Abstract

Olfactory bulb efferents sweep caudally over the prepyriform cortex in a broad fiber sheet called the lateral olfactory tract (LOT). The LOT begins as a compact sheet of fibers in the olfactory peduncle and narrows to a bundle caudally. It is the primary axonal pathway between the olfactory bulb and the cortex. The shape and cross-sectional area of the LOT was measured from histologic sections. The cross-sectional area diminishes to about half from rostral to caudal measurements. An array of 58 electrodes spaced at intervals of 1 mm was constructed to conform to the curvilinear surface and geometry of the prepyriform cortex including the LOT. Action potentials were sampled sequentially through the array for various bulbar mitral cell locations below the surface and ringing the circumference of the bulb. The data were analyzed and displayed graphically to show potential amplitudes, latency, spatial and temporal dispersion, trajectory, velocity and other patterns of conducted activity over the tract. An amplitude peak could be identified in time and in a two-dimensional representation of the LOT. The amplitude peaks of the action potential were computed for the extent of the LOT for each experiment.

Three-dimensional potential maps were computed, plotted and photographed to visualize the sequence of LOT impulse propagation. The velocity decreased by 50% from the rostral to caudal extremities of the LOT.

Evidence is presented for a diffuse topographical relationship between olfactory bulb and the cortex. The temporal and spatial dispersion of the action potential gave support for the anatomical descriptions of fiber pathways and terminations within the prepyriform cortex.

LLU Discipline

Physiology

Department

Physiology

School

Graduate School

First Advisor

T. Joe Willey

Second Advisor

Ivan R. Neilsen

Third Advisor

Kenneth A. Arendt

Fourth Advisor

Donald D. Rafuse

Degree Name

Doctor of Philosophy (PhD)

Degree Level

Ph.D.

Year Degree Awarded

1980

Date (Title Page)

8-1980

Language

English

Library of Congress/MESH Subject Headings

Olfactory Bulb

Type

Thesis

Page Count

vi; 88

Digital Format

PDF

Digital Publisher

Loma Linda University Libraries

Usage Rights

This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.

Collection

Loma Linda University Electronic Theses and Dissertations

Collection Website

http://scholarsrepository.llu.edu/etd/

Repository

Loma Linda University. Del E. Webb Memorial Library. University Archives

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