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


spacer gif
     Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents    

First published online January 31, 2007
Journal of Experimental Biology 210, 561-569 (2007)
Published by The Company of Biologists 2007
doi: 10.1242/jeb.02697
This Article
Right arrow Summary Freely available
Right arrow Full Text
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 Similar articles in PubMed
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 Yafremava, L. S.
Right arrow Articles by Gillette, R.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Yafremava, L. S.
Right arrow Articles by Gillette, R.

Orienting and avoidance turning are precisely computed by the predatory sea-slug Pleurobranchaea californica McFarland

Liudmila S. Yafremava1, Christopher W. Anthony2, Laura Lane2, Jessica K. Campbell2 and Rhanor Gillette1,2,3,*

1 Program in Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, University of Illinois, Urbana, IL 61801, USA
2 Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, University of Illinois, Urbana, IL 61801, USA
3 The Neuroscience Program, University of Illinois at Urbana-Champaign, University of Illinois, Urbana, IL 61801, USA


Figure 1
View larger version (5K):
[in this window]
[in a new window]

  		Fig. 1. Stimulus application protocol. Nine stimulus loci were distinguished on the oral veil, with 0 designating midline, and +4 and –4 designating the right and left tentacle, respectively.

 

Figure 2
View larger version (9K):
[in this window]
[in a new window]

  		Fig. 2. Unilateral applications of chemotactile stimulus resulted in linear relationship between the turn angle and stimulus locus. (A) Responses to the appetitive stimulus betaine (crosses) and to the aversive stimulus taurine (filled circles). (B) The slope of the relationship in A for appetitive stimulus increases with the stimulus concentration. Values are means ± s.e.m.; for correlation coefficients, see text.

 

Figure 3
View larger version (6K):
[in this window]
[in a new window]

  		Fig. 3. Animals overshoot in orienting turns by approximately a factor of 4. (A) If animals were turning to position the stimulus in the center of their oral veil, then the angle of turn would relate to the stimulus locus according to the relationship: angle=arctan (xk/4), where k is the ratio of the oral veil width to the body length L (solid line without datapoints in B). (B) The relationship determined from data (solid line with data points, replotted from Fig. 2A) gives a slope 4 times steeper than the predicted relationship for k=0.3.

 

Figure 4
View larger version (6K):
[in this window]
[in a new window]

  		Fig. 4. Sequential turns stimulated by a single stimulus application. A significant fraction of animals performed multiple turns in response to unilateral oral veil stimulation. Three turns were most common, of which the first and third turn angles had the animals going in a closely similar direction. The second turn angle, to the opposite direction, was not correlated with the first or third. See text for further details.

 

Figure 5
View larger version (6K):
[in this window]
[in a new window]

  		Fig. 5. (A) Correlation analysis of 17 cases of sequential turns showed that the angle of the third turn was highly correlated with and was not significantly different from the angle of the first turn (r=0.84). (B) The second angle and first angle were not correlated (r=0.08).

 

Figure 6
View larger version (7K):
[in this window]
[in a new window]

  		Fig. 6. A summary model of function in turn behavior. Chemotactile afferents of oral veil are conceived as being integrated in an interneuronal layer that averages amplitude and laterality of chemotactile input. The output of the interneuronal layer is translated to the turn motor network through a switch mechanism regulated by the animal's appetitive state and memory of experience. The switch acts to invert the laterality of the output to the turn motor network to result in orienting or avoidance turns.

 




© The Company of Biologists Ltd 2007