The liver is also a neurologic organ that is innervated by nerve. As a neurologic organ, the liver metabolizes and responds to the change of neurotransmitters, such as glutamate, under liver disease state. Among many neurotransmitters, glutamate is one of the main excitatory neurotransmitters acting in the central nervous system. The present findings provide strong support to the emerging concept that the neurotransmitter function of glutamate is not limited to the brain. In the liver, elevated glutamate leads to upregulation of metabotropic glutamate receptor in hepatic stellate cells, resulted in alcoholic hepatic steatosis.

Furthermore, the pathological changes in the endocannabinoid system can lead to the development of several chronic liver diseases. Cannabinoid receptors and their ligands have critical roles in the pathogenesis of steatosis and liver fibrosis. The activation of cannabinoid receptor-mediated signaling pathways may differ depending on the type of cells stimulated. We aim to explore the effects of neurotransmitters and their mechanisms in liver diseases and discover novel therapeutic targets for treating liver disease.