Related Experiment Video
Updated: Jun 6, 2026

Dissection of Pelvic Autonomic Ganglia and Associated Nerves in Male and Female Rats
Published on: March 7, 2020
[Selective innervation of sacral anterior rootlets to micturition and erection function in rats]
Wen-ting Wang1, Mou-wang Zhou, Hong-shi Huang
1Department of Rehabilitation Medicine, Peking University Third Hospital, Beijing 100191, China.
Objective:
To investigate the selective innervation of sacral anterior rootlets to micturition and erection function in SD rats.
Methods:
Forty male SD rats of clean grade, aged 6 weeks old, were selected. Ten rats received a retrograde nerve tract tracing study. Thirty rats were chosen for an electro-physiological study. The L6, S1 spinal cord segment anterior rootlets of anesthetic rats were electrostimulated respectively. The intravesical pressure, urethral perfusion pressure and intracavernous pressure were recorded simultaneously and innervation effectiveness was analyzed.
Results:
CB-HRP labeled neurons were observed mainly in L6 and S1 spinal cords. When some anterior rootlets of L6 and S1 were electrostimulated, the intravesical pressure rose gradually, but the urethral perfusion pressure and the intracavernous pressure curve changed slightly; when other rootlets of the same anterior root were stimulated, the urethral perfusion pressure could reach the peak; while others were stimulated, the intracavernous pressure rose quickly, but there were no great changes in intravesical pressure and urethral perfusion pressure. Some other rootlets might lead to the simultaneous changes of 2 or 3 above-mentioned pressures.
Conclusion:
The innervations of L6 and S1 anterior rootlets to rats' bladder detrusor, external urethral sphincter and penile cavernous body are significantly distinct. Different rootlets may be distinguished by microanatomy and electrostimulation.
Related Concept Videos
The Micturition Reflex
The process begins with bladder filling, where the bladder wall stretches as urine accumulates. This stretching activates the urine storage reflex, mediated by the sacral spinal segments and the pontine storage center. Efferent sympathetic impulses stimulate the detrusor muscle to relax and the internal urethral sphincter to contract, facilitating urine...
Male Sexual Response: Erection & Ejaculation
The blood filling the erectile tissues compresses the veins, which helps to prevent blood from leaving...
Anatomy of the Genitourinary System II: Bladder and Urethra
Urinary Bladder
In males, the bladder is situated in front of the rectum, while in females, it is positioned anterior to the vagina and uterus. The bladder floor contains an inverted triangular area called the trigone, defined by the two ureteric...

