Water channel proteins in the peripheral nervous system in health and disease.

The expression and function of aquaporins (AQPs) in the peripheral nervous system is a relatively under-investigated subject. Since the original description of AQP1 mRNA expression in the trigeminal ganglion in 2004, there has been significant progress in describing the expression, regulation and function of AQPs in the peripheral nervous system. Three out of the 13 mammalian AQPs (AQP1, AQP2 and AQP4) have been localized to neurons or glial cells in trigeminal ganglia, periodontal Ruffini endings, dorsal root ganglia and the enteric nervous system. Functional studies using knockout mice have suggested the involvement of AQP1 in peripheral pain perception. This review discusses current progress in this field and the possible involvement of AQPs in peripheral neuropathies.