Cortical processing of sensory information plays a critical role in sensory discrimination, object recognition and memory. Cortical sensory processing has been shown to be highly dynamic, with past experience, current context and expectations shaping how the world is perceived on a moment by moment basis. Disorders of sensory processing constitute a major component of impairments induced by CNS disease and aging, as well as congenital disorders such as schizophrenia and autism. In the olfactory sensory (piriform) cortex diverse stimulus features are synthesized into perceptual wholes through afferent and intrinsic fiber convergence and plasticity, allowing familiar odor objects to be remembered. The intrinsic, association fiber system in priform cortex is extensive, and based on anatomical data and new physiological data supported by an R21 to the co-PI's, plays a role in shaping cortical ensemble activity in response to odorant stimuli. Thus, our data demonstrate that odorants evoke distributed unit ensemble activity throughout anterior piriform cortex (aPCX), with individual components of the ensemble contributing to multiple odorant representations. In the present proposal, which extends the R21-supported research, we propose to address three previously untested hypotheses regarding cortical ensemble function in olfaction using multi-electrode array and paired single-unit recording in anesthetized and awake rats.
Aim 1 will test the hypothesis that cell ensemble membership size and the probability of correlated activity in paired single-units will be greater in the posterior PCX (pPCX) than in aPCX due to the more extensive intrinsic excitatory association fiber system in pPCX.
Aim 2 will test the hypothesis that manipulations of the neuromodulators ACh and NE to PCX, which selectively affect intrinsic fiber synaptic efficacy, will modulate ensemble membership size, odorant specificity and probability of correlated activity in paired single-units. Finally, Aim 3 will test the hypothesis that behavioral state will modulate ensemble size, odorant specificity and probability of correlated activity in cell pairs, potentially via a cholinergic or noradrenergic mechanism. Together, these aims will begin to explore how cortical ensembles merge the myriad odorant features encoded by peripheral circuits into odorant objects, and how attention and arousal may modulate odor discrimination.

Public Health Relevance

Cortical processing of information plays a critical role in sensory perception, memory, movement and cognition. Thus, understanding how circuits within the cortex process information is important for understanding and treating disorders of information processing. This proposal takes advantage of a relatively simple cortical circuit (the piriform cortex) performing relatively complex information processing tasks (odor object discrimination) to explore how groups of neurons work together as an ensemble to interpret sensory input.

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
Research Project (R01)
Project #
7R01DC008982-03
Application #
8008967
Study Section
Somatosensory and Chemosensory Systems Study Section (SCS)
Program Officer
Davis, Barry
Project Start
2008-07-01
Project End
2013-06-30
Budget Start
2009-09-01
Budget End
2010-06-30
Support Year
3
Fiscal Year
2009
Total Cost
$174,558
Indirect Cost
Name
University of Texas-Dallas
Department
Type
Other Domestic Higher Education
DUNS #
800188161
City
Richardson
State
TX
Country
United States
Zip Code
75080
Pruitt, David T; Schmid, Ariel N; Kim, Lily J et al. (2016) Vagus Nerve Stimulation Delivered with Motor Training Enhances Recovery of Function after Traumatic Brain Injury. J Neurotrauma 33:871-9
Ware, Taylor; Simon, Dustin; Liu, Clive et al. (2014) Thiol-ene/acrylate substrates for softening intracortical electrodes. J Biomed Mater Res B Appl Biomater 102:1-11
Simon, Dustin; Ware, Taylor; Marcotte, Ryan et al. (2013) A comparison of polymer substrates for photolithographic processing of flexible bioelectronics. Biomed Microdevices 15:925-39
Ware, Taylor; Simon, Dustin; Hearon, Keith et al. (2012) Three-Dimensional Flexible Electronics Enabled by Shape Memory Polymer Substrates for Responsive Neural Interfaces. Macromol Mater Eng 297:1193-1202
Lovitz, A M; Sloan, A M; Rennaker, R L et al. (2012) Complex mixture discrimination and the role of contaminants. Chem Senses 37:533-40
Chapuis, Julie; Wilson, Donald A (2012) Bidirectional plasticity of cortical pattern recognition and behavioral sensory acuity. Nat Neurosci 15:155-61
Wilson, Donald A; Sullivan, Regina M (2011) Cortical processing of odor objects. Neuron 72:506-19
Chen, Chien-Fu F; Barnes, Dylan C; Wilson, Donald A (2011) Generalized vs. stimulus-specific learned fear differentially modifies stimulus encoding in primary sensory cortex of awake rats. J Neurophysiol 106:3136-44
Wilson, Donald A; Yan, Xiaodan (2010) Sleep-like states modulate functional connectivity in the rat olfactory system. J Neurophysiol 104:3231-9
Schroeder, Charles E; Wilson, Donald A; Radman, Thomas et al. (2010) Dynamics of Active Sensing and perceptual selection. Curr Opin Neurobiol 20:172-6

Showing the most recent 10 out of 13 publications