the variance by NBQX). This result supports the hypothesis that the EFP in NL is generated mainly by axonal spikes, in contrast to most other neuronal systems. NEW & NOTEWORTHY Synaptic currents are assumed to make a major contribution to the extracellular field potential in the brain, but it is hard to directly isolate these synaptic components. Here we take advantage of the simple organization of the barn owl nucleus laminaris in the auditory brain stem to isolate synaptic currents through the iontophoretic application of a synaptic blocker. We show that the responses are consistent with a simple model of short-term synaptic depression.
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Affiliation(s)
- Thomas McColgan
- Bernstein Center for Computational Neuroscience , Berlin , Germany.,Institute for Theoretical Biology, Department of Biology, Humboldt-Universität zu Berlin, Berlin , Germany
| | - Paula T Kuokkanen
- Bernstein Center for Computational Neuroscience , Berlin , Germany.,Institute for Theoretical Biology, Department of Biology, Humboldt-Universität zu Berlin, Berlin , Germany.,Department of Biology, University of Maryland , College Park, Maryland
| | - Catherine E Carr
- Department of Biology, University of Maryland , College Park, Maryland
| | - Richard Kempter
- Bernstein Center for Computational Neuroscience , Berlin , Germany.,Institute for Theoretical Biology, Department of Biology, Humboldt-Universität zu Berlin, Berlin , Germany.,Einstein Center for Neurosciences , Berlin , Germany
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Kuokkanen PT, Ashida G, Kraemer A, McColgan T, Funabiki K, Wagner H, Köppl C, Carr CE, Kempter R. Contribution of action potentials to the extracellular field potential in the nucleus laminaris of barn owl. J Neurophysiol 2017; 119:1422-1436. [PMID: 29357463 DOI: 10.1152/jn.00175.2017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Extracellular field potentials (EFP) are widely used to evaluate in vivo neural activity, but identification of multiple sources and their relative contributions is often ambiguous, making the interpretation of the EFP difficult. We have therefore analyzed a model EFP from a simple brainstem circuit with separable pre- and postsynaptic components to determine whether we could isolate its sources. Our previous papers had shown that the barn owl neurophonic largely originates with spikes from input axons and synapses that terminate on the neurons in the nucleus laminaris (NL) (Kuokkanen PT, Wagner H, Ashida G, Carr CE, Kempter R. J Neurophysiol 104: 2274-2290, 2010; Kuokkanen PT, Ashida G, Carr CE, Wagner H, Kempter R. J Neurophysiol 110: 117-130, 2013; McColgan T, Liu J, Kuokkanen PT, Carr CE, Wagner H, Kempter R. eLife 6: e26106, 2017). To determine how much the postsynaptic NL neurons contributed to the neurophonic, we recorded EFP responses in NL in vivo. Power spectral analyses showed that a small spectral component of the evoked response, between 200 and 700 Hz, could be attributed to the NL neurons' spikes, while nucleus magnocellularis (NM) spikes dominate the EFP at frequencies ≳1 kHz. Thus, spikes of NL neurons and NM axons contribute to the EFP in NL in distinct frequency bands. We conclude that if the spectral components of source types are different and if their activities can be selectively modulated, the identification of EFP sources is possible. NEW & NOTEWORTHY Extracellular field potentials (EFPs) generate clinically important signals, but their sources are incompletely understood. As a model, we have analyzed the auditory neurophonic in the barn owl's nucleus laminaris. There the EFP originates predominantly from spiking in the afferent axons, with spectral power ≳1 kHz, while postsynaptic laminaris neurons contribute little. In conclusion, the identification of EFP sources is possible if they have different spectral components and if their activities can be modulated selectively.
