Yoram Gutfreund, PhD
Associate Professor of Physiology
PhD, 1999 - Hebrew University, Israel
The barn owl: a model system for studying how the brain determines the source of sounds
The focus of research in my laboratory is how information about the location of a sound source is represented in the brain and how this representation is shaped by sensory experience. We study the central auditory system of the barn owl, as this animal possesses superb auditory localization capabilities. The acoustic basis for the owl's sound localization is similar to many other species including humans but, perhaps because they rely on sound localization for survival, the neural representation of auditory space is sharper than in any other species studied. This enables us to identify biological effects with high sensitivity and confidence and should allow resolution of basic questions in sensory physiology. One line of research is characterizing how the auditory pathways are shaped by experience. Young barn owls are raised in various acoustic environments (different levels and protocols of background noise) so that the effect of acoustic experience on their brain and on sound localization behavior can be studied. The process of recovery after restoring normal acoustic experience (removal of background noise) is also investigated. Our findings, especially relevant in a world that is getting noisier every day, are expected to advance understanding of how adult behavior is determined by early life sensory experience. A second line of research is to study the integration of visual and auditory information in the barn owl's brain. We aim to identify where and how visual and auditory signals interact in the brain. The effects of such physiological interactions on the behavior of the animal are also explored. This line of research may shed light on some of the basic questions related to how the brain processes and combines information from different sensual modalities.
Hazan Y, Yarin I, Kra Y, Wagner H, and Gutfreund Y. 2015. Visual-auditory integration for visual search: a behavioral study in barn owls. Frontiers in Integrative Neuroscience. 9, 11.
Wang, Y, Gutfreund Y, and Pena JL. 2014. Coding space-time stimulus dynamics in auditory brain maps. Frontiers in Physiology. 5, 135.
Pena JL and Gutfreund Y. 2014. New perspectives on the owl's map of auditory space. Current Opinion in Neurobiology 24, 55-62.
Dutta A and Gutfreund Y. 2014. Saliency mapping in the optic tectum and its relationship to habituation. Frontiers in Integrative Neuroscience 8, 1.
Netser S, Dutta A, and Gutfreund Y. 2013. Ongoing activity in the optic tectum is correlated on a trial-by-trial basis with the pupil dilation response. Journal of Neurophysiology. 111, 918-29.
Studying the impact of acoustic experience on the barn owl brain.
We have identified two brain areas that combine visual and auditory information: in the forebrain entopallium (E) and in the thalamic nucleus rotondus (nRt). The figure shows a nissl-stained coronal section through the forebrain and midbrain of the barn owl in which the traces of an iontophoretic injection of fluoro-gold in the E and the retrograde labeled cell bodies in nRt can be seen. The two graphs show responses of a neuron in the E to rare (green curves) versus frequent (blue curves) bimodal stimuli (stimuli which combine visual and auditory inputs).