We have all heard the saying “thinking with one’s stomach,” a cliché that suggests basing one’s critical thought processes on the whims of their digestive system. However, there may be more than a little truth to this saying. Often referred to as the body’s “second brain,” the enteric nervous system (ENS) comprises a complex network of neurons and ganglia embedded within the walls of the gastrointestinal tract. In recent years, researchers have increasingly recognized the significance of the ENS and its application in physiological research.
The ENS is a division of the autonomic nervous system (ANS) responsible for regulating the digestive process. It consists of millions of neurons spread throughout the esophagus, stomach, small intestine, and large intestine. These neurons form an intricate network that can function independently of the central nervous system (CNS) but also communicates with it. The ENS controls essential gastrointestinal functions, such as peristalsis, secretion of digestive enzymes, and blood flow regulation within the gut.
Several effective techniques are available to researchers to evaluate and measure ENS activity for their studies. Electrogastrography (EGG) provides a noninvasive approach to measuring the electrical activity of the stomach muscles. EEG can help researchers understand the rhythm and coordination of stomach contractions, aiding in the diagnosis of motility disorders.
In addition to EGG, a range of other physiological signals may be applied to ENS research. A recent study published in the June 2023 edition of Nature Communication investigated the gut-brain relationship by measuring physiological response to stimulation of the digestive system via different noninvasive techniques: EGG, electroencephalogram (EEG), skin conductance response (SCR), heart rate (HR), and heart rate variability (HRV). Research participants ingested a small vibrating probe that provided varying levels of stimulation as it passed through the lower digestive tract. EGG, EEG, and SCR signals were recorded along with hemodynamic signals via a BIOPAC data acquisition and analysis system. Researchers concluded that these techniques provided a viable alternative to more invasive approaches to measuring the body’s response to sensory stimulation of the digestive tract with, according to the published report, “implications for understanding gut feelings and gut-brain interactions in healthy and clinical populations.”
More invasive techniques for studying the ENS can still provide researchers with valuable data. A 2023 study by a team of South Korean researchers investigated how radial stretching affects intestinal contractions. The study also examined how drugs targeting the ENS affect such contractions to develop treatments for gastrointestinal disorders. Samples of intestinal tissue were taken from participants undergoing aggressive treatment for colorectal cancer. Samples were preserved in a tissue chamber and connected to a BIOPAC isometric force transducer to measure contractions, with data recorded and analyzed with a BIOPAC MP160 system running AcqKnowledge software. The study was able to detect regional differences in the stretch reflex of colon tissue via electrophysiological recordings of intestinal smooth muscles.
These are some of the ways in which researchers are currently using BIOPAC technologies to better understand the relationship between the ENS and other neurophysiological processes. For additional information on this topic, see our page on AcqKnowledge’s Gastric Myoelectric Activity feature and our EGG citations.
If you would like to know more about how BIOPAC can help you plan and equip your ENS study, reach out to your regional sales representative today.