[Transit stage of the long-term facilitation in command neurons of the defensive behavior in sensitized snails].

Sensitising stimuli caused a synaptic facilitation of the Helix lucorum of responses to testing sensory stimulation which lasted over 24 hrs. Following a single stimulus, the facilitation was transient. The same facilitation occurred after 5-HT or cAMP application. Calmodulin and glutamate NMDA-receptor antagonists, as well as the protein synthesis inhibitors suppressed the facilitation in command neurones. The transient synaptic facilitation seems to involve processes of translation/transcription and subsequent synthesis of synapse-specific protein molecules with short life-time.