Both the mammalian and avian auditory systems localize sound sources by computing the interaural time difference (ITD) with submillisecond accuracy. The neural circuits for this computation in birds consist of axonal delay lines and coincidence detector neurons. Here, we report the first in vivo intracellular recordings from coincidence detectors in the nucleus laminaris of barn owls. Binaural tonal stimuli induced sustained depolarizations (DC) and oscillating potentials whose waveforms reflected the stimulus. The amplitude of this sound analog potential (SAP) varied with ITD, whereas DC potentials did not. The amplitude of the SAP was correlated with firing rate in a linear fashion. Spike shape, synaptic noise, the amplitude of SAP, and responsiveness to current pulses differed between cells at different frequencies, suggesting an optimization strategy for sensing sound signals in neurons tuned to different frequencies.
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http://dx.doi.org/10.1523/JNEUROSCI.2127-11.2011 | DOI Listing |
Int J Pediatr Otorhinolaryngol
January 2025
Department of Physical Therapy, Speech-Language Pathology and Occupational Therapy, Medical School, University of São Paulo, São Paulo, 05360-160, Brazil.
Growing numbers of children and adults who are deaf are eligible to receive cochlear implants (CI), which provide access to everyday sound. CIs in both ears (bilateral CIs or BiCIs) are becoming standard of care in many countries. However, their effectiveness is limited because they do not adequately restore the acoustic cues essential for sound localization, particularly interaural time differences (ITDs) at low frequencies.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Department of Communication Science and Disorders, University of Pittsburgh, Pittsburgh, PA 15213.
Neuropsychologia
December 2024
Stockholm University, Department of Psychology, Sweden.
In the search for the neural correlates of auditory consciousness, a candidate has been found using electroencephalography: the auditory awareness negativity (AAN). Earlier studies have investigated the AAN in response to lateralized sound. With headphones, there is a clear lateralization of AAN when two auditory lateralization cues are combined: the interaural level difference (ILD) and interaural time difference (ITD).
View Article and Find Full Text PDFNeuroscience
December 2024
School of Psychological and Cognitive Sciences, Peking University, Beijing 100080, China.
Prepulse inhibition (PPI) refers to the phenomenon in which a weak sensory stimulus before a strong one significantly reduces the startle reflex caused by the strong stimulus. Perceptual spatial separation, a phenomenon where auditory cues from the prepulse and background noise are distinguished in space, has been shown to enhance PPI. This study aims to investigate the neural modulation mechanisms of PPI by the spatial separation between the prepulse stimulus and background noise, particularly in the deep superior colliculus (deepSC).
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