Vagal afferents from the uterus and cervix provide direct connections to the brainstem.
Animals; Brain Stem/*anatomy & histology; Cervix Uteri/*innervation; Estrogen/metabolism; Female; Immunohistochemistry; Neurons/cytology/metabolism; Rats; Receptors; Sprague-Dawley; Uterus/*innervation; Vagus Nerve/*anatomy & histology/metabolism
Previous anatomical studies demonstrated vagal innervation to the ovary and distal colon and suggested the vagus nerve has uterine inputs. Recent behavioral and physiological evidence indicated that the vagus nerves conduct sensory information from the uterus to the brainstem. The present study was undertaken to identify vagal sensory connections to the uterus. Retrograde tracers, Fluorogold and pseudorabies virus were injected into the uterus and cervix. DiI, an anterograde tracer, was injected into the nodose ganglia. Neurectomies involving the pelvic, hypogastric, ovarian and abdominal vagus nerves were performed, and then uterine whole-mounts examined for sensory nerves containing calcitonin gene-related peptide. Nodose ganglia and caudal brainstem sections were examined for the presence of estrogen receptor-containing neurons in "vagal locales." Labeling of uterine-related neurons in the nodose ganglia (Fluorogold and pseudorabies virus) and in the brainstem nuclei (pseudorabies virus) was obtained. DiI-labeled nerve fibers occurred near uterine horn and uterine cervical blood vessels, in the myometrium, and in paracervical ganglia. Rats with vagal, pelvic, hypogastric and ovarian neurectomies exhibited a marked decrease in calcitonin gene-related peptide-immunoreactive nerves in the uterus relative to rats with pelvic, hypogastric, and ovarian neurectomies with intact vagus nerves. Neurons in the nodose ganglia and nucleus tractus solitarius were immunoreactive for estrogen receptors. These results demonstrated: (1) the vagus nerves serve as connections between the uterus and CNS, (2) the nodose ganglia contain uterine-related vagal afferent neuron cell bodies, and (3) neurons in vagal locales contain estrogen receptors.
Collins J J; Lin C E; Berthoud H R; Papka R E
Cell and tissue research
1999
1999-01
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1007/s004410051211" target="_blank" rel="noreferrer noopener">10.1007/s004410051211</a>
Distribution of tyrosine hydroxylase, serotonin, and leu-enkephalin immunoreactive cells in the brainstem of a shark, Squalus acanthias.
Animals; Brain Mapping; Brain Stem/*anatomy & histology; Diencephalon/anatomy & histology; Dogfish/*anatomy & histology; Enkephalin; Immunoenzyme Techniques; Leucine/*analysis; Mesencephalon/anatomy & histology; Nerve Fibers/ultrastructure; Neurons/ultrastructure; Rhombencephalon/anatomy & histology; Serotonin/*analysis; Spinal Cord/anatomy & histology; Tyrosine 3-Monooxygenase/*analysis
The central nervous system location of neurochemicals that are widely distributed among extant animals may give us clues to changes that occurred in the brains of these animals during evolution. We have been studying the brains of cartilaginous fishes, a heterogeneous group whose central nervous system varies considerably. Squalus acanthias, the spiny dogfish shark, was chosen to represent the squalomorphs, a group of living sharks known to possess many primitive characters. The distribution of tyrosine hydroxylase (TH+), serotonin (5-HT+), and leu-enkephalin (LENK+) positive cells within the brainstem of Squalus was determined by use of antibodies to these substances. All the major raphe groups described for mammals were found in Squalus. The 5-HT+ cells in raphe nuclei were more uniformly distributed in Squalus than in Heterodontus, the horn shark. Other nuclei that were 5-HT+ and LENK+, and that have been identified in mammals, included reticularis paragigantocellularis lateralis, a B9 cell group, and reticularis magnocellularis. The postcommissural nucleus and pretectal area contained 5-HT+ and LENK+ cells. These cells have been described in a holocephalian, in teleosts, and in reptiles but not in other elasmobranchs or in mammals. Cells that were TH+ were located in prominent A1/A2, A6 (locus coeruleus), A9 (substantia nigra), and A10 (ventral tegmental area) cell groups, and in a very small A5 group. We conclude that the variation in chondrichthian brainstems exceeds that in mammals, and we suggest that this variation is related to life-style and the long evolutionary history of these fishes.
Stuesse S L; Cruce W L
Brain, behavior and evolution
1992
1992
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1159/000114106" target="_blank" rel="noreferrer noopener">10.1159/000114106</a>