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BDNF protein exhibits a circadian rhythm in the hypoglossal, but not phrenic, motor nucleus
Author(s) -
Guenther Courtney Helena,
DaleNagle Erica A.,
Mitchell Gordon S.
Publication year - 2008
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.22.1_supplement.1232.3
Subject(s) - circadian rhythm , hypoglossal nucleus , suprachiasmatic nucleus , neuroscience , intermittent hypoxia , medicine , endocrinology , biology , anesthesia , nucleus , obstructive sleep apnea
BDNF is a key molecule in respiratory plasticity, particularly long‐term facilitation (LTF) following intermittent hypoxia (Baker‐Herman et. al ., 2004). LTF is prominent in upper airway motor activity and may help to maintain upper airway patency during sleep, preventing the recurrence of obstructive apneas (Mahamed and Mitchell, 2007). Although BDNF exhibits a circadian rhythm within the suprachiasmatic nucleus (Liang et. al., 1998), it is unknown if BDNF exhibits circadian rhythms in regions of interest to respiratory control, such as respiratory motor nuclei. To test the hypothesis that BDNF protein exhibits circadian rhythms in the phrenic and hypoglossal (XII) motor nuclei, tissues were sampled from ventral cervical spinal segments (C 3 –C 5 ) and XII nucleus in Sprague‐Dawley rats, (light/dark cycle: 6AM/6PM), at 6, 12, 18, and 24 hours. Results: BDNF protein exhibited a circadian cycle in the XII, but not phrenic, motor nucleus; BDNF protein levels were lower during the subjective night (12PM–5PM). At its lowest point (5PM–7PM), BDNF was 66 ± 11.5% (S.E.M.) lower than at 5AM‐7AM (p<0.05). The circadian BDNF rhythm may have important implications for the expression of respiratory plasticity in motor output, particularly to muscles controlling upper airway resistance. Thus, BDNF rhythms may contribute to the pattern of obstructive sleep apnea (Supported by NIH HL 80209).