Stimulus-specific adaptation in the inferior colliculus: The role of excitatory, inhibitory and modulatory inputs

Context-specific adaptation (Shelhamer M, Clendaniel R. Neurosci Lett 332: 200–204, 2002) explains that reflexive responses can be maintained with different “calibrations” for different situations (contexts). Which context cues are crucial and how they combine to evoke context-specific adaptation is not fully understood. Gaze stabilization in birds is a nice model with which to tackle that question. Previous data showed that when pigeons ( Columba livia) were hung in a harness and subjected to a frontal airstream provoking a flying posture (“flying condition”), the working range of the optokinetic head response [optocollic reflex (OCR)] extended toward higher velocities compared with the “resting condition.” The present study was aimed at identifying which context cues are instrumental in recalibrating the OCR. We investigated that question by using vibrating stimuli delivered during the OCR provoked by rotating the visual surroundings at different velocities. The OCR gain increase and the boost of the fast phase velocity observed during the “flying condition” were mimicked by body vibration. On the other hand, the newly emerged relationship between the fast-phase and slow-phase velocities in the “flying condition” was mimicked by head vibration. Spinal cord lesion at the lumbosacral level decreased the effects of body vibration, whereas lesions of the lumbosacral apparatus had no effect. Our data suggest a major role of muscular proprioception in the context-specific adaptation of the stabilizing behavior, while the vestibular system could contribute to the context-specific adaptation of the orienting behavior. Participation of an efferent copy of the motor command driving the flight cannot be excluded.

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Sensitivity of rat inferior colliculus neurons to frequency distributions

Journal of Neurophysiology ◽

10.1152/jn.00555.2015 ◽

2015 ◽

Vol 114 (5) ◽

pp. 2941-2954 ◽

Cited By ~ 6

Author(s):

Björn Herrmann ◽

Aravindakshan Parthasarathy ◽

Emily X. Han ◽

Jonas Obleser ◽

Edward L. Bartlett

Keyword(s):

Inferior Colliculus ◽

Field Potentials ◽

Spectral Change ◽

Relative Probability ◽

Frequency Distributions ◽

Specific Adaptation ◽

Spectral Changes ◽

Neural Spiking ◽

Different Response ◽

Neural Gain

Stimulus-specific adaptation refers to a neural response reduction to a repeated stimulus that does not generalize to other stimuli. However, stimulus-specific adaptation appears to be influenced by additional factors. For example, the statistical distribution of tone frequencies has recently been shown to dynamically alter stimulus-specific adaptation in human auditory cortex. The present study investigated whether statistical stimulus distributions also affect stimulus-specific adaptation at an earlier stage of the auditory hierarchy. Neural spiking activity and local field potentials were recorded from inferior colliculus neurons of rats while tones were presented in oddball sequences that formed two different statistical contexts. Each sequence consisted of a repeatedly presented tone (standard) and three rare deviants of different magnitudes (small, moderate, large spectral change). The critical manipulation was the relative probability with which large spectral changes occurred. In one context the probability was high (relative to all deviants), while it was low in the other context. We observed larger responses for deviants compared with standards, confirming previous reports of increased response adaptation for frequently presented tones. Importantly, the statistical context in which tones were presented strongly modulated stimulus-specific adaptation. Physically and probabilistically identical stimuli (moderate deviants) in the two statistical contexts elicited different response magnitudes consistent with neural gain changes and thus neural sensitivity adjustments induced by the spectral range of a stimulus distribution. The data show that already at the level of the inferior colliculus stimulus-specific adaptation is dynamically altered by the statistical context in which stimuli occur.

