http://cognition.ups-tlse.fr/intranetbcnam/blogbcnam/index.php Copyright 2012, Martin Giurfa Martin Giurfa en-US SPHPBLOG 0.5.1 http://cognition.ups-tlse.fr/intranetbcnam/blogbcnam/index.php?entry=entry080305-172504
There are in fact 3 POW, related to the electrophysiological course given soon by R. Menzel in Toulouse (see added files).
Two of them describe neural plasticity at synapses of KC to output neurons, which displays hebbian properties (pre/post coincidence detection). A special focus on PE1 neuron (Menzel & Manz JEB 05) shows that even the cell does not respond to sensory stimulation, it shows neural plasticity. The other one (Cassenaer & Laurent, Nature 07) describes the relationship between the spike timing of KC and beta-lobe neuron relative to oscillations and the consequence on neural plasticity.
The third paper (Okada et al. JN 07) describes the effect of olfactory learning on PE1 discharges. An interesting model presents the MB as inhibitory structures over executive functions except for learned stimuli.
Menzel_JEB05.pdf
Cassenaer_&_Laurent_-_Nature_-_2007.pdf
Okada_et_al._JNRS 07.pdf
]]> Paper of the Week http://cognition.ups-tlse.fr/intranetbcnam/blogbcnam/index.php?entry=entry080305-172504 Martin Giurfa Wed, 05 Mar 2008 16:25:04 GMT http://cognition.ups-tlse.fr/intranetbcnam/blogbcnam/comments.php?y=08&m=03&entry=entry080305-172504 http://cognition.ups-tlse.fr/intranetbcnam/blogbcnam/index.php?entry=entry080211-171120 Nobuhiro Yamagata
Institute for Neurobiology, Free University of Berlin


Nobuhiro has studied and worked for his PhD in the group of Makoto Mizunami (Sendai University), performing electrophysiological recordings in the AL of ants. He has now spent two years in the Lab of Randolf Menzel, doing optical imaging of projections neurons in bees, recording in the mushroom body lip. Below is an abstract of his present interests, which he will share with us on :

Friday 15th, 12:15, 'Salle du Conseil de l'UFR-SVT'


Title: Odor coding in presynaptic boutons of the medial and lateral antenno-cerebral tract in the honeybee, Apis mellifera.
Odors are coded by the spatio-temporal distribution of excitation and inhibition at the level of the antennal lobe and in olfactory projection neurons. Projection neurons terminate in the lip region of the mushroom body calyces where they form presynaptic varicosities (boutons). These boutons are part of a microcircuit with the postsynaptic dendritic trees of the Kenyon cells and reciprocal synapses from inhibitory feedback neurons (Ganeshina et al. 2001). A recent study revealed that odors are represented in spatio-temporal combinations of multiple boutons (Szyszka et al. 2005). My study focuses on the question whether processing in these microcircuits leads to different response profiles and temporal dynamics in boutons from the same projection neuron. For this purpose, I stain projection neurons with the fluorescent dye Fura-2, a membrane impermeable calcium indicator, by inserting dye coated glass electrodes into soma clusters of the lateral or median antenno-cerebral tract (l- and m-ACT), and perform optophysiological measurements of calcium concentration changes of boutons. I am examining separately boutons from m- and l-ACT neurons with an attempt to test whether these two tracts of projection neurons code odors differently.

Relevant Litterature

Yamagata_J Comp Neurol_2007.pdf
Yamagata_Proc R Soc B_2006.pdf
Yamagata_Naturwissenschaften_2005.pdf ]]> http://cognition.ups-tlse.fr/intranetbcnam/blogbcnam/index.php?entry=entry080211-171120 Martin Giurfa Mon, 11 Feb 2008 16:11:20 GMT http://cognition.ups-tlse.fr/intranetbcnam/blogbcnam/comments.php?y=08&m=02&entry=entry080211-171120 http://cognition.ups-tlse.fr/intranetbcnam/blogbcnam/index.php?entry=entry080211-165956 Welcome to new visitors and members of the Bee Team!




