Mathematical Modeling of Sustainable Synaptogenesis by Repetitive Stimuli Suggests Signaling Mechanisms In Vivo
A, B and C: synaptic maintenance occurs when stimulation exceeds the threshold. Repetitive stimuli with very short intervals (B) or a single strong stimulation (C) may exceed the threshold and induce synaptic maintenance. This mechanism cannot explain the necessity for repetitive stimuli with appropriate intervals (A). D: Repetitive stimuli with appropriate intervals induce different signal transduction cascades in each stimuli. At first, the first stimulation (Stim. 1) induces Protein 1 synthesis. Next, the second stimulation (Stim. 2) induces Protein 2 synthesis via Protein 1. Lastly, the third stimulation (Stim. 3) induces Protein 3 synthesis with the intermediation of Protein 2. Protein 3 may play a direct and important role in long-term synaptic maintenance.