The enteric nervous system (ENS) is a complex division of the peripheral nervous system. Enteric neurons and glia cells are arranged in networks of enteric ganglia in the wall of the oesophagus, stomach, and intestine. The myenteric plexus is located between the longitudinal and circular muscle layers of the gut; its main function is to control the gastrointestinal motility. Submucous ganglia reside in the submucosa tissue layer, in small animals in one layer, in bigger animals, and in humans in two layers. This plexus regulates absorption, blood flow, secretion in the gut wall, and fluid movement between the lumen and the intestinal epithelia. Enteric neurons are highly varied in their morphological, neurochemical, and functional properties. Intrinsic primary afferent neurons, interneurons, and motor neurons are all present in the ENS and they form local neural circuits in the gastrointestinal tract.

Even with their local reflex circuits the ENS can work autonomously; it communicates bidirectionally with the central nervous system and the other parts of the peripheral nervous system. Recent data have elucidated that the gut-brain axis has a role in the development of neurodegenerative diseases or neuropsychological disorders. In addition, given the growing evidence showing the key role of the gut microbiota in physiology, the investigation of the microbiota-gut-brain axis provides a new research direction for the study of gastrointestinal and neurological diseases.

The aim of this special issue is to highlight that the pathological alterations of the ENS can cause not only gastrointestinal diseases but more complex disorders.

The special issue will be open for original research articles as well as review articles focusing on several aspects of pathological state of the ENS.

Potential topics include but are not limited to the following:

• Alterations in the gut-brain axis
• Alterations in the microbiota-gut-brain axis
• Neurodegenerative or neuropsychological disorders and the ENS
• Metabolic diseases and the ENS
• Dysbiosis and the ENS
• Diet and the ENS
• The influence of inflammation on the ENS
• Background of the intestinal dysmotility
• Developmental disturbances in the ENS
• Effects of aging on the ENS
• Pathophysiology and clinical implications