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Role of locus coeruleus neurons in central O 2 chemoreflex during development in Rana catesbeiana
Author(s) -
Fournier Stephanie,
Kinkead Richard
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.5.a559
Subject(s) - locus coeruleus , brainstem , rana , bullfrog , amphibian , biology , endocrinology , medicine , hypoxia (environmental) , central nervous system , tyrosine hydroxylase , neuroscience , chemistry , dopamine , ecology , oxygen , organic chemistry
In bullfrog, brainstem hypoxia elicits stage‐dependent changes in fictive lung ventilation in vitro . Noradrenergic neurons seem necessary to this reflex because α 1 ‐adrenoceptor inactivation prevents this response. Since we know that locus coeruleus (LC) contains a wide concentration of noradrenergic neurons in amphibian, we used an in vitro brainstem preparation from Rana catesbeiana to test the hypothesis that LC neurons are necessary to the fictive lung ventilation response to central hypoxia. We compared the effects of brainstem transection prior nerve VII from pre‐metamorphic tadpoles and adults. Transection before hypoxia prevents the decrease in lung burst frequency in adult frogs and the increase in pre‐metamorphic group from stage XII but not from stages VIII–IX. Immunohistochemistry for tyrosine hydroxylase (TH) showed that in the LC, adults have more TH‐positive neurons than in pre‐metamorphic stages. We conclude that noradrenergic neurons from the LC area are necessary for the manifestation of the central O 2 chemoreflex in Rana . However, these neurons undergo important reorganisation during development. Funded by the Natural Sciences and Engineering Council of Canada.