The Use of Electrodes To Study The Response Of Neurons In The Auditory System of Live Chicks Mobeen Farooq Mentor: Professor Jos Luis Pea Albert Einstein College of Medicine of Yeshiva University Introduction What is the auditory system? The barn owl The current model of the auditory system M. Konishi Caltech FIG. 1. Sound localization pathways in the barn owl. Time (ITD) and intensity (ILD) information are processed in 2 parallel pathways that originate in a bifurcation of the auditory nerve (nVIII) and converge in the inferior colliculus (IC). The IC projects to the forebrain () and tectal (1) sound localization pathways. NM, cochlear nucleus magnocellularis; NA, cochlear nucleus angularis; NL, nucleus laminaris; LLDp, nucleus of the lateral lemniscus pars posterior; ICx, external nucleus of the inferior colliculus; OT, optic tectum; Ov, nucleus ovoidalis; AAr, auditory arcopallium. Prez ML et. al 2006 Why experiment with live chicks? No one has done recording in live chicks previously Preditor vs. Prey A chance for comparison Introduction Continued VS. cdb 2003 english-country-garden Chicken eggs Stereotaxic apparatus Motorized micromanipulator The egg-warming device Metal electrodes for recording the neurons Pair of custom earphones The use of a computer to analyze the response properties of the neurons Methods & Materials No results at the moment! Results Sensitivity of AAr units to ITD and ILD in a barn owl with the ICX lesioned bilaterally. A and B: examples of ITD tuning curves. C and D: examples of ILD tuning curves. Cohen et. al 1998 Cohen YE, Miller GL, and Knudsen EI. Forebrain pathway for auditory space processing in the barn owl. J Neurophysiol 79: , Knudsen EI and Konishi M. A neural map of auditory space in the owl. Science 200; , Prez ML, Pea JL. Comparison of midbrain and thalamic space- specific neurons in barn owls. J Neurophysiol 95: References Acknowledgements Professor Jos Luis Pea Mario, Lucia and Sharaad Dr. Sat Bhattacharya Harlem Children Society