Caudal ventrolateral medullary projections to the nucleus of the solitary tract in the cat.
The projections of neurons, in and around the A1 noradrenergic cell group of the caudal ventrolateral medulla (VLM), to nucleus of the solitary tract (NTS) were studied in the cat using the anterograde transport of Phaseolus vulgaris leucoagglutinin (PHA-L). PHA-L was micro-iontophoresed into the region of the A1 noradrenergic cell group and after a 7-17 day survival period animals were sacrificed and brainstem sections were processed for PHA-L or tyrosine hydroxylase (TH) immunoreactivity. PHA-L injections within the region of the A1 cell group resulted in labelled fibers with their presumptive terminal boutons primarily in the ipsilateral commissural and medial subnuclei of NTS. A light projection to the ipsilateral parvocellular lateral and ventrolateral subnuclei of the NTS complex was also observed. These data demonstrate that neurons in the region of the A1 noradrenergic cell group project to regions of NTS that receive cardiovascular afferent inputs and suggest that VLM may influence the activity of neurons in NTS involved in the reflex regulation of the circulation.
Roder
S
S
Department of Physiology, University of Western Ontario, London, Canada.
Ciriello
J
J
D000818:Animals; D001370:Axonal Transport; D002415:Cats; D007839:Functional Laterality; D008526:Medulla Oblongata / Q000033:anatomy & histology / Q000502:physiology*; D009412:Nerve Fibers / Q000502:physiology / Q000648:ultrastructure; D009474:Neurons / Q000166:cytology / Q000502:physiology*; D010835:Phytohemagglutinins; D014446:Tyrosine 3-Monooxygenase / Q000032:analysis
D010835:Phytohemagglutinins; C100156:leukoagglutinins, plants; D014446:Tyrosine 3-Monooxygenase