Premium
Developmental changes in breathing pattern and neuronal morphology in the respiratory centers of the neonatal rat
Author(s) -
Williams Paul,
Murray Samuel,
Wilson Christopher
Publication year - 2016
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.30.1_supplement.996.1
Subject(s) - brainstem , respiratory rate , breathing , respiratory system , biology , ventilation (architecture) , vibratome , neuroscience , nucleus , pons , central nervous system , anatomy , medicine , endocrinology , heart rate , mechanical engineering , blood pressure , engineering
The autonomic brainstem generates and controls breathing rhythm. Several studies have shown that control of breathing changes during early development. However, little is known about changes in the morphology of neurons in the respiratory regions of the brainstem during early development and how these morphological changes correlate with changes in breathing pattern. We hypothesize that developmental changes in morphology of neurons in the preBötzinger Complex (pBC), the nucleus tractus solitarii (nTS), and the hypoglossal motor nucleus (XII) are correlated with changes in breathing pattern. To test this hypothesis, we used Golgi‐Cox staining, a high‐resolution bright‐field stain, to examine the somata and dendritic tree of developing neurons in pBC, nTS, and XII. Before staining, we used whole‐body plethysmography to assess the breathing pattern of animals from postnatal day 1 (P1) through postnatal day 21 (P21). We quantified changes in tidal volume, flow, and minute ventilation. We also used automated detection software to quantify breathing rate (breaths/minute), inspiratory and expiratory times, number of breathing pauses (apneas) and variability of breathing pattern (Sample and Shannon entropy). We then removed the brain from each animal in our sample cohort, sectioned the brain using a vibratome, and performed Golgi‐Cox staining to examine dendritic morphology of the neurons in the pBC, nTS, and XII. The number of apneas per minute and breathing rate increased linearly to P10. Sample and Shannon Entropy, measures of signal complexity, decreased from P1 to P10 and plateaued through to P21. The dendritic arbor of developing neurons becomes more complex from P1 through P10 with increased branching and spine numbers which correlated with the changes in breathing pattern.