spacer gif spacer gif spacer gif spacer gif spacer gif
QUICK SEARCH:   [advanced]


spacer gif
     Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents    

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by YEE, A.
Right arrow Articles by GILLY, W. F.
Right arrow Search for Related Content
PubMed
Right arrow Articles by YEE, A.
Right arrow Articles by GILLY, W. F.
Journal of Experimental Biology 128,287-305 (1987)
Published by Company of Biologists 1987

Mobilization of a Coordinated Escape Response by Giant Axons in the Ophiuroid, Ophiopteris Papillosa

AUDREY YEE 1, JAMES BURKHARDT 1, and W. F. GILLY 1

1 Hopkins Marine Station of Stanford University, Pacific Grove, CA 93950, USA

1. The escape response of Ophiopteris papillosa to contact by a predatory asteroid consists of a fast withdrawal of the stimulated arm, completed in less than 1 s, followed by rapid locomotion carried out by coordinated rowing of the two arms opposite the one stimulated.

2. Electrical activity recorded from the radial nerve cord (RNC) during the locomotory phase consists of small-amplitude spikes (<5 µV).

3. The initial arm jerk response is mediated by sequential activation of segmental intervertebral muscles, and the onset of activation progresses centrally at a rate of < 10cms-1 commencing 100-200ms after stimulation.

4. Electrical activity recorded from the RNC immediately after tubefoot stimulation consists of a burst of large-amplitude spikes (50-100 µV) that propagate centrally at approximately 50cms-1.

5. Electrical activity in the RNC with the lowest threshold to direct electrical stimulation consists of large spikes propagating at a mean velocity of 55 cms-1 at 13°C, and this activity persists in a Ca2--free medium.

6. Electrical and tubefoot stimulation of the arm tip in the same preparation both trigger a burst of large action potentials that propagate at approximately 50cms-1.

7. The identity of the giant axons activated by tubefoot stimulation, the pathways they follow and their role in mobilizing the coordinated escape response are discussed.

Note:
To whom reprint requests should be sent.

Key words: ophiuroid, escape, axon, echinoderm, nerve

Accepted on September 24, 1986






© The Company of Biologists Ltd 1987