First evidence of a living memory trace

What is a memory, physically, as it resides in the brain? Looks like there's progress finding out:

Scientists find first evidence of a living memory trace

An international team of scientists for the first time has detected a memory trace in a living animal after it has encountered a single, new stimulus. The research, done with honeybees sensing new odors, allows neuroscientists to peer within the living brain and explore short-term memory as never before, according to scientist Roberto Fernández Galán, a leading author on the report who is currently a postdoctoral research associate at Carnegie Mellon University.

What was it, exactly, that they found?

"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 Galán. "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."

Tags: memory, memory trace