Detection of Interaural Time Differences in the Alligator

Carr, Catherine E.; Soares, Daphne; Smolders, Jean W.T.; Simon, Jonathan Z.

doi:10.1523/jneurosci.6154-08.2009

Cited by 54 publications

(93 citation statements)

References 78 publications

(140 reference statements)

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“…This increases the variability of anatomical correlations with physiology (since the BF or the best ITD of a specific low-frequency neurophonic might slightly differ compared to a single unit at the same location) but does not principally invalidate neurophonic data. Indeed, as observed previously [Köppl and Carr, 2008;Carr et al, 2009], there were no significant differences in best ITD, best IPD, CD, or CP between the populations of single-unit, multiunit, and neurophonic recordings. Thus, all of the conclusions in this paper are consistent with the single-unit data, although they comprised a minority of the sample.…”

Section: Validity Of the Neurophonic As A Proxy For Nl Responsessupporting

confidence: 82%

In vivo Recordings from Low-Frequency Nucleus Laminaris in the Barn Owl

Palanca-Castan

Köppl²

2015

Brain Behav Evol

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Localization of sound sources relies on 2 main binaural cues: interaural time differences (ITD) and interaural level differences. ITD computing is first carried out in tonotopically organized areas of the brainstem nucleus laminaris (NL) in birds and the medial superior olive (MSO) in mammals. The specific way in which ITD are derived was long assumed to conform to a delay line model in which arrays of systematically arranged cells create a representation of auditory space, with different cells responding maximally to specific ITD. This model conforms in many details to the particular case of the high-frequency regions (above 3 kHz) in the barn owl NL. However, data from recent studies in mammals are not consistent with a delay line model. A new model has been suggested in which neurons are not topographically arranged with respect to ITD and coding occurs through assessment of the overall response of 2 large neuron populations - 1 in each brainstem hemisphere. Currently available data comprise mainly low-frequency (<1,500 Hz) recordings in the case of mammals and higher-frequency recordings in the case of birds. This makes it impossible to distinguish between group-related adaptations and frequency-related adaptations. Here we report the first comprehensive data set from low-frequency NL in the barn owl and compare it to data from other avian and mammalian studies. Our data are consistent with a delay line model, so differences between ITD processing systems are more likely to have originated through divergent evolution of different vertebrate groups.

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Section: Validity Of the Neurophonic As A Proxy For Nl Responsessupporting

confidence: 82%

In vivo Recordings from Low-Frequency Nucleus Laminaris in the Barn Owl

Palanca-Castan

Köppl²

2015

Brain Behav Evol

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“…There is strong evidence in birds and reptiles for the canonical Jeffress model (1948), in which a counter-current organization of ipsilateral and contralateral projections to the nucleus laminaris (NL) converts a temporal code into a place code through delay-line coincidence detection (Carr and Konishi 1990;Carr et al 2009;Funabiki et al 2011). By contrast, binaural projections to the mammalian medial superior olive (MSO) do not appear to include delay lines (McAlpine and Grothe 2003;Smith et al 1993).…”

Section: Discussionmentioning

confidence: 99%

“…In birds and reptiles, ITDs are analyzed through delay-line coincidence detection of binaural excitatory inputs (Carr and Konishi 1990;Carr et al 2009;Funabiki et al 2011). In mammals, ITD detection also relies on coincidence detection of binaural excitatory inputs, but the mechanistic basis for ITD tuning remains controversial and cannot be explained by axonal delay lines (Brand et al 2002;Grothe et al 2010;McAlpine and Grothe 2003;Roberts et al 2013;van der Heijden et al 2013).…”

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confidence: 99%

Detection of submillisecond spike timing differences based on delay-line anticoincidence detection

