Abstract
Recently, embryonic stem (ES) cells were shown to spontaneously (without LIF) give rise to a functional organ-like unit, the "ES gut", which undergoes rhythmic contractions and is comprised of enteric derivatives of all three embryonic germ layers: epithelial cells (endoderm), smooth muscle cells and interstitial cells of Cajal (ICCs) (mesoderm), and a small number of enteric neurons (ectoderm), but no ganglia. The ICC network within the GI tract is responsible for the generation of electrical pacemaker activity. Enteric neurons present within the GI tract innervate the smooth muscle and are essential for peristalsis. By adding brain-derived neurotrophic factor (BDNF)(10−8 g/ml) only during EB formation, we for the first time succeeded in in vitro formation of enteric neural ganglia with connecting nerve fiber tracts (ENS) from enteric neural crest-derived cells in the ES gut. Moreover, focal stimulation of ES guts with ENS elicited propagated increases in intracellular Ca2+ concentration ([Ca2+]i) at single or multiple sites that were attenuated by nicotinic or muscarinic receptor blockade, or abolished by a neurotoxin, TTX. A 5-HT4 receptor agonist elicited increases in [Ca2+]i in the "ES gut" with enteric nervous system. This work was supported by Grants-in-aid for Scientific Research (14657311,16650090,17300130 and 18630007 for MT and 15300134 for SN) from the Ministry of Education, Science, Sports and Culture of Japan. [J Physiol Sci. 2007;57 Suppl:S16]
