Neuropsin-dependent and -independent behavioral tagging.

AIM

The consolidation of short-term memories into long-term memories is promoted by associations with novel environmental stimuli. This phenomenon is known as behavioral tagging. Neuropsin, a plasticity-related serine protease in the hippocampus and amygdala, is involved in memory formation. This study investigated how neuropsin affects associative long-term memory.

METHODS

Short-term and long-term memory were assessed in control and neuropsin-deficient mice by investigating their performance in inhibitory avoidance and spatial object recognition tasks. The effect of exposure to novelty on the conversion of short-term memory to associative long-term memory was also examined.

RESULTS

The consolidation of task-related short-term memories into long-term memories was facilitated by exposing the animals to a novel environment 1 hour before training. However, this long-term memory conversion was impaired in neuropsin-deficient mice performing the inhibitory avoidance task but not the spatial object recognition task.

CONCLUSION

Behavioral tagging occurs via neuropsin-dependent and neuropsin-independent processes for different behavioral tasks.