Abstract: The influence of the learning process on the persistence
of the newly acquired behavior is relevant both for our knowledge of
the learning/memory mechanisms and for the educational policy. However,
it is unclear whether during an operant conditioning process with
a continuous reinforcement paradigm, individual differences in acquisition
are also associated to differences in persistence of the acquired
behavior. In parallel, adult neurogenesis has been implicated in spatial
learning and memory, but the specific role of the immature neurons
born in the adult brain is not well known for this process. We have
addressed both questions by analyzing the relationship between water
maze task acquisition scores, the persistence of the acquired behavior,
and the size of the different subpopulations of immature neurons in the
adult murine hippocampus. We have found that task acquisition and
persistence rates were negatively correlated: the faster the animals find
the water maze platform at the end of acquisition stage, the less they
persist in searching for it at the learned position in a subsequent nonreinforced
trial; accordingly, the correlation in the number of some
new neurons? subpopulations and the acquisition rate is negative while
with persistence in acquired behavior is positive. These findings reveal
an unexpected relationship between the efficiency to learn a task and
the persistence of the new behavior after a non-reinforcement paradigm,
and suggest that the immature neurons might be involved in different
roles in acquisition and persistence/extinction of a learning task.
