The School of Molecular and Cellular Biology at the University of Illinois at Urbana-Champaign

Our laboratory studies the mechanisms by which complex sounds, such as speech, are processed by the auditory system. We hypothesize that the auditory system generates internal models of the sensory world, and uses these models to extract meaning from complex sensory stimuli. One potential neuronal substrate for this generative model is the massive system of descending projections from the auditory cortex to virtually every level of the subcortical auditory system. These projections are critical for shaping the response properties of neurons in the auditory periphery, but very little is known about their functional organization.

We employ electrophysiological, novel optical and advanced anatomical approaches to study the projections from the auditory cortex to subcortical structures. One specific set of issues that we address concerns the role of different cortical subnetworks in complex sound processing. For example, neurons in both cortical layer 5 and cortical layer 6 project to subcortical structures, and the neurons in these layers have very different intrinsic, integrative and synaptic properties. Our work explores the different roles that these groups of neurons play in the processing of complex sound.

We also have a strong interest in studying the reorganization of such networks during neuronal disease. In particular, we are developing models of dementia and age-related auditory network dysfunction, and hope to use these models for the development of novel therapeutic approaches.

Representative Publications

Llano D.A. and A.S. Feng (2000) Computational models of temporal processing in the auditory thalamus. Biological Cybernetics. 83: 419-433.

Galazyuk A.V., Lin W., Llano D. and A.S. Feng. (2005) Leading inhibition and oscillation in time-domain processing in the auditory midbrain. Journal of Neurophysiology. Jul;94(1):314-26.

Llano D.A. and S.M. Sherman (2008) Evidence for non-reciprocal organization of the mouse auditory thalamocortical-corticothalamic projection systems. Journal of Comparative Neurology. 507:1209-1227.

Llano D.A., Theyel B.B., Mallik A., Sherman S.M. and N.P. Issa (2009) Rapid and sensitive mapping of long range connections in vitro using flavoprotein autofluorescence imaging combined with laser photostimulation. Journal of Neurophysiology. 101(6):3325-40

Llano D.A. and S.M. Sherman (2009) Differences in intrinsic properties and local network connectivity of identified layer 5 and layer 6 adult mouse auditory corticothalamic neurons support a dual corticothalamic projection hypothesis. Cerebral Cortex. Dec;19(12):2810-26.

Small S.L. and Llano D.A. (2009) Biological therapy for aphasia. Current Neurology and Neuroscience Reports. Nov;9(6):443-50.

Lu E., Llano D.A. and S. M. Sherman. (2009) Different distributions of calbindin and calretinin immunostaining across the medial and dorsal divisions of the mouse medial geniculate body. Hearing Research. Nov;257(1-2):16-23.

Theyel B.B., Llano D.A. and S. M. Sherman. (2010) Evidence for a cortico-thalamocortical pathway for cortical communication. Nature Neuroscience. 13(1):84-8.

Llano D.A. , Laforet, G. and V. Devanarayan (2011) Derivation of a new ADAS-cog composite using tree-based multivariate analysis: Prediction of conversion from mild cognitive impairment to Alzheimer's disease. Alzheimer’s Disease and Associated Disorders. Jan-Mar;25(1):73-84.

Theyel B.B., Llano D.A., Issa N., Mallik A. and S. M. Sherman. (2011) Laser photostimulation with flavoprotein autofluorescence imaging in vitro. Nature Protocols. Apr;6(4):502-8.

Llano D.A., Li J., Lenz R.A., Ellis T., Cassar S., Groebe D., Gopalakrishnan M. and Waring J.F. (2011) Evidence for disrupted CNS inflammatory dynamics in Alzheimer’s Disease. Alzheimer Dis Assoc Disord. Nov 15. [Epub ahead of print]

Yang S., Yang S., Cox C.L., Llano D.A., Feng A.S. (2012) Cell's intrinsic biophysical properties play a role in the systematic decrease in time-locking ability of central auditory neurons. Neuroscience. 2012 Apr 19;208:49-57.

Llano D.A., Simon A. and V. Devanarayan (2012) Evaluation of plasma proteomic data for Alzheimer's Disease state classification and for prediction of progression from mild cognitive impairment to Alzheimer Disease. Accepted, Alzheimer Disease and Associated Disorders

Llano D.A. (2012) Functional imaging of the thalamus in language. Accepted, Brain and Language.

Llano D.A., Caspary D. and J. Turner (2012) Diminished cortical inhibition in an aging mouse model of chronic tinnitus. Accepted, Journal of Neuroscience

Llano D.A. (2012) Voices below the surface:Is there a role for the thalamus in language? Accepted, Brain and Language.

Slater B.J., Willis A. and D.A. Llano (2012) Evidence for layer-specific differences in auditory corticocollicular neurons. Accepted. Neuroscience.