Capturing these memory traces could ultimately provide a completely new way to understand how short-term memory works, stated Galn. The findings are scheduled for January publication in Neural Computation.
"Our findings show that an odor produces a memory trace of synchronized neural activity that lasts several minutes after a bee initially senses it," said Galn. "This is the first time anyone has revealed a short-term, stimulus-specific neural pulse within the living brain that occurs after exposure to a previously unknown stimulus."
"Future investigations along the lines of our study may reveal previously overlooked memory traces in many other neural systems," said C. Giovanni Galizia, Galn's primary collaborator, who is now a professor at Konstanz Universitt in Konstanz, Germany.
Galn performed the work as part of his dissertation research while in the research group of Andreas Herz at the Humboldt University in Berlin, Germany.
The report supports Hebb's theory of learning, a 55-year-old proposition that "neurons that fire together wire together," thereby strengthening their connections. According to the theory, a stimulus activates some neurons while inhibiting others. Once this stimulus is removed, traces of that excitation/inhibition pattern so-called Hebbian reverberations should remain.
"We are the first to observe this phenomenon at the network level. We are also the first to detect a distinct signature, not only of a sensory short-term memory, but
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Contact: Lauren Ward
wardle@andrew.cmu.edu
412-268-7761
Carnegie Mellon University
14-Nov-2005