Figure 2.

Hypothetical mechanism of VP generation and propagation. Propagation of chemical signal, hydraulic signal or combination of these signals (hydraulic dispersion and turbulent diffusion) activated ligand-dependent or mechano-sensitive Ca²⁺ channels. Ca²⁺ influx inactivates H⁺-ATPase and induces long-term depolarization. Depolarization to AP threshold activates potential-dependent Ca²⁺ channels. Additional Ca²⁺ influx and plasma membrane depolarization activate potential-dependent Cl⁻ channels, and, later, K⁺-channels. As a result AP-like spike is formed.