Figure 1: The contribution of particular neurotransmitters in colonic homeostasis. The homeostasis of colon activity is regulated by vasoconstrictory stimuli, including cAMP, anti-inflammatory cytokines, inhibition of NF-?B and Th-2 mode of immune response (left side of figure) and vasodilatory stimuli, including cGMP, pro-inflammatory cytokines, activation of NF-?B and Th-1 mode of immune response (right side of the figure).