A research team led by Prof. WANG Liping and Prof. WANG Feng at the Shenzhen Institute of Advanced Technology (SIAT) of the Chinese Academy of Sciences, has successful mapped the neural network innervating the kidneys in male and female mice, providing insights into the brain's role in coordinating multiple organs to maintain the body's internal balance. The study was published in Neuroscience Bulletin.

The kidneys, recognized as the key excretory organs, filter about 24% of the daily cardiac output, maintaining water-salt balance and regulating blood pressure. Fluctuations in mood, by causing the narrowing of blood vessels and by stimulating the release of renin through renal nerves, can result in sudden increase in blood pressure. 

Clinical observations have established a connection between kidney diseases and sleep disturbances, cognitive impairments, and emotional issues. It is well-known that the brain and kidneys are extensively interconnected in terms of physiology, but the specific neural pathways connecting the two—especially with regard to sexual differences—have remained somewhat unclear.

In this study, the researchers, using neuro-philic pseudorabies virus as a retrograde tracer, identified the brain nuclei linked to either the left or right kidney, as well as to the kidney's cortex or medulla in both male and female mice. 34 kidney-related brain regions were identified and quantified, most of which were located subcortically, particularly in the hypothalamus, pons, and medulla—collectively referred to as the vital center.

Importantly, the researchers revealed an asymmetrical distribution of neurons in five key brain regions between left and right kidney networks. They also disclosed sexual differences in the density of renal innervation within the lateral hypothalamus. Furthermore, the analysis of the central kidney-related networks between the kidney cortex and medulla revealed variations in connection intensity, especially in male mice.

“Our study provides a detailed map of kidney-brain connectivity, which considers the neural innervation of different functional and structural components of the kidney, along with the impact of sex,” said Prof. WANG Feng.

For the broader implications, the findings suggest that various visceral organs might share a similar central network as seen in the kidneys, highlighting the brain's integrative role in maintaining homeostasis across different organs and tissues.

This study deepens the understanding of renal functions in various contexts.