Pancreas-brain's Neural Circuitry

Introduction of Pancreas and Neural Network

The pancreas is mainly composed of two parts, namely the exocrine pancreas and the endocrine pancreas. There are also two major cell types for the exocrine pancreas, including the acinar cells and the ductal cells. The exocrine pancreas helps digestion by secreting digestive enzymes and bicarbonate.

The endocrine pancreas is composed of β cells that secrete insulin, α cells that secrete glucagon, δ cells that secrete somatostatin, and other cells that secrete pancreatic polypeptides. The endocrine pancreas is important for the maintenance of glucose homeostasis. Some studies showed that both the exocrine pancreas and the endocrine pancreas are controlled by both the parasympathetic and sympathetic nervous systems.

Fig.1 Cartoon representation of the vagal islet-brain axis. (Makhmutova, 2019)

Neurotransmitters in Central Pathways Regulating the Pancreas

It has been reported that the brainstem plays a key role in the regulation of autonomic outflow to the pancreas. There are a series of neurotransmitters that regulate the pancreas.

• GABA and Glutamate

GABA is the major inhibitory synaptic input that can also regulate vagal outflow to the pancreas. GABA produces tonic inhibition of pancreatic exocrine secretion and insulin release. Glutamate provides major excitatory synaptic input; it is one of the principal neurotransmitters in synapses impinging onto pancreas-projecting DMV neurons.

• Pancreatic Polypeptide

The release of PP is mediated by the vagus nerve. It has been shown that PP modulates PES, but not endocrine pancreatic secretions. In addition, nearly half of the identified pancreatic projection DMV neurons respond to PP.

• Cholecystokinin

CCK acts through its paracrine effect on the sensory neurons of the vagus nerve and its effect on the dorsal vagus nerve complex. CCK can directly affect the function of acinar cells through CCK receptors on acinar cells.

• Glucagon-like peptide-1

Released from intestinal cells, it can bind to receptors on pancreatic cells to stimulate insulin release. According to actions on DMV neurons and pancreatic cells, GLP-1 can increase pancreatic endocrine secretions.

• Serotonin

Serotonin, also known as 5-hydroxytryptamine, can regulate pancreatic secretions through direct and indirect effects. The interaction with CCK can regulate the neural control of pancreatic function.

The research of pancreas-brain's neural circuitry would be helpful for the development of selective drugs against specific diseases, such as pancreatic exocrine or endocrine dysfunctions, gastroparesis, and gastrointestinal reflux disorders. Creative Biolabs is one of the well-recognized experts who are professional in applying advanced platforms for a broad range of neurosciences research. If you are interested in our services and products, please do not hesitate to contact us for more detailed information.

References

1. Babic, T.; Travagli, R. Neural control of the pancreas. Pancreapedia: The Exocrine Pancreas Knowledge Base. 2016.
2. Makhmutova, M. Pancreatic Islets Communicate With the Brain via Vagal Sensory Neurons. University of Miami. 2019.

For Research Use Only. Not For Clinical Use.