Posted by Monique

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

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

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 !

The team during a brain-storming session at La Chaumiere




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

Posted by Monique

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.


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