Abstract
A large number of viable genetically modified mice are now available that can be used to elucidate the role of the deleted, mutated, or overexpressed genesfor regulaton of physiological functions. To assess functional changes induced by genetic modification, many physiological parameters have been studied. However, few attempts have been made in mice to measure sympathetic nerve activity which play a critical role for regulation of many physiological functions including cardiovascular control, energy metabolism, and the immune system. In the present study we have established the methods for measuring renal sympathetic nerve activity in freely moving mice. The left kidney was exposed retroperitoneally through a left flank incisionand the sympathetic nerves running on or beside the renal artery were identified with aid of a dissecting microscope. The two tips of the stainless steel electrodes were attached to the nerve. The renal sympathetic nerve activitywas recorded successfully without contamination by external noise such as that from the electrocardiogram and/or electromyogram. Nerve recoding continued over 3-4 days after surgery. .The renal sympathetic nerve activity was increased by ~240% during movement relative to the quiet awake state and was suppressed completely by administration of hexamethonium. Thus, this method for measurement of the RSNA could be useful for study of sympathetic nerve activity in genetically modified mice. [Jpn J Physiol 54 Suppl:S203 (2004)]
