CNS innervation of the urinary bladder demonstrated by immunohistochemical study for c-fos and pseudorabies virus

Abstract

The aim of the present study is to verify the functional and anatomical neural pathways which innervate the urinary bladder in the central nervous system of the rat. To identify the functional neural pathway, the urinary bladder was stimulated by infusing formalin for 2 h. Then, brain and spinal cord were dissected out and immunohistochemistry was done by using anti-c-fos antibody. Many c-fos immunoreactive (IR) neurons were identified in the telencephalic cortical areas and in several brainstem nuclei, which are known mostly to be related with urinary bladder. In the spinal cord, a number of c-fos IR neurons were found in the lamina I, IIo, dorsal gray commissure, sacral parasympathetic nucleus. To identify the anatomical neural pathway of the urinary bladder, Pseudorabies virus (PRV) was injected into the wall of urinary bladder and was identified with anti-PRV by using immunohistochemistry. Most PRV labeled neurons were found where c-fos IR neurons were identified and few of them were also in the areas where c-fos IR neurons were not found, e.g., prefrontal cortex, agranular insular cortex, and subfornical organ. In the spinal cord, PRV labeled cells were found all over the gray matter. The present study presents morphological evidence demonstrating the supraspinal areas are related with the neural control of the urinary bladder and most functional neural pathway of the urinary bladder is well consistent with the anatomical neural pathway except in some telencephalic cortical areas.

Regional Targeting of Bladder and Urethra Afferents in the Lumbosacral Spinal Cord of Male and Female Rats: A Multiscale Analysis

“…We did not perform immunohistochemical characterization of LUT afferents within spinal cord regions but did observe a sparse but consistent innervation of superficial laminae in the dorsal horn, as expected for nociceptive projections and documented by electron microscopy ( Park et al, 2019 ). This innervation was sparse in comparison to several other regions but is not the only site of LUT nociceptive signaling in the L6-S1 cord ( Cruz et al, 1996 ; Park et al, 1997 ; Lagos and Ballejo, 2004 ). Moreover, many sensory projections in the medial collateral pathway of the L6-S1 cord express GFRα3, a feature of many TRPV1-positive nociceptors innervating the bladder ( Forrest and Keast, 2008 ; Forrest et al, 2013 ).…”

“…Continuous cystometry evokes immediate early gene expression in putative local interneurons within the SDCom (Cruz et al, 1994;Wiedmann et al, 2020), which could be initiated by both bladder and urethra afferents during the voiding cycle. This region also contains interneurons involved in urethral rhabdosphincter regulation, identified following transsynaptic tracing (Nadelhaft and Vera, 1996;Park et al, 1997;Vizzard et al, 1995).…”

“…Continuous cystometry evokes immediate early gene expression in putative local interneurons within the SDCom ( Cruz et al, 1994 ; Wiedmann et al, 2021 ), which could be initiated by both bladder and urethra afferents during the voiding cycle. This region also contains interneurons involved in urethral rhabdosphincter regulation, identified following transsynaptic tracing ( Vizzard et al, 1995 ; Nadelhaft and Vera, 1996 ; Park et al, 1997 ). Additional roles of this region are indicated by immediate early gene mapping and transsynaptic labeling of motor pathways, which have identified responses to nociceptive stimuli and interneurons related to urogenital reflexes; these predominate in L6 ( Honda, 1985 ; Birder and de Groat, 1992 ; Chinapen et al, 1992 ; Berkley et al, 1993 ; Vizzard, 2000 ; Marson et al, 2003 ; Marson and Murphy, 2006 ; Dobberfuhl et al, 2014 ).…”

Effects of Herpes Simplex Virus Vector–Mediated Enkephalin Gene Therapy on Bladder Overactivity and Nociception

“…4A and B). It has been reported that the most remarkable change in c-fos expression after bladder irritation occur in the DCM and then SPN regions of the L6 spinal cord in the rat (Birder and de Groat, 1992;Cruz et al, 1994Cruz et al, , 1996Park et al, 1997). Birder and de Groat also reported that the number of c-fos-positive cells in the DCM was related to activation of both pelvic and pudendal nerves and that the number of c-fos-positive cells in the SPN and MDH corresponds to pelvic nerve and pudendal nerve activation, respectively.…”