Localization of renal sensory neurons using the fluorescent dye technique

Area of Science:

• Neuroscience
• Renal Physiology

Background:

• Renal sensory neurons play a crucial role in regulating kidney function and pain perception.
• Understanding the central projections of these neurons is essential for deciphering pain pathways and developing targeted therapies.

Purpose of the Study:

• To determine the precise location of renal sensory neuron cell bodies within the rat central nervous system.
• To investigate potential sex-based differences in the distribution of these neuronal cell bodies.

Main Methods:

• Adult male and female rats underwent unilateral injections of fluorescent tracers (True Blue or Fast Blue) into the renal parenchyma.
• Retrogradely labeled cell bodies in dorsal root ganglia (DRG) were subsequently identified and quantified using fluorescence microscopy.

Main Results:

• Labeling of renal sensory neuron cell bodies was consistently observed in the T6-L2DRG segments, ipsilateral to the injected kidney.
• No significant differences in labeling patterns were detected between male and female rats.
• Injections into the right kidney resulted in slightly higher labeling in more dorsal DRG compared to left kidney injections.

Conclusions:

• The T6-L2DRG segments represent the primary central location for rat renal sensory neuron cell bodies.
• Renal sensory innervation does not appear to differ significantly between sexes in rats.
• A subtle topographical organization may exist, with right-sided renal input potentially targeting slightly more dorsal DRG levels.