Do salivary neurotrophic factors provide neurotrophic support to neurons of the central and peripheral nervous systems including nerves innervating papillae on the tongue?

Xerostomia, or loss of saliva, can lead to degeneration of taste papillae on the tongue. Saliva contains neurotrophic factors such as nerve growth factor and epidermal growth factor. These neurotrophic factors are likely to be important for the maintenance of the peripheral nervous system. Furthermore, neurotrophic support of peripheral nerves by salivary neurotrophic factors may then be translated into neurotrophic support of the central nervous system. We propose that artificial saliva used to treat xerostomia should also contain suitable neurotrophic factors to prevent loss of taste sensation and possibly also prevent neuropathy of the central and peripheral nervous systems.