Nathalie Stroeymeyt is a PhD student directed by Nigel Franks (Bristol) and Martin Giurfa (Toulouse). She works on aspects of individual learning in ants in a migratory context. She spends 70% of her time in Bristol and 30% in Toulouse where, as a fellow of the Ecole Normale Superieure, has to taught in several biology courses.





Petya Goergieva is an Erasmus student originaly from Bulgary, but studying biology at the University of Wuerzburg. She will spend 3 months in our group, working with Jean-Christophe and Edith on calcium imaging of odor-evoked activity in the lateral horn.





Yann Le Poul is a student from the Ecole Normale Supérieure (ENS) in Lyon. He will with us until May 16th, and will work with Martin and Jean-Marc on delay vs trace conditioning in the honeybee.

WE WISH THEM A BUSY AND SUCCESSFUL STAY IN THE LAB ! ]]> http://cognition.ups-tlse.fr/intranetbcnam/blogbcnam/index.php?entry=entry080211-165956 Martin Giurfa Mon, 11 Feb 2008 15:59:56 GMT http://cognition.ups-tlse.fr/intranetbcnam/blogbcnam/comments.php?y=08&m=02&entry=entry080211-165956 http://cognition.ups-tlse.fr/intranetbcnam/blogbcnam/index.php?entry=entry080103-121850 The team during a brain-storming session at La Chaumiere




MAY THIS BE A VERY PRODUCTIVE AND EXCITING YEAR FOR EVERYONE!!!

]]> http://cognition.ups-tlse.fr/intranetbcnam/blogbcnam/index.php?entry=entry080103-121850 Martin Giurfa Thu, 03 Jan 2008 11:18:50 GMT http://cognition.ups-tlse.fr/intranetbcnam/blogbcnam/comments.php?y=08&m=01&entry=entry080103-121850 http://cognition.ups-tlse.fr/intranetbcnam/blogbcnam/index.php?entry=entry071120-173207
Annu. Rev. Neurosci. 2007. 30:505–33

Molecular Architecture of Smell and Taste in Drosophila

Leslie B. Vosshall1 and Reinhard F. Stocker2

1Laboratory of Neurogenetics and Behavior, The Rockefeller University, New York,
NY 10021-6399; email: leslie@mail.rockefeller.edu
2Department of Biology, University of Fribourg, CH-1700 Fribourg, Switzerland;
email: reinhard.stocker@unifr.ch

The chemical senses—smell and taste—allow animals to evaluate and distinguish valuable food resources from dangerous substances in the environment. The central mechanisms by which the brain recognizes and discriminates attractive and repulsive odorants and tastants, and makes behavioral decisions accordingly, are not well understood in any organism. Recent molecular and neuroanatomical advances in
Drosophila have produced a nearly complete picture of the peripheral neuroanatomy and function of smell and taste in this insect. Neurophysiological experiments have begun to provide insight into the mechanisms by which these animals process chemosensory cues. Given the considerable anatomical and functional homology in smell and taste pathways in all higher animals, experimental approaches in
Drosophila will likely provide broad insights into the problem of sensory coding. Here we provide a critical review of the recent literature in this field and comment on likely future directions.


vosshall_AnnRN_07.pdf
]]> Paper of the Week http://cognition.ups-tlse.fr/intranetbcnam/blogbcnam/index.php?entry=entry071120-173207 Martin Giurfa Tue, 20 Nov 2007 16:32:07 GMT http://cognition.ups-tlse.fr/intranetbcnam/blogbcnam/comments.php?y=07&m=11&entry=entry071120-173207 http://cognition.ups-tlse.fr/intranetbcnam/blogbcnam/index.php?entry=entry071115-113433 Nature 450, 63-71 (2007)

Dissecting a circuit for olfactory behaviour in Caenorhabditis elegans

Sreekanth H. Chalasani1, Nikos Chronis1, Makoto Tsunozaki1, Jesse M. Gray1, Daniel Ramot2, Miriam B. Goodman2 & Cornelia I. Bargmann1

1 Howard Hughes Medical Institute, Laboratory of Neural Circuits and Behaviour, The Rockefeller University, New York, New York 10065, USA.
2 Program in Neurobiology and Department of Molecular and Cellular Physiology, Stanford University, Stanford, California 94305, USA.

