Neural mechanisms of auditory perception and emotional learning


May 6, 2014 - 1:00pm
NW 243
About the Speaker
Maria Geffen (UPenn)

Hearing perception relies on our ability to tell apart the spectral content of different sounds, and to learn to use this difference to distinguish behaviorally relevant (such as dangerous and safe) sounds. A number of recent studies, conducted in both human patients and animal models, suggest an important role for AC in frequency discrimination and emotional auditory learning, challenging the “classical” view, which postulated that the auditory cortex was not important for frequency discrimination. Recently, we demonstrated that the auditory cortex regulates frequency discrimination acuity following emotional learning (Aizenberg and Geffen, Nature Neuroscience, 2013). However, the neuronal circuits that underlie this modulation remain unknown. In the auditory cortex, the excitatory neurons serve the dominant function in transmitting information about the sensory world within and across brain areas, whereas inhibitory interneurons carry a range of modulatory functions, shaping the way information is represented and processed. We recently found that the most common class of interneurons, parvalbumin-positive (PVs), modulate frequency selectivity of excitatory neurons in AC, and regulate frequency discrimination acuity and specificity of discriminative auditory emotional learning. We further found that PVs and another class of interneurons, somatostatin- positive interneurons, regulate adaptation in responses of AC neurons to frequent sounds, in a complementary manner. These results expand our understanding of how specific cortical circuits contribute to auditory perception in everyday acoustic environments.