Brainstem connections of the rat ventral respiratory subgroups: afferent projections

J Auton Nerv Syst. 1993 Feb;42(2):99-118. doi: 10.1016/0165-1838(93)90042-s.


Propriobulbar neurons having axonal projections to the Ventral Respiratory Group (VRG) were retrogradely labeled after discrete injections of Fast blue into one of the three physiologically identified subdivisions (Bötzinger Complex, rostral inspiratory and caudal expiratory regions). Neurons that project to these regions were found throughout the rostrocaudal extent of the medulla and the pons in a variety of areas known to have cardio-respiratory function. Labeled somata were located within the nuclei of the solitary tract (commissural, intermediate and ventrolateral), other subdivisions of VRG, parabrachial nuclei (medial, dorsolateral and central lateral), Kölliker-Fuse nucleus, retrotrapezoid nucleus, lateral paragigantocellular nucleus and lateral tegmental field of the pons. Within the nuclei of the solitary tract and the Kölliker-Fuse nucleus, there was a topographical organization with respect to the three subdivisions of the VRG.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Afferent Pathways / physiology
  • Amidines
  • Animals
  • Axons / physiology
  • Brain Mapping*
  • Brain Stem / cytology
  • Brain Stem / physiology*
  • Brain Stem / ultrastructure
  • Fluorescent Dyes
  • Neurons / physiology
  • Rats
  • Rats, Wistar
  • Respiratory System / innervation*
  • Synaptic Transmission*


  • Amidines
  • Fluorescent Dyes
  • diamidino compound 253-50