The level of differentiation and function of the enteric nervous system in the chicken embryo

Any developmental disorder in enteric nervous system (ENS) may lead to congenital motility diseases of the gastrointestinal tract. The present study aimed to examine the structural differentiation and functional activity of the ENS in the Chick embryo. Ten Chick embryos were sacrificed at embryonic day 19 and then، their jejunum and colon specimens were collected. The isolated rings of the intestine were prepared and their motor activity was tested in an organ bath system. The contraction of the tissues was recorded in basic condition and following the stimulation by cholinergic and adrenergic agonists as well as the stimulation of the non-adrenergic-non-cholinergic system by electrical field stimulation (EFS). The structure of the intestinal specimen was assessed immuno-¹histochemically (IHC) using glial fibrillary acidic protein (GFAP) biomarker. Spontaneous rhythmic contractions were seen in both jejunum and colon specimens. Cholinergic stimulations significantly increased the amplitude of contractions in jejunum (p<0. 01) and colon (p<0. 001) tissues. However، adrenergic stimulation decreased significantly the amplitude of contractions in isolated tissues prepared from the jejunum (p<0. 05) and colon (p<0. 001). The EFS-induced decreases significantly the tension of isolated tissues pre-contracted with potassium chloride in both jejunum (p<0. 001) and colon (p<0. 001). The results of IHC were showed a positive immunoreactivity of enteric nervous ganglia with GFAP biomarker. It seems that the ENS in chick intestine is fully differentiated before birth and it can control the intestinal motility patterns in birds.