Small intestinal transections decrease the occurrence of tapeworm-induced myoelectric patterns in the rat

Area of Science:

• Gastroenterology
• Neurogastroenterology
• Parasitology

Background:

• Luminal infection by the tapeworm Hymenolepis diminuta affects rat small intestinal myoelectric activity.
• The enteric nervous system (ENS) coordinates gastrointestinal motility.

Purpose of the Study:

• To evaluate the role of enteric nervous system (ENS) continuity between the small intestine, stomach, and colon in tapeworm-induced myoelectric pattern changes.
• To determine if an intact ENS is necessary for specific tapeworm-induced myoelectric responses.

Main Methods:

• 32 rats were surgically prepared with electrodes to record myoelectric activity.
• Intestinal transections and anastomoses were performed in 16 rats to disrupt ENS continuity.
• Rats were infected with H. diminuta, and myoelectric patterns including migrating myoelectric complex (MMC) phase III, slow wave activity, repetitive bursts of action potentials (RBAP), and sustained spike potentials (SSP) were measured.

Main Results:

• In infected rats, double intestinal transection significantly reduced the frequency of RBAP and SSP.
• Intestinal transection did not alter infection-induced decreases in MMC phase III frequency or slow wave-associated spike potentials.
• A continuous ENS is necessary for the full expression of certain tapeworm-induced myoelectric patterns.

Conclusions:

• A small intestinal ENS that is continuous with the stomach/pylorus and colon/caecum is required for maximal tapeworm-induced SSP and RBAP myoelectric activity.
• ENS continuity plays a critical role in mediating the complex motor responses to parasitic infections in the gut.