Mediated by ion channel lonotropic receptor Mediated by G-protein coupled receptor Metabotropic receptor,G-protein,effecter enzyme AC-cAMP-PKA PLC-IP3-Ca2+-CaM PLC-DG-PKC G-protein-ion channel Mediated by tyrosine kinase receptor Tyrosine kinase receptor receptor-associated tyrosine kinase * Mediated by ion channel Ionotropic receptor * Mediated by G-protein coupled receptor Metabotropic receptor, G-protein, effecter enzyme AC-cAMP-PKA PLC-IP3 -Ca2+ -CaM & PLC-DG-PKC G-protein-ion channel * Mediated by tyrosine kinase receptor Tyrosine kinase receptor receptor-associated tyrosine kinase