Although many properties of the nervous system are shared among animals and systems, it is not known whether different neuronal circuits use common strategies to guide behaviour. Here we characterize information processing by Caenorhabditis elegans olfactory neurons (AWC) and interneurons (AIB and AIY) that control food- and odour-evoked behaviours. Using calcium imaging andmutations that affect specific neuronal connections, we show thatAWCneurons are activated by odour removal and activate the AIB interneurons through AMPA-type glutamate receptors. The level of calcium in AIB interneurons is elevated for several minutes after odour removal, a neuronal correlate to the prolonged behavioural response to odour withdrawal. The AWC neuron inhibits AIY interneurons through glutamate-gated chloride channels; odour presentation relieves this inhibition and results in activation of AIY interneurons. The opposite regulation of AIY and AIB interneurons generates a coordinated behavioural response. Information processing by this circuit resembles information flow from vertebrate photoreceptors to OFF bipolar and ON bipolar neurons, indicating a conserved or convergent strategy for sensory information processing.

Paper:
Chalasani_Nature_2007.pdf ]]> Paper of the Week http://cognition.ups-tlse.fr/intranetbcnam/blogbcnam/index.php?entry=entry071115-113433 Martin Giurfa Thu, 15 Nov 2007 10:34:33 GMT http://cognition.ups-tlse.fr/intranetbcnam/blogbcnam/comments.php?y=07&m=11&entry=entry071115-113433 http://cognition.ups-tlse.fr/intranetbcnam/blogbcnam/index.php?entry=entry071029-153305 Nature Neuroscience 10, 1474 - 1482 (2007)

Sensory processing in the Drosophila antennal lobe increases reliability and separability of ensemble odor representations

Vikas Bhandawat, Shawn R Olsen, Nathan W Gouwens, Michelle L Schlief & Rachel I Wilson

Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, Massachusetts 02115, USA.

Here we describe several fundamental principles of olfactory processing in the Drosophila melanogaster antennal lobe (the analog of the vertebrate olfactory bulb), through the systematic analysis of input and output spike trains of seven identified glomeruli. Repeated presentations of the same odor elicit more reproducible responses in second-order projection neurons (PNs) than in their presynaptic olfactory receptor neurons (ORNs). PN responses rise and accommodate rapidly, emphasizing odor onset. Furthermore, weak ORN inputs are amplified in the PN layer but strong inputs are not. This nonlinear transformation broadens PN tuning and produces more uniform distances between odor representations in PN coding space. In addition, portions of the odor response profile of a PN are not systematically related to their direct ORN inputs, which probably indicates the presence of lateral connections between glomeruli. Finally, we show that a linear discriminator classifies odors more accurately using PN spike trains than using an equivalent number of ORN spike trains.


Paper:
Bhandawat_Nat_Neurosci_2007.pdf


To read more:
Ng_Neuron_2002.pdf
Wang_Cell_2003.pdf
Pologruto_et_al_(Svoboda)_-_J_Neurosci_-_2004.pdf ]]> Paper of the Week http://cognition.ups-tlse.fr/intranetbcnam/blogbcnam/index.php?entry=entry071029-153305 Martin Giurfa Mon, 29 Oct 2007 14:33:05 GMT http://cognition.ups-tlse.fr/intranetbcnam/blogbcnam/comments.php?y=07&m=10&entry=entry071029-153305 http://cognition.ups-tlse.fr/intranetbcnam/blogbcnam/index.php?entry=entry071016-192420 The Journal of Neuroscience, October 10, 2007 • 27(41):11132–11138

Multiple Memory Traces for Olfactory Reward Learning in
Drosophila

Andreas S. Thum,1 Arnim Jenett,1 Kei Ito,2 Martin Heisenberg,1 and Hiromu Tanimoto1

