The encoding of long-term associative memories for learned behaviors is a fundamental brain function.
Yet, how behavior is stably consolidated and retrieved in the vertebrate cortex is poorly understood.
We trained zebrafish in aversive reinforcement learning and measured calcium signals across
their entire brain during retrieval of the learned response. A discrete area of dorsal telencephalon
that was inactive immediately after training became active the next day. Analysis of the identified area
indicated that it was specific and essential for longterm memory retrieval and contained electrophysiological
responses entrained to the learning stimulus.
When the behavioral rule changed, a rapid spatial
shift in the functional map across the telencephalon
was observed. These results demonstrate that the
retrieval of long-term memories for learned behaviors
can be studied at the whole-brain scale in
behaving zebrafish in vivo. Moreover, the findings
indicate that consolidated memory traces can be
rapidly modified during reinforcement learning.