Distribution, immunohistochemical characteristics and nerve pathways of primary sensory neurons supplying the porcine vas deferens

Abstract

The present study investigated: (1) the distribution and chemical coding of primary sensory neurons supplying the vas deferens in juvenile pigs by the use of retrograde tracing combined with double-labelling immunofluorescence, (2) nerve pathways from dorsal root ganglia (DRG) to the vas deferens by means of denervation procedures involving transection of the hypogastric or pelvic nerve combined with a retrograde tracing method, and (3) possible interactions of the substance P (SP)/calcitonin gene-related peptide (CGRP)-immunoreactive varicose nerve fibres on vas deferens projecting neurons (VDPN) in the anterior pelvic ganglion (APG). The vast majority of VDPN were found mainly in the lumbar L2, L3 and sacral S2, S3 pairs of DRG and showed a clear ipsilaterally organized projection pattern. Immunohistochemistry revealed that most of these neurons contained SP and/or CGRP, occasionally coexpressed with galanin. Interestingly, pronounced differences in the expression of SP and/or CGRP were observed between the lumbar and sacral VDPN in that most of the lumbar but less than half of the sacral neurons stained for these peptides. Denervation experiments showed that the neurons located within the lumbar DRG project through the ipsilateral hypogastric nerve, whereas those found within the sacral DRG send their processes through the ipsilateral and contralateral pelvic nerve. In the nerve-lesioned animals, especially in those with the hypogastric nerve cut, a dramatic reduction in the number of SP and/or CGRP-containing nerve terminals surrounding the efferent VDPN within the APG was observed. This study has disclosed the distribution and, for the first time, chemical coding and nerve pathways of vas deferens-projecting primary sensory neurons in a mammalian species, the pig. The results obtained also provide some novel information about the possible morphological and functional relationship between vas deferens-projecting primary sensory and pelvic efferent nerve cells.

Striated Perineal Muscles: Location of Autonomic, Sensory, and Somatic Neurons Projecting to the Male Pig Bulbospongiosus Muscle

“…A bilateral positivity in SGs has been observed in some genital organs, such as the vas deferens of the rat (Kolbeck and Steers, 1993) and of the pig (Kaleczyc et al, 2002) and the retractor penis muscle of the pig (Panu et al, 2003). The sacral extension of marked SGs found in this study confirms that also in the pig the afferent fibres from BSM travel along the pudendal nerve.…”

“…6 red and blue lines). Numerous morphological and physiological studies have revealed that CMGs and PGs receive and integrate nervous inputs originating from different sources, including sympathetic preganglionic, viscerofugal enteric and spinal sensory neurons (Simmons, 1985;Keast, 1999;Majewski, 1999;Bossowska, 2002;Kaleczyc et al, 2002). In particular, these spinal afferents may influence the activity of postganglionic autonomic neurons both directly (through their collaterals within the CMGs or PGs) and indirectly (through axonal collaterals forming synaptic contacts with either preganglionic autonomic neurons in the intermedio-lateral nucleus or interneurons within the dorsal horn) (Keast, 1999;Majewski, 1999;Bossowska, 2002;Kaleczyc et al, 2002).…”

“…Since the different neurons dimensions may imply different functions (Wasowicz et al, 1998;Bossowska, 2002;Kaleczyc et al, 2002), further research, with more suitable neuronal markers, such as horseradish peroxidase, will be carried out to define the precise dimensions of BSM-projecting neurons. Moreover, immunohistochemical techniques will be used to define the neurochemical content of these cells.…”

“…The research was carried out on the pig, an important zootechnical animal and an interesting model in biomedical (Dodds, 1982;Swindle et al, 1992;Crissinger et al, 1994) and neuro-anatomical studies (Merighi et al, 1990;Timmermans et al, 1993;Kaleczyc et al, 1995Kaleczyc et al, , 1999Kaleczyc et al, , 2002Kaleczyc, 1998;Majewski et al, 1999;Panu et al, 2001Panu et al, , 2003Botti et al, 2006).…”

Sensory and Autonomic Neurons Project Both to the Smooth Retractor Penis and to the Striated Bulbospongiosus Muscles. Neurochemical Features of the Sympathetic Subset

“…For several years, our research group has been studying the site and immunohistochemical characteristics of the peripheral and/or central neurons related to smooth and striated muscles of the genital organs of the male pig, that is frequently used as a model in biomedical research (Dodds, 1982;Swindle et al, 1992;Crissinger et al, 1994), including neuroanatomical studies (Merighi et al, 1990;Majewski and Heym, 1992;Timmermans et al, 1993;Panu et al, 2001;Bossowska, 2002;Kaleczyc et al, 2002;Panu et al, 2003;Botti et al, 2006aBotti et al, ,b, 2009. Our localization studies (Bo Minelli et al, 2000Botti et al, 2003;Panu et al, 2003;Botti et al, 2006bBotti et al, , 2009) have constantly documented that the peripheral sensory and autonomic neurons, innervating the aforesaid muscles, are rather numerous and located in very similar peripheral sites.…”