Population-Wide Bias of Surround Suppression in Auditory Spatial Receptive Fields of the Owl's Midbrain

Population-Wide Bias of Surround Suppression in Auditory Spatial Receptive Fields of the Owl's Midbrain

Wang Y Y; Shanbhag S J; Fischer B J; Pena J L

Journal of Neuroscience

2012

2012-08

The physical arrangement of receptive fields (RFs) within neural structures is important for local computations. Nonuniform distribution of tuning within populations of neurons can influence emergent tuning properties, causing bias in local processing. This issue was studied in the auditory system of barn owls. The owl's external nucleus of the inferior colliculus (ICx) contains a map of auditory space in which the frontal region is overrepresented. We measured spatiotemporal RFs of ICx neurons using spatial white noise. We found a population-wide bias in surround suppression such that suppression from frontal space was stronger. This asymmetry increased with laterality in spatial tuning. The bias could be explained by a model of lateral inhibition based on the overrepresentation of frontal space observed in ICx. The model predicted trends in surround suppression across ICx that matched the data. Thus, the uneven distribution of spatial tuning within the map could explain the topography of time-dependent tuning properties. This mechanism may have significant implications for the analysis of natural scenes by sensory systems.

barn owl; colliculus; difference; inferior; interaural time; macaque v1 neurons; motion-direction sensitivity; Neurosciences & Neurology; optic tectum; rat somatosensory cortex; superior colliculus; visual cortex; white-noise analysis

Journal Article

Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).

10470-10478

31

32