Sun, 20 Jul 2008 21:08:15 BST CiteULike: brembs visual http://www.citeulike.org/user/brembs/tag/visual CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/brembs/article/1421811 <i>Science, Vol. 316, No. 5833. (29 June 2007), pp. 1901-1904.</i><br /><br />Drosophila melanogaster can make appropriate choices among alternative flight options on the basis of the relative salience of competing visual cues. We show that this choice behavior consists of early and late phases; the former requires activation of the dopaminergic system and mushroom bodies, whereas the latter is independent of these activities. Immunohistological analysis showed that mushroom bodies are densely innervated by dopaminergic axons. Thus, the circuit from the dopamine system to mushroom bodies is crucial for choice behavior in Drosophila. 10.1126/science.1137357 Dopamine-Mushroom Body Circuit Regulates Saliency-Based Decision-Making in Drosophila Ke Zhang Jian Guo Yueqing Peng Wang Xi Aike Guo doi:10.1126/science.1137357 Science, Vol. 316, No. 5833. (29 June 2007), pp. 1901-1904. 2007-06-29T08:23:23-00:00 2007 Science 316 5833 1901 1904 bodies decision-making drosophila learning memory mushroom visual http://www.citeulike.org/user/brembs/article/950204 <i>Learn Mem, Vol. 13, No. 5. (t 2006), pp. 618-628.</i><br /><br />In a permanently changing environment, it is by no means an easy task to distinguish potentially important events from negligible ones. Yet, to survive, every animal has to continuously face that challenge. How does the brain accomplish this feat? Building on previous work in Drosophila melanogaster visual learning, we have developed an experimental methodology in which combinations of visual stimuli (colors and patterns) can be arranged such that the same stimuli can either be directly predictive, indirectly predictive, or nonpredictive of punishment. Varying this relationship, we found that wild-type flies can establish different memory templates for the same contextual color cues. The colors can either leave no trace in the pattern memory template, leading to context-independent pattern memory (context generalization), or be learned as a higher-order cue indicating the nature of the pattern-heat contingency leading to context-dependent memory (occasion setting) or serve as a conditioned stimulus predicting the punishment directly (simple conditioning). In transgenic flies with compromised mushroom-body function, the sensitivity to these subtle variations is altered. Our methodology constitutes a new concept for designing learning experiments. Our findings suggest that the insect mushroom bodies stabilize visual memories against context changes and are not required for cognition-like higher-order learning. Context and occasion setting in Drosophila visual learning. B Brembs J Wiener doi:10.1101/lm.318606 Learn Mem, Vol. 13, No. 5. (t 2006), pp. 618-628. 2006-11-17T14:42:36-00:00 2006 Learn Mem 1072-0502 13 5 618 628 behavior classical condijtioning conditioning context drosophila generalization learning memory neurobiology neuroscience occasion operant pavlovian setting visual