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Affiliation(s)
- Paula T Kuokkanen
- Institute for Theoretical Biology, Department of Biology, Humboldt-Universität zu Berlin, Berlin, Germany.,Department of Biology, University of Maryland , College Park, Maryland
| | - Go Ashida
- Cluster of Excellence "Hearing4all," Research Center Neurosensory Science, and Department of Neuroscience, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg , Oldenburg , Germany
| | - Anna Kraemer
- Department of Biology, University of Maryland , College Park, Maryland
| | - Thomas McColgan
- Institute for Theoretical Biology, Department of Biology, Humboldt-Universität zu Berlin, Berlin, Germany.,Bernstein Center for Computational Neuroscience, Berlin, Germany
| | - Kazuo Funabiki
- Institute of Biomedical Research and Innovation , Kobe , Japan
| | - Hermann Wagner
- Institute for Biology II, Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen, Aachen , Germany
| | - Christine Köppl
- Cluster of Excellence "Hearing4all," Research Center Neurosensory Science, and Department of Neuroscience, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg , Oldenburg , Germany
| | - Catherine E Carr
- Department of Biology, University of Maryland , College Park, Maryland
| | - Richard Kempter
- Institute for Theoretical Biology, Department of Biology, Humboldt-Universität zu Berlin, Berlin, Germany.,Bernstein Center for Computational Neuroscience, Berlin, Germany.,Einstein Center for Neurosciences, Berlin, Germany
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McColgan T, Liu J, Kuokkanen PT, Carr CE, Wagner H, Kempter R. Dipolar extracellular potentials generated by axonal projections. eLife 2017; 6:26106. [PMID: 28871959 PMCID: PMC5617635 DOI: 10.7554/elife.26106] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 09/01/2017] [Indexed: 01/27/2023] Open
Abstract
Extracellular field potentials (EFPs) are an important source of information in neuroscience, but their physiological basis is in many cases still a matter of debate. Axonal sources are typically discounted in modeling and data analysis because their contributions are assumed to be negligible. Here, we established experimentally and theoretically that contributions of axons to EFPs can be significant. Modeling action potentials propagating along axons, we showed that EFPs were prominent in the presence of terminal zones where axons branch and terminate in close succession, as found in many brain regions. Our models predicted a dipolar far field and a polarity reversal at the center of the terminal zone. We confirmed these predictions using EFPs from the barn owl auditory brainstem where we recorded in nucleus laminaris using a multielectrode array. These results demonstrate that axonal terminal zones can produce EFPs with considerable amplitude and spatial reach.
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Affiliation(s)
- Thomas McColgan
- Department for Biology, Institute for Theoretical BiologyHumboldt-Universität zu BerlinBerlinGermany
| | - Ji Liu
- Department of BiologyUniversity of MarylandCollege ParkUnited States
| | - Paula Tuulia Kuokkanen
- Department for Biology, Institute for Theoretical BiologyHumboldt-Universität zu BerlinBerlinGermany,Bernstein Center for Computational NeuroscienceBerlinGermany
| | | | | | - Richard Kempter
- Department for Biology, Institute for Theoretical BiologyHumboldt-Universität zu BerlinBerlinGermany,Bernstein Center for Computational NeuroscienceBerlinGermany,Einstein Center for NeurosciencesBerlinGermany
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The Role of Conduction Delay in Creating Sensitivity to Interaural Time Differences. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016. [PMID: 27080659 DOI: 10.1007/978-3-319-25474-6_20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register]
Abstract
Axons from the nucleus magnocellularis (NM) and their targets in nucleus laminaris (NL) form the circuit responsible for encoding interaural time difference (ITD). In barn owls, NL receives bilateral inputs from NM, such that axons from the ipsilateral NM enter NL dorsally, while contralateral axons enter from the ventral side. These afferents act as delay lines to create maps of ITD in NL. Since delay-line inputs are characterized by a precise latency to auditory stimulation, but the postsynaptic coincidence detectors respond to ongoing phase difference, we asked whether the latencies of a local group of axons were identical, or varied by multiples of the inverse of the frequency they respond to, i.e., to multiples of 2π phase. Intracellular recordings from NM axons were used to measure delay-line latencies in NL. Systematic shifts in conduction delay within NL accounted for the maps of ITD, but recorded latencies of individual inputs at nearby locations could vary by 2π or 4π. Therefore microsecond precision is achieved through sensitivity to phase delays, rather than absolute latencies. We propose that the auditory system "coarsely" matches ipsilateral and contralateral latencies using physical delay lines, so that inputs arrive at NL at about the same time, and then "finely" matches latency modulo 2π to achieve microsecond ITD precision.
