Prenatal development of transient receptor potential vanilloid 1-expressing primary sensory projections to sacral autonomic preganglionic neurons.
The visceral reflexes of the pelvic organs are mediated by connections between primary afferents innervating the pelvic organs and parasympathetic preganglionic neurons in the intermediolateral column of the sacral spinal cord. The present immunohistochemical study revealed many varicosities expressing transient receptor potential vanilloid 1 (TRPV1) that were closely apposed to the preganglionic neuronal perikarya at embryonic day 16 in mice. Many, but not all, varicosities expressing TRPV1 in the intermediolateral column were also immunopositive for calcitonin gene-related peptide. In contrast, no nerve fibers expressing TRPV1 projected to the sympathetic preganglionic cell column in the lumbar spinal cord in prenatal stages. The results of the present study raised the possibility that the primary afferents transmit signals elicited by the activation of TRPV1 receptors to the sacral parasympathetic preganglionic neurons. Thus, the functional circuit for pelvic spinal reflexes, such as micturition induced by urine influx, might develop in the prenatal stages in mice.
Funakoshi
Kengo
K
Department of Neuroanatomy, Yokohama City University School of Medicine, 3-9 Fukuura, Yokohama, Japan. funako@med.yokohama-cu.ac.jp
Nakano
Masato
M
Atobe
Yoshitoshi
Y
Kadota
Tetsuo
T
Goris
Richard C
RC
D000344:Afferent Pathways / Q000196:embryology / Q000502:physiology; D000818:Animals; D001339:Autonomic Fibers, Preganglionic / Q000502:physiology*; D015740:Calcitonin Gene-Related Peptide / Q000378:metabolism; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D051379:Mice; D008813:Mice, Inbred ICR; D009475:Neurons, Afferent / Q000378:metabolism / Q000502:physiology*; D019001:Nitric Oxide Synthase / Q000378:metabolism; D012018:Reflex; D012445:Sacrococcygeal Region; D013116:Spinal Cord / Q000166:cytology / Q000196:embryology* / Q000378:metabolism; D050916:TRPV Cation Channels / Q000096:biosynthesis*
D050916:TRPV Cation Channels; C493921:TRPV1 protein, mouse; D019001:Nitric Oxide Synthase; D015740:Calcitonin Gene-Related Peptide