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Dr

Pressler, Richard T
http://rave.ohiolink.edu/etdc/view?acc_num=case1153765647

Abstract Details

2006, Doctor of Philosophy, Case Western Reserve University, Neurosciences.
MECHANISMS OF SYNAPTIC AND INTRINSIC MODULATION OF GRANULE CELLS IN THE RAT OLFACTORY BULB Abstract By Richard Todd Pressler Mitral cell activity during olfactory behavior varies with respect to spatial location in the olfactory bulb, and temporally evolves during olfaction (Kay and Laurent, 1999). The main inhibitory input onto mitral cells originates from granule cells, axonless interneurons in the olfactory bulb, which sculpt and pattern mitral cell output through dendrodendritic inhibitory synapses (Price and Powell, 1970b). This dendrodendritic microcircuit can mediate recurrent inhibition onto mitral cells (Jahr et al., 1980), as well as lateral inhibition between mitral cells (Isaacson and Strowbridge, 1998). Additionally, this microcircuit plays a large part in generating gamma-frequency oscillations in the olfactory bulb during olfactory behavior (Lagier et al., 2004). Little data exists on the modulatory inputs onto granule cells from other olfactory bulb interneurons and from brain regions outside of the olfactory bulb. Previous anatomical studies suggest that granule cells receive GABAergic inputs from other olfactory bulb interneurons (Price and Powell, 1970b). Additionally, granule cells receive significant cholinergic input from the horizontal limb of the diagonal band (Price, 1969). viii First, I defined the intrinsic electrophysiological properties and synaptic inputs of a class of olfactory bulb interneuron that was previously unstudied. This interneuron, termed the Blanes cell based on their morphological similarity to olfactory bulb interneurons discussed in a classic neuroanatomical investigation (Blanes, 1890), have interesting intrinsic properties. Suprathreshold current injections can generate large amplitude afterdepolarizations in these cells. Additionally, these cells can enter a persistent firing mode following transient stimuli that is reset by membrane potential hyperpolarization. The Blanes cell is GABAergic, and can provide persistent inhibitory inputs onto granule cells, which may modulate granule cell firing for minutes in duration. Next, I investigated the effect of cholinergic receptor activation in granule cells. Cholinergic input to the olfactory bulb, from the horizontal limb of the diagonal band, plays a large role in sensory discrimination (Doty et al., 1999, Linster et al., 2001) and olfactory perceptual learning (Wilson et al., 2004). Cholinergic receptor activation in granule cells reveals a large amplitude stimulus evoked afterdepolarization. This afterdepolarization enhances granule cell excitability as well as inhibition onto mitral cells. These two inputs onto granule cells have interesting functional consequences on granule cell firing and olfactory bulb output.
Ben Strowbridge (Advisor)
Biology, Neuroscience
olfactory bulb mitral granule Blanes cell persistent feed forward inhibition

Recommended Citations

Citations

  • Pressler, R. T. (2006). Dr [Doctoral dissertation, Case Western Reserve University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=case1153765647

    APA Style (7th edition)

  • Pressler, Richard. Dr. 2006. Case Western Reserve University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=case1153765647.

    MLA Style (8th edition)

  • Pressler, Richard. "Dr." Doctoral dissertation, Case Western Reserve University, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=case1153765647

    Chicago Manual of Style (17th edition)

case1153765647
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© 2006, all rights reserved.
This open access ETD is published by Case Western Reserve University School of Graduate Studies and OhioLINK.