140 likes | 435 Views
Adaptive Plasticity in Barn Owl Tectum. Bartlett D. Moore IV :: DeBello Lab, Winter 2003. rostral. caudal. Barn owl. Midbrain Sound Localization Pathway. Optic tectum (OT). -20. Retinotopic visual input. Inferior colliculus (IC). 0. -20. 0. -20. 0. 20. 20. 20. 40. 40. 60.
E N D
Adaptive Plasticity in Barn Owl Tectum Bartlett D. Moore IV :: DeBello Lab, Winter 2003
rostral caudal Barn owl Midbrain Sound Localization Pathway Optic tectum (OT) -20 Retinotopic visual input Inferior colliculus (IC) 0 -20 0 -20 0 20 20 20 40 40 60 40 60 60 Ascending Interaural Timing Difference (ITD) information
Adaptive Plasticity of Auditory Tuning normal adaptive Normalized Response -16° -8° 0 ° +8° +16 ° Interaural Time Difference (ITD)
Question: • Adult owls do not adapt to large prismatic displacement. • However, adult owls can adapt to small prismatic displacements. Perhaps the amount of adult plasticity depends on quality of learning environment. • Will adult owls adapt to large prismatic displacements when provided live mice daily?
Methods 16 Speakers • Auditory spatial receptive field mapping from free field sound stimulation from 16 speaker locations, each 4° apart. • Visual receptive field mapping by projecting hand held stimuli onto tangent screen 64° owl
Sound Equalization Speaker 1 ~~~~~~~~~ microphone Speaker 2 ~~~~~~~~~ microphone Speaker 3 ~~~~~~~~~ microphone
Deep Tectum Responses Raster plot Speaker Location Right 24° Center (0°) Left 24° time (s) Stimulus duration
Superficial Tectum Raster and PSTH Speaker 16 Speaker locations Speaker 8 Speaker 1 time (ms)
Spatial tuning curve Raw firing rates VRF Left 28° Center (0°) Right 32°
Conclusions • Free field speaker array in combination with visual tangent screen is an excellent technique for measuring auditory-visual receptive field alignment. • No evidence of significant adaptive shift in the adult studied after 22 days of prism experience in aviary with live mice.
Thanks to: Dr. Will DeBello Odell ‘Austin’ Collins & the Birds