QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by BROWN, H. F. Search for Related Content PubMed PubMed Citation Articles by BROWN, H. F.

Journal of Experimental Biology 41,723-734 (1964)
Published by Company of Biologists 1964

Electrophysiological Investigations of the Heart of Squilla Mantis : III. The Mode of Action of Pericardial Organ Extract on the Heart

HILARY F. BROWN ¹

¹ Stazione Zoologica Naples, and University Laboratory of Physiology, Oxford

1. There was a seasonal variation in the strength of the effect which extracts of the pericardial organs of Squilla mantis exert on the animal's heart. The extract was most effective in the spring and summer.

2. An investigation was made of the way in which the pericardial organ extract acts at a cellular level to increase the amplitude and frequency of the heart beat.

3. The extract did not affect the rate of impulse firing within the ganglionic nerve trunk burst. It increased the ratio of the number of impulses per burst: burst interval.

4. It initiated burst firing in complete g.n.t.'s which had become quiescent, and in those which had previously given only one impulse in response to an applied stimulus.

5. The junction potentials recorded intracellularly from Squilla heart muscle increased in height on adding pericardial extract. Some of this increase resulted from facilitation of the junction potentials at the increased heart rate, but 10-20% of the increase was rate-independent.

6. These results suggest that the extract acts at a minimum of two primary sites within the heart.

This article has been cited by other articles:

				H. Ando and K. Kuwasawa Neuronal and neurohormonal control of the heart in the stomatopod crustacean, Squilla oratoria J. Exp. Biol., December 15, 2004; 207(26): 4663 - 4677. [Abstract] [Full Text] [PDF]

				D. M. Ross Preferential Settling of the Sea Anemone Stomphia coccinea on the Mussel Modiolus modiolus Science, April 23, 1965; 148(3669): 527 - 528. [Abstract] [PDF]