1Lehrstuhl fuer Genetik und Neurobiologie, Biozentrum, Universitaet Wuerzburg, Am Hubland, D-97074 Wuerzburg, Germany, and 2Institute of Molecular and Cellular Biosciences, University of Tokyo, 113-0032 Tokyo, Japan

"Physical traces underlying simple memories can be confined to a single group of cells in the brain. In the fly Drosophila melanogaster, the Kenyon cells of the mushroom bodies house traces for both appetitive and aversive odor memories. The adenylate cyclase protein, Rutabaga, has been shown to mediate both traces. Here, we show that, for appetitive learning, another group of cells can additionally accommodate a Rutabaga-dependent memory trace. Localized expression of rutabaga in either projection neurons, the first-order olfactory interneurons, or in Kenyon cells, the second-order interneurons, is sufficient for rescuing the mutant defect in appetitive short-term memory. Thus, appetitive learning may induce multiple memory traces in the first- and second-order olfactory interneurons using the same plasticity mechanism. In contrast, aversive odor memory of rutabaga is rescued selectively in the Kenyon cells, but not in the projection neurons. This difference in the organization of memory traces is consistent with the internal representation of reward and punishment."
Read more...]]> Paper of the Week http://cognition.ups-tlse.fr/intranetbcnam/blogbcnam/index.php?entry=entry071016-192420 Martin Giurfa Tue, 16 Oct 2007 17:24:20 GMT http://cognition.ups-tlse.fr/intranetbcnam/blogbcnam/comments.php?y=07&m=10&entry=entry071016-192420 http://cognition.ups-tlse.fr/intranetbcnam/blogbcnam/index.php?entry=entry071016-183837 Aurore Avargues & Theo Rolla Paula Mota




Aurore got a PhD fellowship as a student of the Ecole Normale Superieure. Her PhD project studies complex problem solving in the visual domain in free-flying bees

Theo got a PhD fellowship from the Brazilian government. His PhD project studies color learning and processing in harnessed bees using calcium imaging and behavioral techniques. ]]> What's new ? http://cognition.ups-tlse.fr/intranetbcnam/blogbcnam/index.php?entry=entry071016-183837 Martin Giurfa Tue, 16 Oct 2007 16:38:37 GMT http://cognition.ups-tlse.fr/intranetbcnam/blogbcnam/comments.php?y=07&m=10&entry=entry071016-183837 http://cognition.ups-tlse.fr/intranetbcnam/blogbcnam/index.php?entry=entry071014-155241 OCTOBER - DECEMBER 2007



Vanesa Fernandez from the University of Buenos Aires (Social Insect Study Group)

Vanesa wants to study the potential involvement of biogenic amines such as dopamine in latent inhibition, in the framework of olfactory PER conditioning.




NOVEMBER - JANUARY 2008




Yukihisa Matsumoto (Yuki) from the University of Sendai, Japan.

Besides being in the Guinness Book of Records for his astonishing capacity of exterminating bees (normal sample sizes for Yuki are around 5000...), Yuki wants to spend some time here learning Ca2+ imaging techniques with JC.




NOVEMBER - JUNE 2008





Lisa Scheunemann from the Free University of Berlin, Germany.

After a passage in Toulouse 1 year ago, Lisa is back to work with Jean-Christophe, Valérie and Manu on the temporal role of calcium in the formation of the olfactory long-term memory. She also wants to examine the influence of pharmacological injections of calcium-dependent products on the calcium signal in different parts of the honeybee brain.

(Thanks to the artistic talent of Benoit for the great animation!)

]]> Visitors http://cognition.ups-tlse.fr/intranetbcnam/blogbcnam/index.php?entry=entry071014-155241 Martin Giurfa Sun, 14 Oct 2007 13:52:41 GMT http://cognition.ups-tlse.fr/intranetbcnam/blogbcnam/comments.php?y=07&m=10&entry=entry071014-155241