UVM Theses and Dissertations
Format:
Online
Author:
Taylor-Burds, Carol
Dept./Program:
Biology
Year:
2010
Degree:
PhD
Abstract:
In olfaction, the olfactory sensory neuron (OSN) is the point where chemical environment activates an electrochemical signaling that will result in odor perception. The OSNs in the main olfactory epithelium are part of a four part olfactory system that provides chemical sensory information, and can alter behavior through odor recognition, pheromone detection, and memory retrieval.
Here we studied the canonical odor transduction patlrway, mediated by cAMP production and calcium influx, under conditions where mice were housed in either an odor-enriched, or standard animal housing environment. Very little is known about how odor exposure in the housing environment alters odor signaling in olfactory sensory neurons (OSNs). Using calcium imaging and perforated patch clamp recordings we examined the responses produced by activation ofthe odormediated cAMP signal transduction pathway. Our results showed that increased odor exposure corresponded to slower calcium recovery rates when the cAMP pathway was stimulated.
In addition to CS7BLj6 mice, we also tested mice without olfactory marker protein (OMP). OMP is a small cytosolic protein that is only expressed in mature OSNs. OMPhas been shown to alter odor responses, however its role(s) in OSNs is still unknown. Here we report that both C57BL/6 and OMP⁻/⁻OSNs had slower calcium transient recovery rates in mice from odor enriched housing giving a longer-lasting response. Aunique finding was that the OMP⁻/⁻OSNs from both odor-environments had shorter responsesthan their C57BL/6 odor matched counterpart. Using different stimuli to isolate the reasons for these differences, we found that odor-enrichment appeared to be altering events in the cilia, whereas OMP⁻/⁻OSNs had reduced responses to stimulation of adenylyl cyclase.
Higher order structures also playa role in olfactory detection and perception by fine-tuning the activity pattern in the olfactory bulb and directing attention to relevant odorants from descending cortical control. To study these aspects of olfactory function, behavioral methods are necessary to understand alteration in perceptionofodorants.Wemeasuredthedetection thresholdofCS7BL/6and CD1 mice to the odor geraniol and established that C57BL/6 and CDI mice are quite similar in their detection abilities. To detect odor perceptual differences where only subtle differences may be we also used an odor-masking task that proved to be sensitive to strain differences between CS7BL/6 and Balbjc mice. These studies help focus our testing procedures for olfactory impairmentand function for future work.
Here we studied the canonical odor transduction patlrway, mediated by cAMP production and calcium influx, under conditions where mice were housed in either an odor-enriched, or standard animal housing environment. Very little is known about how odor exposure in the housing environment alters odor signaling in olfactory sensory neurons (OSNs). Using calcium imaging and perforated patch clamp recordings we examined the responses produced by activation ofthe odormediated cAMP signal transduction pathway. Our results showed that increased odor exposure corresponded to slower calcium recovery rates when the cAMP pathway was stimulated.
In addition to CS7BLj6 mice, we also tested mice without olfactory marker protein (OMP). OMP is a small cytosolic protein that is only expressed in mature OSNs. OMPhas been shown to alter odor responses, however its role(s) in OSNs is still unknown. Here we report that both C57BL/6 and OMP⁻/⁻OSNs had slower calcium transient recovery rates in mice from odor enriched housing giving a longer-lasting response. Aunique finding was that the OMP⁻/⁻OSNs from both odor-environments had shorter responsesthan their C57BL/6 odor matched counterpart. Using different stimuli to isolate the reasons for these differences, we found that odor-enrichment appeared to be altering events in the cilia, whereas OMP⁻/⁻OSNs had reduced responses to stimulation of adenylyl cyclase.
Higher order structures also playa role in olfactory detection and perception by fine-tuning the activity pattern in the olfactory bulb and directing attention to relevant odorants from descending cortical control. To study these aspects of olfactory function, behavioral methods are necessary to understand alteration in perceptionofodorants.Wemeasuredthedetection thresholdofCS7BL/6and CD1 mice to the odor geraniol and established that C57BL/6 and CDI mice are quite similar in their detection abilities. To detect odor perceptual differences where only subtle differences may be we also used an odor-masking task that proved to be sensitive to strain differences between CS7BL/6 and Balbjc mice. These studies help focus our testing procedures for olfactory impairmentand function for future work.