[Formation of C/EBP transcription factors and possible ways of regulation of their activity during learning in Helix].

Defensive conditioning in Helix is associated with activation of C/EBP family of transcription factors. The incubation of the CNS with serotonin that imitates the effects of conditioning or stimulation of adenylate cyclase with forscolin also increase the DNA-binding activity of C/EBP. The induction of protein kinase C by phorbol ester does not stimulate the formation of these transcription complexes. However, a slight increase in the cAMP-induced influence on the activation of C/EBP transcription factors was observed during a combined action of phorbol ester and serotonin. The more substantial cAMP-induced rise in DNA-binding activity of C/EBP family transcription factors was observed during increase in the intracellular Ca2+ concentration (incubation of the CNS with calcium ionophor A23187 and forscolin). Thus, the convergence of Ca2+ and cAMP-dependent regulating signals that reflect the interaction of different modal stimuli during learning can produce the intensification of formation of the C/EBP transcription complexes.