A developmental switch in the signaling cascades for LTP induction.

Long-term potentiation (LTP) is thought to be critically involved not only in learning and memory, but also during the activity-dependent developmental phases of neural circuit formation and refinement. Whether the mechanisms underlying LTP change during this phase of postnatal development, however, is unknown. We report here that, unlike LTP in the more mature CA1 region of the hippocampus, LTP in neonatal rodent hippocampus (<9 postnatal days, <P9) requires cyclic AMP-dependent protein kinase A (PKA) but not Ca(2+)/calmodulin-dependent protein kinase II (CaMKII).