title: The spinal segmental and preganglionic projections from the brainstem in relation to the chicken cloaca.
abstract: Descending projections from the brainstem to the sympathetic and parasympathetic regions of the chicken spinal cord were investigated by means of the WGA-HRP method. The segmental and preganglionic injections of WGA-HRP were made into spinal segments 20-23 and 30-33 which were sympathetically and parasympathetically related to the cloaca, respectively. After injections of a large amount of WGA-HRP into each level of segments 20-23 and 30-33, the labeled SP-neurons (segmental projection neurons) were distributed mainly in the ventral half of the medulla in both cases. The distribution of these labeled neurons extended mainly to the central (20-23 segmental injections) and the lateral (30-33 segmental injections) tegmental regions of the pons. In the mesencephalon, some SP-neurons were found in the dorsomedial reticular formation and the dorsal midline area, in addition to the Ru in both cases. By iontophoretic microinjections of WGA-HRP into the preganglionic regions of these segments, the labeled preganglionic projection neurons (PP-neurons) were found in the ventromedial part of the medulla. Both distributions of the labeled PP-neurons projecting to the sympathetic and parasympathetic regions were similar in the medulla. In the pons, although the sympathetic PP-neurons were found in the ventromedial pontine tegmentum, most of the parasympathetic PP-neurons were found in the dorsolateral tegmentum, e.g., the LoC-SC region. In the mesencephalon, a few sympathetic PP-neurons were found in the midline area ventromedial to the EW, but no parasympathetic PP-neurons were observed in the mesencephalon.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Laboratory of Animal Morphology and Function, School of Agriculture, Nagoya University, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Naito
authors.forename: Y
authors.initials: Y
authors.lastname: Ohmori
authors.forename: N
authors.initials: N
authors.lastname: Kimura
authors.forename: M
authors.initials: M
authors.lastname: Shiraishi
authors.forename: T
authors.initials: T
authors.lastname: Watanabe
mesh_terms: D000818:Animals; D001339:Autonomic Fibers, Preganglionic / Q000502:physiology*; D001933:Brain Stem / Q000502:physiology*; D002645:Chickens / Q000502:physiology*; D002988:Cloaca / Q000294:innervation*; D005260:Female; D005726:Ganglia, Parasympathetic / Q000166:cytology / Q000502:physiology; D005728:Ganglia, Sympathetic / Q000166:cytology / Q000502:physiology; D006735:Horseradish Peroxidase; D009434:Neural Pathways / Q000502:physiology; D013116:Spinal Cord / Q000502:physiology*; D018998:Wheat Germ Agglutinin-Horseradish Peroxidase Conjugate; D014909:Wheat Germ Agglutinins
chemical_list: D018998:Wheat Germ Agglutinin-Horseradish Peroxidase Conjugate; D014909:Wheat Germ Agglutinins; D006735:Horseradish Peroxidase