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Angular vestibuloocular reflex responses in Otop1 mice. I. Otolith sensor input is essential for gravity context-specific adaptation

Journal of Neurophysiology ◽

10.1152/jn.00811.2018 ◽

2019 ◽

Vol 121 (6) ◽

pp. 2291-2299 ◽

Cited By ~ 5

Author(s):

Serajul I. Khan ◽

Charles C. Della Santina ◽

Americo A. Migliaccio

Keyword(s):

Semicircular Canals ◽

Vertical Axis ◽

Neural Circuitry ◽

Vestibuloocular Reflex ◽

Training Context ◽

Specific Adaptation ◽

Axis Parallel ◽

Vor Adaptation ◽

Context Specific

The role of the otoliths in mammals in the angular vestibuloocular reflex (VOR) has been difficult to determine because there is no surgical technique that can reliably ablate them without damaging the semicircular canals. The Otopetrin1 (Otop1) mouse lacks functioning otoliths because of failure to develop otoconia but seems to have otherwise normal peripheral anatomy and neural circuitry. By using these animals we sought to determine the role of the otoliths in angular VOR baseline function and adaptation. In six Otop1 mice and six control littermates we measured baseline ocular countertilt about the three primary axes in head coordinates; baseline horizontal (rotation about an Earth-vertical axis parallel to the dorsal-ventral axis) and vertical (rotation about an Earth-vertical axis parallel to the interaural axis) sinusoidal (0.2–10 Hz, 20–100°/s) VOR gain (= eye/head velocity); and the horizontal and vertical VOR after gain-increase (1.5×) and gain-decrease (0.5×) adaptation training. Countertilt responses were significantly reduced in Otop1 mice. Baseline horizontal and vertical VOR gains were similar between mouse types, and so was horizontal VOR adaptation. For control mice, vertical VOR adaptation was evident when the testing context, left ear down (LED) or right ear down (RED), was the same as the training context (LED or RED). For Otop1 mice, VOR adaptation was evident regardless of context. Our results suggest that the otolith translational signal does not contribute to the baseline angular VOR, probably because the mouse VOR is highly compensatory, and does not alter the magnitude of adaptation. However, we show that the otoliths are important for gravity context-specific angular VOR adaptation. NEW & NOTEWORTHY This is the first study examining the role of the otoliths (defined here as the utricle and saccule) in adaptation of the angular vestibuloocular reflex (VOR) in an animal model in which the otoliths are reliably inactivated and the semicircular canals preserved. We show that they do not contribute to adaptation of the normal angular VOR. However, the otoliths provide the main cue for gravity context-specific VOR adaptation.

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Role of 5-HT1A and 5-HT2 receptors in the aversion induced by electrical stimulation of inferior colliculus

Pharmacology Biochemistry and Behavior ◽

10.1016/0091-3057(94)00387-x ◽

1995 ◽

Vol 51 (2-3) ◽

pp. 317-321 ◽

Cited By ~ 25

Author(s):

L.L. Melo ◽

M.L. Brandão

Keyword(s):

Electrical Stimulation ◽

Inferior Colliculus ◽

Stimulation Of

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Role of frequency band integration in sharpening frequency tunings of the inferior colliculus neurons in the big brown bat, Eptesicus fuscus

Chinese Science Bulletin ◽

10.1360/04wc0018 ◽

2004 ◽

Vol 49 (10) ◽

pp. 1026 ◽

Cited By ~ 1

Author(s):

Feijian WU

Keyword(s):

Inferior Colliculus ◽

Frequency Band ◽

Eptesicus Fuscus ◽

Big Brown Bat

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Wakefulness-promoting role of the inferior colliculus

Behavioural Brain Research ◽

10.1016/j.bbr.2013.07.049 ◽

2013 ◽

Vol 256 ◽

pp. 82-94 ◽

Cited By ~ 4

Author(s):

Guillermo Cabrera ◽

Matías Cavelli ◽

Carolina Lopez ◽

Zulma Rodriguez-Servetti ◽

Giancarlo Vanini ◽

...

Keyword(s):

Inferior Colliculus

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Genotype×environment interactions and some considerations of their implications for wheat breeding in Australia This review is one of a series commissioned by the Advisory Committee of the Journal.

