Memory Mechanisms: A common cascade for long-term memory Yukiko Goda  Current Biology  Volume 5, Issue 2, Pages 136-138 (February 1995) DOI: 10.1016/S0960-9822(95)00034-0

Figure 1 Production of cAMP by adenylate cyclase activates PKA. To establish long-term memory, the active catalytic subunit of PKA travels back to the nucleus where it phosphorylates CREB; CREB dimers subsequently promote transcription of genes through CRE sequences. The site of PKA activation required for long-term memory, whether presynaptic or postsynaptic, is not yet known. Current Biology 1995 5, 136-138DOI: (10.1016/S0960-9822(95)00034-0)