| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, United States
2 The Salk Institute for Biological Studies, La Jolla, California, United States
3 Biology, California Institute of Technology, Pasadena, California, United States
* To whom correspondence should be addressed. E-mail: laurentg{at}caltech.edu.
Learning and memory has been studied extensively in Drosophila, using behavioral, molecular and genetic approaches. These studies have identified the mushroom body as essential for the formation and retrieval of olfactory memories. We investigated odor responses of the principal neurons of the mushroom body, the Kenyon cells (KCs), in Drosophila, using whole-cell recordings in vivo. KC responses to odors were highly selective, and thus sparse, compared to those of their direct inputs, the antennal lobe projection neurons (PNs). We examined the mechanisms that might underlie this transformation and identified at least three contributing factors: (i) excitatory synaptic potentials (from PNs) decay rapidly, curtailing temporal integration; (ii) PN convergence onto individual KCs is low (~10 PNs per KC on average), and (iii) KC firing thresholds are high. Sparse activity is thought to be useful in structures involved in memory, in part because sparseness tends to reduce representation overlaps. By comparing activity patterns evoked by the same odors across olfactory receptor neurons and across KCs, we show that representations of different odors do indeed become less correlated as they progress through the olfactory system.
This article has been cited by other articles:
|
|
 |
|
  A. Yarali, S. Ehser, F. Z. Hapil, J. Huang, and B. Gerber Odour intensity learning in fruit flies Proc R Soc B, October 7, 2009; 276(1672): 3413 - 3420. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. Demmer and P. Kloppenburg Intrinsic Membrane Properties and Inhibitory Synaptic Input of Kenyon Cells as Mechanisms for Sparse Coding? J Neurophysiol, September 1, 2009; 102(3): 1538 - 1550. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 N. K. Tanaka, K. Ito, and M. Stopfer Odor-Evoked Neural Oscillations in Drosophila Are Mediated by Widely Branching Interneurons J. Neurosci., July 1, 2009; 29(26): 8595 - 8603. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. D. Armstrong and J. I. van Hemert Towards a virtual fly brain Phil Trans R Soc A, June 13, 2009; 367(1896): 2387 - 2397. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Wang, A. Mamiya, A.-s. Chiang, and Y. Zhong Imaging of an Early Memory Trace in the Drosophila Mushroom Body J. Neurosci., April 23, 2008; 28(17): 4368 - 4376. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
