The Ubiquity Nature of Acetylcholine

Acetylcholine (ACh) was viewed as the “vagusstoff” after Loewi`s experiment with the frog heart [1]. In 1936 Otto Loewi, and Henry Dale were recipients of the Nobel Prize in Physiology and Medicine, by their contribution for the acetylcholine discover as a neurotransmitter [1]. So, ACh was regarded as a neurotransmitter during several decades [2]. After that it was evidenced a widespread expression of the cholinergic system within a variety of non-neuronal tissues. The “Non-Neuronal Cholinergic System” (NNCS) is well established as the extra-neural effects of acetylcholine [3]. Beyond these neural and non neuronal cholinergic systems there is another one named by Tracey et al. as the Cholinergic Anti-Inflammatory Pathway (CAIP) [4]. Afferent and efferent signals transmitted in the vagus nerve are components of a neural circuit that modulates the innate immune response. The CAIP could be considered as a liaison between the cholinergic neural system and NNCS.