Lyons-Warren

Kohashi

Mennerick

et al. 2013

Journal of Neurophysiology

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Lyons-Warren AM, Kohashi T, Mennerick S, Carlson BA. Detection of submillisecond spike timing differences based on delayline anticoincidence detection. J Neurophysiol 110: 2295-2311. First published August 21, 2013 doi:10.1152/jn.00444.2013.-Detection of submillisecond interaural timing differences is the basis for sound localization in reptiles, birds, and mammals. Although comparative studies reveal that different neural circuits underlie this ability, they also highlight common solutions to an inherent challenge: processing information on timescales shorter than an action potential. Discrimination of small timing differences is also important for species recognition during communication among mormyrid electric fishes. These fishes generate a species-specific electric organ discharge (EOD) that is encoded into submillisecond-to-millisecond timing differences between receptors. Small, adendritic neurons (small cells) in the midbrain are thought to analyze EOD waveform by comparing these differences in spike timing, but direct recordings from small cells have been technically challenging. In the present study we use a fluorescent labeling technique to obtain visually guided extracellular recordings from individual small cell axons. We demonstrate that small cells receive 1-2 excitatory inputs from 1 or more receptive fields with latencies that vary by over 10 ms. This wide range of excitatory latencies is likely due to axonal delay lines, as suggested by a previous anatomic study. We also show that inhibition of small cells from a calyx synapse shapes stimulus responses in two ways: through tonic inhibition that reduces spontaneous activity and through precisely timed, stimulus-driven, feed-forward inhibition. Our results reveal a novel delay-line anticoincidence detection mechanism for processing submillisecond timing differences, in which excitatory delay lines and precisely timed inhibition convert a temporal code into a population code. temporal coding; electric fish; calyx; sound localization; interaural time difference TEMPORAL CODING, in which information is encoded into the precise timing of action potentials, is common in sensory systems ( VanRullen et al. 2005). In some cases, behavioral sensitivity can reach the submillisecond or even submicrosecond range, several orders of magnitude shorter than a typical action potential

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“…Moiseenkova et al, 2003;Carr et al, 2009). To avoid this potential complication, we documented directional sensitivity using a single horizontal axis (located at 10deg vertically above the pit organ) and a single azimuthal axis (located at 40deg in front of the pit organ).…”

Section: Stimulusmentioning

confidence: 99%

Directional sensitivity in the thermal response of the facial pit in western diamondback rattlesnakes (Crotalus atrox)

Kohl

Colayori

Westhoff

et al. 2012

Journal of Experimental Biology

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SUMMARYRecent work published in the accompanying paper used a combination of 3D morphological reconstruction to define optical spread functions and heat transfer physics to study how external heat energy would reach the sensory membrane within the facial pit of pitvipers. The results from all of the species examined indicated asymmetric directional sensitivity, e.g. the pit would preferentially respond to stimuli located below and behind the snake. The present study was intended as a test of these findings through a quantitative neurophysiological analysis of directional sensitivity in the facial pit of the western diamondback rattlesnake, Crotalus atrox. An infrared emitter was positioned through a coordinate system (with varying angular orientations and distances) and the response it evoked measured through neurophysiological recordings of a trigeminal nerve branch composed of the afferents from the sensory membrane of the facial pit. Significant differences were found in the strength of the membraneʼs neural response to a constant stimulus presented at different orientations (relative to the facial pit opening) and over different distances. The peak sensitivity (at 12deg above and 20deg in front of the facial pit opening) was in good agreement with the predicted directional sensitivities based on optical spread functions and 3D topography. These findings support the hypothesis that the topography, and functional performance, of the facial pit has undergone an adaptive radiation within the pit vipers, and that differences in the behavioral ecology of the pit vipers (i.e. terrestrial versus arboreal) are reflected within the facial pits.

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Detection of Interaural Time Differences in the Alligator

Cited by 54 publications

References 78 publications

In vivo Recordings from Low-Frequency Nucleus Laminaris in the Barn Owl

In vivo Recordings from Low-Frequency Nucleus Laminaris in the Barn Owl

Detection of submillisecond spike timing differences based on delay-line anticoincidence detection

Directional sensitivity in the thermal response of the facial pit in western diamondback rattlesnakes (Crotalus atrox)

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