Translational physiology and SND recordings in humans and rats: a glimpse of the recent past with an eye on the future.

The sympathetic nervous system (SNS) plays an important role in cardiovascular function, and based on the critical mechanistic relationship between altered sympathetic neural mechanisms and cardiovascular disease, it is important that the autonomic research community identifies deficiencies in the translational exchange of information and strives for a more thorough understanding of the translational significance of findings from studies involving sympathetic nerve discharge (SND) regulation in human and animal subjects. The present review assesses the state of the literature regarding studies that have used direct recordings of SND during the past three decades in humans and rats, focusing on; 1) identifying the number of studies reporting SND recordings in humans and rats, 2) briefly describing the translational exchange of SND regulation information from these studies, 3) contrasting the number of studies completed in anesthetized and conscious rats, and 4) assessing the prevalence of long-term SND recording studies in conscious rats. The majority of SND recordings in rats have been completed using anesthetized preparations, although a substantial number of studies have been completed in conscious rats. However, few studies have completed long-term (>5 days) SND recordings in freely-behaving rats, and even fewer studies have used experimental preparations that combine long-term nerve recordings with the capacity for completing central neural microinjections, or have been completed in animal models of cardiovascular disease. The wide-spread implementation of long-term SND recordings in rodent models of cardiovascular disease would be expected to enhance the translational exchange of clinically-relevant information between animals and humans.