Odor Coding and Hebbian Reverberations in the Antennal Lobe of Honeybee

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Dear colleagues,

I’m very pleased to announce the online publication of my PhD thesis at the
server of the Humboldt University (see link below).

The title of my dissertation is “Odor Coding and Memory Traces in the
Antennal Lobe of Honeybee: Computational Studies of Neural Dynamics Based on
Calcium-Imaging Data”.

The analysis of calcium-imaging data reveals two major novel results. The
first one is on sensory coding and the second one on short-term memory.
Concerning sensory coding it is shown that the neural dynamics of the
antennal lobe converge to odor-specific attractors. The time interval
required to achieve the attractors is approx. 800 ms, regardless of odor
identity and concentration. However, the neural dynamics driven by different
odors can be well discriminated already after 300 ms, as shown with an
analysis based on support-vector classifiers. Predictions on behavioral
experiments are reported. The disagreement of our results with other
hypotheses and models on olfactory coding is extensively discussed.

Concerning short-term memory, experimental evidence of Hebbian
reverberations in the antennal lobe is provided for the first time at the
network level. In particular it is shown that a single, unrewarded odor
presentation induces changes of pairwise correlations between olfactory
glomeruli. This phenomenon can be interpreted as a biological implementation
of the Hebbian learning rule used in computational models. Furthermore, it
is mathematically shown how to retrieve the last odor presented from the
spontaneous activity of the antennal lobe after stimulation. The relevance
of these results is discussed in detail.

http://dochost.rz.hu-berlin.de/dissertationen/fernandez-galan-roberto-2003-1
2-17/PDF/Fernandez-Galan.pdf

Please feel free to contact me for further information of if you have any
problems to download the file.

Best regards,
Roberto Fernández Galán

Department of Biological Sciences and
Center for the Neural Basis of Cognition
4400 Fifth Avenue
Mellon Institute
Carnegie Mellon University
Pittsburgh, PA 15213
Phone: 412-268-9818
e-mail: galan@cnbc.cmu.edu

• Previous message: Maneesh Sahani: "Graduate study at the Gatsby Computational Neuroscience Unit"
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