George Maeda

Abstract

An isolated heart-abdominal ganglion preparation of this mollusc was developed and used to study the cardioregulatory function of the ganglion and nerves. The heart was perfused with artificial sea water through an atrial cannula and the gastro-esophageal artery was catheterized for blood pressure monitoring. The presence and cardioregulatory effects of axons in the nerves was investigated by electrical stimulation. Fine-tipped glass microelectrodes inserted into ganglionic neurons were used to determine the relationship between the neuronal and cardiac activities.

The principal results are listed below.

  1. Primarily inhibitory responses are obtained from both right and left connective stimulation, with some evidence for excitatory axons.
  2. The siphon nerve exerts a strong inhibitory influence on the heart, probably acting as part of a feedback pathway.
  3. Predominantly acceleratory responses are elicited from pericardial nerve stimulation (confirming work of Wright, 1960, and Carlson, 1905).
  4. A high frequency spike burst in L7 precedes bradycardia, a coincidental but not deterministic relationship obtained from one subject.
  5. Preliminary evidence indicates the presence of a nondeterministic inhibition of long duration in cell L10 associated with bradycardia.
  6. There is speculative evidence for inhibitory axons in the genital nerve.

Department

Physiology

School

Graduate School

First Advisor

Bernell E. Baldwin

Second Advisor

Kenneth A. Arendt

Third Advisor

Elwood S. McCluskey

Degree Name

Master of Science (MS)

Degree Level

M.S.

Year Degree Awarded

1971

Date (Title Page)

6-1971

Language

English

Library of Congress/MESH Subject Headings

Heart -- physiology; Aplysia -- physiology

Type

Thesis

Page Count

vii; 95

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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