scholarly journals Role of TrkB during the postnatal development of the rat carotid body

2015 ◽  
Vol 219 ◽  
pp. 18-24 ◽  
Author(s):  
Ryan W. Bavis ◽  
Halward J. Blegen ◽  
Sarah Logan ◽  
Sarah C. Fallon ◽  
Amy B. McDonough
Keyword(s):  
Postnatal Development ◽  
Carotid Body

scholarly journals Divergent postnatal development of the carotid body in DBA/2J and A/J strains of mice

2012 ◽  
Vol 112 (3) ◽  
pp. 490-500 ◽  
Author(s):  
Eric W. Kostuk ◽  
Alexander Balbir ◽  
Koichi Fujii ◽  
Akiko Fujioka ◽  
Luis E. Pichard ◽  
...  
Keyword(s):  
Gene Expression ◽  
Postnatal Development ◽  
Carotid Body ◽  
Postnatal Period ◽  
Body Volume ◽  
Morphological Development ◽  
Distinctive Morphology ◽  
The Difference ◽  
Cervical Ganglia

We have previously shown that the adult DBA/2J and A/J strains of mice differ in carotid body volume and morphology. The question has arisen whether these differences develop during the prenatal or postnatal period. Investigating morphological development of the carotid body and contributing genes in these mice can provide further understanding of the appropriate formation of the carotid body. We examined the carotid body of these mice from 1 day to 4 wk old for differences in volume, morphology, and gene expression of Gdnf family, Dlx2, Msx2, and Phox2b. The two strains showed divergent morphology starting at 1 wk old. The volume of the carotid body increased from 1 wk up to 2 wk old to the level of 4 wk old in the DBA/2J mice but not in the A/J mice. This corresponds with immunoreactivity of LC3, an autophagy marker, in A/J tissues at 10 days and 2 wk. The differences in gene expression were examined at 1 wk, 10 days, and 2 wk old, because divergent growth occurred during this period. The DBA/2J's carotid body at 1 wk old showed a greater expression of Msx2 than the A/J's carotid body. No other candidate genes showed consistent differences between the ages and strains. The difference was not seen in sympathetic cervical ganglia of 1 wk old, suggesting that the difference is carotid body specific. The current study indicates the critical postnatal period for developing distinctive morphology of the carotid body in these mice. Further studies are required to further elucidate a role of Msx2 and other uninvestigated genes.

Predominant role of peripheral chemoreceptors in the termination of apnea in maturing newborn lambs

1996 ◽  
Vol 80 (3) ◽  
pp. 892-898 ◽  
Author(s):  
C. Delacourt ◽  
E. Canet ◽  
M. A. Bureau
Keyword(s):  
Carotid Body ◽  
Pco2 Level ◽  
Peripheral Chemoreceptor ◽  
Arterial Pco2 ◽  
Postnatal Maturation ◽  
Body Function ◽  
Life Threatening ◽  
Prolonged Apnea ◽  
Arterial Po2

Apneas are very common and normal in newborns but may become life threatening if they are not terminated appropriately. The aim of this study in newborn lambs was to investigate the influence on apnea termination of postnatal maturation, peripheral chemoreceptor function, and hypoxia. Apneas were induced by passive hyperventilation at varying inspired O2 fraction levels. The apnea termination threshold PCO2 (PATTCO2) was defined as the arterial PCO2 value at the first breath after the apnea. Three groups of awake intubated lambs were studied: 1) intact lambs tested at both 1 and 15 days of life, 2) intact 1-day-old lambs with central tissue hypoxia induced by CO inhalation, and 3) 1-day-old lambs with carotid body denervation (CBD). In individual lambs and regardless of age and carotid body function, there was a PO2-PCO2 response curve that was a determinant for the termination of an apnea. PATTCO2 invariably increased when arterial PO2 increased, regardless of age. During hypoxia and normoxia, PATTCO2 was significantly lower in 15-day-old lambs compared with 1-day-old lambs. No difference was seen during hyperoxia. PATTCO2 values were shifted to higher levels after carotid body removal. Finally, hypoxia induced by either a low inspired O2 fraction or CO inhalation consistently failed to induce a depressive effect on the PATTCO2 even in CBD lambs. In conclusion, in awake newborn lambs, the PCO2 level for apnea termination changed with postnatal age, and carotid body function was essential in lowering PATTCO2, thus protecting the lambs against prolonged apnea. Furthermore, hypoxia consistently failed to depress the reinitiation of breathing after apnea, even in CBD lambs.

Early postnatal development of electrophysiological and histological properties of sensory sural nerves in male rats that were maternally deprived and artificially reared: Role of tactile stimulation

2017 ◽  
Vol 78 (4) ◽  
pp. 351-362 ◽  
Author(s):  
Rene Zempoalteca ◽  
Mercedes G. Porras ◽  
Suelem Moreno-Pérez ◽  
Gabriela Ramirez-Funez ◽  
Elsa L. Aguirre-Benítez ◽  
...  
Keyword(s):  
Postnatal Development ◽  
Tactile Stimulation ◽  
Male Rats ◽  
Early Postnatal Development ◽  
Sural Nerves

Postnatal development of the renal medulla; role of the renin-angiotensin system

2013 ◽  
Vol 208 (1) ◽  
pp. 41-49 ◽  
Author(s):  
K. Madsen ◽  
A. R. Tinning ◽  
N. Marcussen ◽  
B. L. Jensen
Keyword(s):  
Postnatal Development ◽  
Renin Angiotensin System ◽  
Renal Medulla ◽  
Angiotensin System ◽  
Renin Angiotensin
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