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Author Rice, Cory D. ♦ Lois, James H. ♦ Kerman, Ilan A. ♦ Yates, Bill J.
Source PubMed Central
Content type Text
File Format PDF
Date Created 2009-05-10
Language English
Difficulty Level Medium
Subject Domain (in DDC) Technology ♦ Medicine & health
Subject Keyword Developmental Biology ♦ Neuroscience(all) ♦ Molecular Biology ♦ Clinical Neurology
Abstract Although a considerable body of literature indicates that serotoninergic neurons affect diaphragm activity both through direct inputs to phrenic motoneurons and multisynaptic connections involving the brainstem respiratory groups, the locations of the serotoninergic neurons that modulate breathing have not been well defined. The present study identified these neurons in cats by combining the transneuronal retrograde transport of rabies virus from the diaphragm with the immunohistochemical detection of the N-terminal region of tryptophan hydroxylase-2 (TPH2), the brain-specific isoform of the enzyme responsible for the initial and rate-limiting step in serotonin synthesis. TPH2-immunopositive neurons were present in the midline raphe nuclei, formed a column in the ventrolateral medulla near the lateral reticular nucleus, and were spread across the dorsal portion of the pons just below the fourth ventricle. In most animals, only a small fraction of neurons (typically < 20%) labeled for TPH2 in each of the medullary raphe nuclei and the medullary ventrolateral column were infected with rabies virus. However, the percentage of medullary neurons dual-labeled for both rabies and TPH2 was much higher in animals with very advanced infections where virus had spread transneuronally through many synapses. Furthermore, in all cases, TPH2-immunopositive neurons that were infected by rabies virus were significantly less prevalent in the pons than the medulla. These findings suggest that although serotoninergic neurons with direct influences on diaphragm activity are widely scattered in the brainstem, the majority of these neurons are located in the medulla. Many nonserotoninergic neurons in the raphe nuclei were also infected with rabies virus, indicating that midline cells utilizing multiple neurotransmitters participate in the control of breathing.
ISSN 00068993
Age Range above 22 year
Educational Use Research
Interactivity Type Expositive
Education Level UG and PG
Learning Resource Type Article
Publisher Date 2009-07-01
e-ISSN 18726240
Journal Brain research
Volume Number 1279
Page Count 11
Starting Page 71
Ending Page 81


Source: PubMed Central