Australian Journal of Agricultural Research ◽

10.1071/a97035 ◽

1998 ◽

Vol 49 (2) ◽

pp. 153 ◽

Cited By ~ 105

Author(s):

K. E. Basford ◽

M. Cooper

Keyword(s):

Genetic Material ◽

Wheat Breeding ◽

Breeding Programs ◽

Specific Adaptation ◽

New Concepts ◽

Statistical Studies ◽

Definition Of ◽

Level Of Understanding ◽

The Impact

Genotype×environment (G×E) interactions complicate selection forbroad adaptation, while their nature and causes need to be understood toutilise and exploit them in selection for specific adaptation. This invitedreview combines an assessment of the literature with the experience we havegained from involvement in wheat breeding and associated research programs toassess (1) the implications of G×E interactions for wheat breeding inAustralia, (2) the impact that research into G E interactions has had onbreeding strategy, and (3) the evidence for impact from this research efforton genetic improvement of crop adaptation. The role of analytical methodologyin this process is considered and some important issues are discussed.There are sufficient examples drawn from wheat breeding in Australia tosuggest that progress in dealing with G×E interactions can be made andseveral of these are presented. They show that impact in plant breedingfollows from achieving an appropriate level of understanding of theenvironmental and genetic factors causing the interactions as well as anassessment of their importance in the target genotype-environment system. Anaccurate definition of the environmental factor(s) contributing to theG×E interactions has been particularly important in determining therelevance of observed differences in plant adaptation to the target populationof environments. From the combination of biological and statistical studies, amore comprehensive understanding of G×E interactions has emerged andcontributed to new concepts and procedures for dealing with them.Distinguishing between what are repeatable and non-repeatable interactions isa key step. Genuine cases of positive specific adaptation observed inmulti-environment trials (METs) can be exploited by appropriately targetedselection strategies, while non-repeatable interactions are accommodated byselection for broad adaptation.The investigation of G×E interactions for grain yield of wheat inAustralia has matured to the point where an understanding of some of theircauses has enabled wheat breeders to exploit positive components of specificadaptation. The experience that has been gained in achieving these advancesindicates the importance of establishing a MET system that is relevant to thetarget population of environments of the breeding program. The investment ofadequate resources into effective design, conduct, analysis, andinterpretation of METs remains critical to continued progress from selectionin complex genotype-environment systems that present large G× Einteractions. Wheat breeders who understand their genetic material and thetarget population of environments can then use the generated information baseto achieve impact from their breeding programs.

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Role of GABAergic Inhibition in the Coding of Interaural Time Differences of Low-Frequency Sounds in the Inferior Colliculus

Journal of Neurophysiology ◽

10.1152/jn.00956.2004 ◽

2005 ◽

Vol 93 (6) ◽

pp. 3390-3400 ◽

Cited By ~ 17

Author(s):

W. R. D’Angelo ◽

S. J. Sterbing ◽

E.-M. Ostapoff ◽

S. Kuwada

Keyword(s):

Inferior Colliculus ◽

Signal To Noise Ratio ◽

Interaural Time Difference ◽

Low Frequency ◽

Gabaergic Inhibition ◽

Interaural Time Differences ◽

Gaba Antagonists ◽

Inhibitory Transmitter ◽

Almost All

A major cue for the localization of sound in space is the interaural time difference (ITD). We examined the role of inhibition in the shaping of ITD responses in the inferior colliculus (IC) by iontophoretically ejecting γ-aminobutyric acid (GABA) antagonists and GABA itself using a multibarrel pipette. The GABA antagonists block inhibition, whereas the applied GABA provides a constant level of inhibition. The effects on ITD responses were evaluated before, during and after the application of the drugs. If GABA-mediated inhibition is involved in shaping ITD tuning in IC neurons, then applying additional amounts of this inhibitory transmitter should alter ITD tuning. Indeed, for almost all neurons tested, applying GABA reduced the firing rate and consequently sharpened ITD tuning. Conversely, blocking GABA-mediated inhibition increased the activity of IC neurons, often reduced the signal-to-noise ratio and often broadened ITD tuning. Blocking GABA could also alter the shape of the ITD function and shift its peak suggesting that the role of inhibition is multifaceted. These effects indicate that GABAergic inhibition at the level of the IC is important for ITD coding.

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