Figure 2.

Glial mechanisms for intercellular communication with enteric neurons. (A) Enteric glia express a series of receptors for neurotransmitters that elicit calcium responses and subsequent events leading to gliotransmission. (B) A special unit is found between purinergic neurons and enteric glia, where ATP release via pannexin-1 recruits adjacent enteric glia, a process that probably accounts for pathology or injury. (C) Glial responses can be processed at the cellular and network level by hemichannels containing connexin 43. When Cx43 is absent, gastrointestinal dysfunction can be manifested as dysmotility. (D) During inflammation, the interaction of purines in intercellular communication in the enteric nervous system is evidenced by causing enteric neuron death via ATP release by enteric glia, participation of P2X2 receptors during neuroinflammation, and release of several inflammatory mediators, such as S100B. CA=catecholamines, Glu=glutamate, GPCR=G protein-coupled receptor, PGs=prostaglandins.