Abstract

Plasticity of phonotaxis in Acheta domesticus was evaluated in 207 young (5-7 days) and 328 old (28 days) female crickets. Of those that responded (508), their phonotaxis was grouped into selective (80% of young and 34% of old) and unselective (66% of old and 20% of young) on the basis of their responses to syllable period (SP). Two additional subcategories were also found. Some females were selective to the longer syllable periods (18% young, 20% old) while others were selective to the shorter syllable periods (7% young and 12% old). The L3 prothoracic auditory interneuron exhibits a decrementing response to calling songs (a reduction in the spiking of L3 in response to the second and third syllables of the chirp compared to the spikes produced in response to the first syllable measured as percentage). L3s from 33 females were evaluated and exhibited plasticity in their responses to syllable period. L3’s responses were grouped into four categories based on their selectivity to SP, which parallel the categories observed in phonotaxis including those that were a) selective to a narrow range of SPs, b) selective to shorter syllable periods, c) selective to longer syllable periods and d) unselective. Unselective L3s were further divided: those with a low-decrementing responses and those with a high-decrementing response. Decrementing responses of L3 result from a SP-selective excitation and a SP-selective delayed inhibition that is appropriately timed to cause a decrementing response to the second and third syllables of the chirp. Both the excitation and the delayed inhibition of L3 exhibit plasticity and their combined effects result in the plastic SP-selective response of L3, and are often correlated (i.e. the most selective excitatory responses are often found in the same L3s that have the most selective delayed inhibitions and resulting in the greatest decrement). Application of picrotoxin does not eliminate the delayed inhibition, but illustrates that both the level of SP-selective excitation and SP-selective delayed inhibition is influenced by a C1-current-based inhibition. The combined data suggests that SP-selective phonotaxis and its plasticity are in part the result of complex SP-selective processing by the L3 auditory interneuron.

LLU Discipline

Biology

Department

Biology

School

Graduate School

First Advisor

Gordon Atkins

Second Advisor

Ronald Carter

Third Advisor

David Cowles

Fourth Advisor

William Hayes

Fifth Advisor

John Stout

Degree Name

Doctor of Philosophy (PhD)

Degree Level

Ph.D.

Year Degree Awarded

2005

Date (Title Page)

6-2005

Language

English

Library of Congress/MESH Subject Headings

Neuronal Plasticity; Gryllidae; Evoked Potentials, Auditory; Acoustic Stimulation.

Type

Dissertation

Page Count

xi; 98

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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