THE STRUCTURE AND FUNCTION OF EIMERS ORGAN IN THE MOLE
Paul D. Marasco
Dissertation under the direction of Kenneth C. Catania
This study examines the structure and function of Eimers organ in the mole. Eimers organ is a complex, well organized, and densely innervated mechanosensory structure found on the nose of the mole. Eimers organs appear to allow the mole make rapid sensory discriminations of objects. Labeling with AM1-43, substance P, neurofilament 200 and DiI revealed innervation patterns indicating that mechanosensory and nociceptive function is segregated to separate afferents within Eimers organ. Transmission electron microscopy revealed that the central column of Eimers organ may mechanically transduce stimuli and the intraepidermal free nerve endings do not appear to be active within the outer layer of the skin. The peripheral free nerve endings were structurally distinct from their central column counterparts and they were unmyelinated. The receptors in Eimers organ were similar in morphology to those found in a range of other mammalian skin. Electrophysiological examination revealed that the receptive fields for receptors in Eimers organ were small and response properties were consistent with an SA-1 receptor class, an FA-2 class. A second rapidly adapting class was hypothesized to represent activity of the mechanosensory free nerve endings. Most receptors were directionally sensitive and highly phase locked. Some receptors responded best when stimulated at a velocity matching the velocity of the nose in during foraging. The results support the hypothesis that Eimer's organ is a mechanosensory structure that functions to detect small surface features and textures by encoding and integrating deflection information for multiple Eimer's organs during brief touches.
| Identifer | oai:union.ndltd.org:VANDERBILT/oai:VANDERBILTETD:etd-10302006-120106 |
| Date | 06 December 2006 |
| Creators | Marasco, Paul Douglas |
| Contributors | Kenneth C. Catania, Jon H. Kaas, David E. McCauley, Terry L. Page |
| Publisher | VANDERBILT |
| Source Sets | Vanderbilt University Theses |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.library.vanderbilt.edu/available/etd-10302006-120106/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to Vanderbilt University or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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