1. The Use of Electrodes To Study The Response Of Neurons In The Auditory System of Live Chicks Mobeen Farooq Mentor: Professor José Luis Peña Albert Einstein College of Medicine of Yeshiva University

2. 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. © Pérez ML et. al 2006

3. 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

4. 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

6. 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

7. Cohen YE, Miller GL, and Knudsen EI. Forebrain pathway for auditory space processing in the barn owl. J Neurophysiol 79: 891-902, 1998. Knudsen EI and Konishi M. A neural map of auditory space in the owl. Science 200; 795-797, 1978. Pérez ML, Peña JL. Comparison of midbrain and thalamic space- specific neurons in barn owls. J Neurophysiol 95: 783-790. References

8. Acknowledgements Professor José Luis Peña Mario, Lucia and Sharaad Dr. Sat Bhattacharya Harlem Children Society