Figure 1.

BNP/NPR-A/PKG-I/BK_Ca channel signaling in small primary afferent neurons during nociceptive processing (Zhang et al., 2010). NPR-A activation by BNP increases intracellular cGMP levels, leading to the activation of PKG-I and subsequent phosphorylation of BK_Ca channels. Activation of this signaling pathway is restricted to peptidergic DRG neurons. It results in reduced transmission of noxious heat stimuli in the presence of extracellular glutamate that increases intracellular Ca²⁺. How BNP is released from primary afferent neurons remains to be elucidated.