cAMP responsive element-binding protein (CREB) is a transcription factor that can be activated through phosphorylation in the cAMP and PKA signaling pathway to bind CRE, thereby regulating the transcription of many different genes involving neuron growth and differentiation. (10).

After confirming a suspicion that sensitization occurs because of migration of certain kinases-again, PKA-into the nucleus of <em>Aplysia</em> neurons,  and knowing that PKA can activate CREB, Kandel went forward with research on this transcription factor's role in memory formation. In this paper, Dash, Hochner, and Kandel show that CREB is a)present in <em>Aplysia</em> sensory neurons and b)necessary for sensitization because of its involvement in long-term strengthening of synaptic connections. As described in another seminal paper, Bartsch, Kandel, et al. (1995) made the discovery that two forms of CREB exist: CREB-1 activates gene expression while CREB-2 represses gene expression (11). (12).  <strong>See also the clip of Dr. Kandel speaking about CREB-2 and significant research that this paper paved the way for under the interview tab</strong>.