Question

Discuss the main pathways underlying the bi-directional cross-talk between the gastrointestinal system and the brain. How is this cross-talk regulated by multiple signals including glucose, metabolic hormones and microbiota under the physiological condition? How can these pathways be targeted to develop potential treatments for some neurological disorders?

Answer 1

Discuss the main pathways underlying the bi-directional cross-talk between the gastrointestinal system and the brain.

The main pathways underlying the bi-directional cross talk between the gastrointestinal system and the brain is by the intercationof the immune cells, epithelial barrier, blood vessels, nerve cells that are intramurally located and smooth muscles. Mucosal mast cells would be able to detect any threats or antigenic agents or any noxious stimuli that might might generate or amplify the signals. MMCs and the enteric nervous system interact such that the cross talk between the brain and the gastrointestinal tract would take place. This is also referred to as the gut brain axis.

How is this cross-talk regulated by multiple signals including glucose, metabolic hormones and microbiota under the physiological condition?

Regulation of cross talk occurs via the gut brain axis, where there is passing on of signals from the microbiota to the brain and vice verse, thus resulting in a bi-directional communication. The role of the gut brain axis is integration of functions of the gut and linking of emotional as well as cognitive cen-ters along with the peripheral functions of the intestine. These regulate mechanisms such as activation of the immune system, permeability of the intestine.

This bi-directional communication allows for proper maintenance of homeostasis in a person. Efferent signals move from the CNS to the walls of the intestine and afferent signals move from the lumen, moving on to the enteric system to the CNS. These signals go via the autonomic nervous system and the hypothalamic pituitary adrenal. Input comes from the anterior cingulate cortex and the pre-frontal cortex. Integrated information comes from the orbitofrontal cortex and the pre frontal cortex.

Gut reactions to nociceptive stimuli would involve both the spinal as well as supraspinal reflexes, that would engage in strong autonomic and emotional responses. Circuit integration outside the gut wall involves engagement of circuits that are present outside the gut wall integrated with the interoceptive as well as the exteroceptive information for optimization of the homeostatic regulation of the function of the intestine.