Experience-dependent plasticity in the inferior colliculus: a site for visual calibration of the neural representation of auditory space in the barn owl

摘要: The optic tectum (homolog of the superior colliculus) contains mutually aligned neural maps auditory and visual space. During development, organization map is guided by spatial information provided vision: barn owls raised wearing prismatic spectacles, which optically shift field in tectum, develop an that shifted approximately equivalent amount, such alignment between two preserved (Knudsen Brainard, 1991). In this study we investigated whether intrinsic to or it reflects plasticity at earlier stage pathway. Owls were spectacles displaced 23 degrees left right. This manipulation alters normal correspondence locations interaural time difference (ITD), primary cue for azimuth a sound source. with least 150 d prism experience, extracellular unit recordings used assess representations ITD anatomically physiologically defined sites prior stages pathway, external central nuclei inferior colliculus (ICx ICc). owls, values units responded most strongly (best ITDs) varied systematically azimuths receptive fields (VRFs). prism-reared best ITDs from toward produced sounds units' VRFs. ICx representation also was normal, amount direction could completely account measured tectum. At some ICx, tuning apparent within first 7-8 msec response; short latencies argues altered ascending not result descending activity higher centers. ICc, immediately precedes normal. results indicate instruction neurons level site where space synthesized.