Edward L. Bartlett

1. Edward L. Bartlett • Ph.D., University of Wisconsin • Auditory thalamus in vitro synaptic physiology and anatomy • Postdoctoral Research at Johns Hopkins University • Auditory cortex and thalamus neuronal recordings in vivo • Assistant Professor, Departments of Biological Sciences and Biomedical Engineering • Functional organization of auditory cortex and thalamus in vivo and in vitro Aud. Cortex MGB IC Adapted from Netter

2. Current Research Areas • Neural representation of sound features in auditory thalamus and cortex • Sound sequences • Neural coding of temporal modulation • Neural coding of sound frequency, level • Neuroanatomy • Calcium-binding proteins • Correlation with neurophysiology • Animal Models: • Marmoset monkey (at JHU) • Rodent (at Purdue) Aud. Cortex Perception, Decision, Action Aud. Thalamus IC SOC/LL CN AN Sound Cochlea sound feature extraction

3. Methodologies • Single-neuron extracellular recording • -awake animals • Sound and electrical stimulation • Neuroanatomy • Intracellular recording in brain slices • -synaptics, dynamic clamp • Modeling of neurons and circuits

4. Recent Results Neural representation of temporal modulation - synchronized vs non-synchronized - temporally vs spectrally specialized pathways Correlation with MGB subdivision 40 Hz click train Synchronized Temporal representation,MGV 250 Hz click train Non-Synchronized Rate representation, MGCD

5. Future Directions • Auditory responses in thalamus and cortex: normal and aged animals • Corticothalamic feedback modulation • Representation of complex sounds (two sources, sounds in noise, behaviorally relevant sounds) • Cellular mechanisms of in vivo responses Auditory cortex Auditory thalamus Adapted from Castro-Alamancos, 2004 Single neuron response Cooling probe