A basic relationship between gastric and duodenal motilities in chickens

Area of Science:

• Gastroenterology
• Comparative Physiology
• Avian Biology

Background:

• Understanding gastrointestinal motility is key to avian digestion.
• Electrical activity patterns in the chicken gut are not fully characterized.
• Circadian rhythms and vagal nerve influence on gut function require further investigation.

Purpose of the Study:

• To characterize the electrical activity patterns of the chicken muscular stomach, duodenum, and ileum.
• To investigate the influence of feeding status, circadian rhythms, and vagotomy on these patterns.
• To explore the relationship between electrical activity and digesta propulsion in chickens.

Main Methods:

• Chronic implantation of electrodes in the muscular stomach, duodenum, and ileum of chickens.
• Recording of smooth muscle electrical activity under fed and fasted conditions with a 12-hour dark-light cycle.
• Assessment of vagotomy's effects on electrical activity patterns and propagation.

Main Results:

• Identified two major electrical activity patterns: rapid aboral (stomach) and oral (ileum) spike bursts, and slower aboral repetitive spike bursts.
• Aboral spike bursts showed a daytime circadian variation, abolished by vagotomy.
• Vagotomy increased oral spike burst frequency and altered repetitive spike burst patterns in fasted chickens, resembling feline patterns.

Conclusions:

• Chicken digesta propulsion may depend on the balance of aboral stomach and oral ileum electrical activity.
• Vagal innervation plays a significant role in regulating these electrical patterns and their circadian variations.
• Stomach activity level influences both aboral and oral electrical activity, impacting overall gut motility.