Forward masking in the medial nucleus of the trapezoid body of the rat
| Autor: | Albert S. Berrebi, Fei Gao |
|---|---|
| Rok vydání: | 2015 |
| Předmět: |
0301 basic medicine
Sound localization Inferior colliculus medicine.medical_specialty Histology Auditory scene analysis Action Potentials Audiology Stimulus (physiology) Auditory cortex behavioral disciplines and activities Article Cochlear nucleus Rats Sprague-Dawley 03 medical and health sciences 0302 clinical medicine medicine Animals Trapezoid body Trapezoid Body Neurons General Neuroscience Rats 030104 developmental biology Acoustic Stimulation Superior olivary complex Auditory Perception Female Anatomy Psychology Perceptual Masking psychological phenomena and processes 030217 neurology & neurosurgery |
| Zdroj: | Brain Structure and Function. 221:2303-2317 |
| ISSN: | 1863-2661 1863-2653 |
| Popis: | Perception of acoustic stimuli is modulated by the temporal and spectral relationship between sound components. Forward masking experiments show that the perception threshold for a probe tone is significantly impaired by a preceding masker stimulus. Forward masking has been systematically studied at the level of the auditory nerve, cochlear nucleus, inferior colliculus and auditory cortex, but not yet in the superior olivary complex. The medial nucleus of the trapezoid body (MNTB), a principal cell group of the superior olive, plays an essential role in sound location. The MNTB receives excitatory input from the contralateral cochlear nucleus via the calyces of Held and innervates the ipsilateral lateral and medial superior olives (LSO and MSO), as well as the superior paraolivary nucleus (SPON). Here, we performed single-unit extracellular recordings in the MNTB of rats. Using a forward-masking paradigm previously employed in studies of the inferior colliculus and auditory nerve, we determined response thresholds for a 20 ms characteristic frequency (CF) pure tone (the probe), and then presented it in conjunction with another tone (the masker) that was varied in intensity, duration, and frequency; we also systematically varied the masker-to-probe delay. Probe response thresholds increased and response magnitudes decreased when a masker was presented. The forward suppression effects were greater when masker level and masker duration were increased, when the masker frequency approached the MNTB unit’s characteristic frequency, and as the masker-to-probe delay was shortened. Probe threshold shifts showed an exponential decay as the masker-to-probe delay increased. |
| Databáze: | OpenAIRE |
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