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The Binaural Interaction Component in Barn Owl (Tyto alba) Presents few Differences to Mammalian Data. J Assoc Res Otolaryngol 2016; 17:577-589. [PMID: 27562803 DOI: 10.1007/s10162-016-0583-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 08/15/2016] [Indexed: 01/21/2023] Open
Abstract
The auditory brainstem response (ABR) is an evoked potential that reflects the responses to sound by brainstem neural centers. The binaural interaction component (BIC) is obtained by subtracting the sum of the monaural ABR responses from the binaural response. Its latency and amplitude change in response to variations in binaural cues. The BIC is thus thought to reflect the activity of binaural nuclei and is used to non-invasively test binaural processing. However, any conclusions are limited by a lack of knowledge of the relevant processes at the level of individual neurons. The aim of this study was to characterize the ABR and BIC in the barn owl, an animal where the ITD-processing neural circuits are known in great detail. We recorded ABR responses to chirps and to 1 and 4 kHz tones from anesthetized barn owls. General characteristics of the barn owl ABR were similar to those observed in other bird species. The most prominent peak of the BIC was associated with nucleus laminaris and is thus likely to reflect the known processes of ITD computation in this nucleus. However, the properties of the BIC were very similar to previously published mammalian data and did not reveal any specific diagnostic features. For example, the polarity of the BIC was negative, which indicates a smaller response to binaural stimulation than predicted by the sum of monaural responses. This is contrary to previous predictions for an excitatory-excitatory system such as nucleus laminaris. Similarly, the change in BIC latency with varying ITD was not distinguishable from mammalian data. Contrary to previous predictions, this behavior appears unrelated to the known underlying neural delay-line circuitry. In conclusion, the generation of the BIC is currently inadequately understood and common assumptions about the BIC need to be reconsidered when interpreting such measurements.
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Carr CE, Christensen-Dalsgaard J. Sound Localization Strategies in Three Predators. BRAIN, BEHAVIOR AND EVOLUTION 2015; 86:17-27. [PMID: 26398572 DOI: 10.1159/000435946] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
In this paper, we compare some of the neural strategies for sound localization and encoding interaural time differences (ITDs) in three predatory species of Reptilia, alligators, barn owls and geckos. Birds and crocodilians are sister groups among the extant archosaurs, while geckos are lepidosaurs. Despite the similar organization of their auditory systems, archosaurs and lizards use different strategies for encoding the ITDs that underlie localization of sound in azimuth. Barn owls encode ITD information using a place map, which is composed of neurons serving as labeled lines tuned for preferred spatial locations, while geckos may use a meter strategy or population code composed of broadly sensitive neurons that represent ITD via changes in the firing rate.
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Affiliation(s)
- Catherine E Carr
- Department of Biology, University of Maryland Center for the Comparative and Evolutionary Biology of Hearing, College Park, Md., USA
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Carr CE, Shah S, McColgan T, Ashida G, Kuokkanen PT, Brill S, Kempter R, Wagner H. Maps of interaural delay in the owl's nucleus laminaris. J Neurophysiol 2015. [PMID: 26224776 DOI: 10.1152/jn.00644.2015] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Axons from the nucleus magnocellularis form a presynaptic map of interaural time differences (ITDs) in the nucleus laminaris (NL). These inputs generate a field potential that varies systematically with recording position and can be used to measure the map of ITDs. In the barn owl, the representation of best ITD shifts with mediolateral position in NL, so as to form continuous, smoothly overlapping maps of ITD with iso-ITD contours that are not parallel to the NL border. Frontal space (0°) is, however, represented throughout and thus overrepresented with respect to the periphery. Measurements of presynaptic conduction delay, combined with a model of delay line conduction velocity, reveal that conduction delays can account for the mediolateral shifts in the map of ITD.
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Affiliation(s)
- Catherine E Carr
- Department of Biology, University of Maryland, College Park, Maryland;
| | - Sahil Shah
- Department of Biology, University of Maryland, College Park, Maryland
| | - Thomas McColgan
- Institute for Biology II, RWTH Aachen, Aachen, Germany; and Institute for Theoretical Biology, Department of Biology, Humboldt-Universität zu Berlin, and Bernstein Center for Computational Neuroscience, Berlin, Germany
| | - Go Ashida
- Department of Biology, University of Maryland, College Park, Maryland
| | - Paula T Kuokkanen
- Institute for Theoretical Biology, Department of Biology, Humboldt-Universität zu Berlin, and Bernstein Center for Computational Neuroscience, Berlin, Germany
| | - Sandra Brill
- Institute for Biology II, RWTH Aachen, Aachen, Germany; and
| | - Richard Kempter
- Institute for Theoretical Biology, Department of Biology, Humboldt-Universität zu Berlin, and Bernstein Center for Computational Neuroscience, Berlin, Germany
| | - Hermann Wagner
- Institute for Biology II, RWTH Aachen, Aachen, Germany; and
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Leibold C, Grothe B. Sound localization with microsecond precision in mammals: what is it we do not understand? ACTA ACUST UNITED AC 2015. [DOI: 10.1007/s13295-015-0001-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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