Liu, Annie
(2017)
Effect of early odorant exposure on the structure and output of the glomerular module.
Doctoral Dissertation, University of Pittsburgh.
(Unpublished)
Abstract
Early sensory experience has the capacity to dramatically shape the final anatomy and function of a sensory circuit. Both sensory deprivation and enrichment have major impacts on the development and maintenance of sensory circuit structure. We take advantage of the stereotyped structure of the olfactory system to investigate how early odorant experience changes the structure and output of the mouse olfactory bulb. The olfactory system lacks the stimulus-based topography seen in the visual or auditory sensory systems, a consequence of the high dimensionality of odorant stimuli. However, it possesses a highly stereotyped organization, making it an ideal model system in which to study the processing of sensory stimuli in a systematic and specific manner. Axons from olfactory sensory neurons that express the same odorant receptor converge into glomeruli, spherical structures in the olfactory bulb (OB). Glomeruli and their post-synaptic targets, including principal projection neurons, the mitral and tufted cells, form the basis of the glomerular module, which is the basic odor coding unit of the OB. In this dissertation, we leverage this specific structure to study how early odorant experience changes the composition of a glomerular module and impacts the odor-evoked activity of mitral cells. In Chapter 2, we use an in vivo dye labeling technique to examine how prenatal and early postnatal odorant exposure impacts the number of primary projection neurons connected to activated glomeruli. We find that significantly more mitral and tufted cells become associated with activated glomerular modules, suggesting that sensory input plays a major role in modulating OB circuit refinement in early development. In Chapter 3, we investigate how odor-evoked mitral cell activity across the dorsal OB is impacted following the same exposure paradigm used in Chapter 2. Using 2-photon calcium imaging of mitral cell somata, we find that early odorant exposure increases the number, amplitude, and reliability of excitatory odor-evoked mitral cell responses, potentially due to sensory enrichment during a developmental critical period. Together, these findings demonstrate that early odorant experience dramatically impacts OB anatomy and output, which may have significant implications on odor representation in the OB and olfactory perception. These changes may also influence olfactory-guided behavior, such as odor discrimination and preference.
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Details
| Item Type: |
University of Pittsburgh ETD
|
| Status: |
Unpublished |
| Creators/Authors: |
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| ETD Committee: |
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| Date: |
29 June 2017 |
| Date Type: |
Publication |
| Defense Date: |
30 May 2017 |
| Approval Date: |
29 June 2017 |
| Submission Date: |
7 June 2017 |
| Access Restriction: |
No restriction; Release the ETD for access worldwide immediately. |
| Number of Pages: |
158 |
| Institution: |
University of Pittsburgh |
| Schools and Programs: |
School of Medicine > Neurobiology |
| Degree: |
PhD - Doctor of Philosophy |
| Thesis Type: |
Doctoral Dissertation |
| Refereed: |
Yes |
| Uncontrolled Keywords: |
olfactory bulb, plasticity, olfaction |
| Date Deposited: |
29 Jun 2017 15:49 |
| Last Modified: |
29 Jun 2017 15:49 |
| URI: |
http://d-scholarship.pitt.edu/id/eprint/32409 |
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