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Turk, A. Z.

Publications and source records attributed to Turk, A. Z..

2 recordsLinked to original sources

Whole-brain analysis of CO2 chemosensitive regions and identification of the retrotrapezoid and medullary raphe nuclei in the common marmoset (Callithrix jacchus)

Respiratory chemosensitivity is an important mechanism by which the brain senses changes in blood partial pressure of CO2 (PCO2). It is proposed that special neurons (and astrocytes) in various brainstem regions play key roles as CO2 central respiratory chemosensors in rodents. Although common marmosets (Callithrix jacchus), New-World non-human primates, show similar respiratory responses to elevated inspired CO2 as rodents, the chemosensitive regions in marmoset brain have not been defined yet. Here, we used c-fos immunostainings to identify brain-wide CO2-activated brain regions in common marmosets. In addition, we mapped the location of the retrotrapezoid nucleus (RTN) and raphe nuclei in the marmoset brainstem based on colocalization of CO2-induced c-fos immunoreactivity with Phox2b, and TPH immunostaining, respectively. Our data also indicated that, similar to rodents, marmoset RTN astrocytes express Phox2b and have complex processes that create a meshwork structure at the ventral surface of medulla. Our data highlight some cellular and structural regional similarities in brainstem of the common marmosets and rodents.

physiology↗

Breathing Behaviors in Common Marmoset (Callithrix jacchus)

The respiratory system maintains homeostatic levels of oxygen (O2) and carbon dioxide (CO2) in the body through rapid and efficient regulation of frequency and depth (tidal volume) of breathing. Many studies on homeostatic control of breathing have been done on rodent animal models, in which they have relatively reduced chemosensitivities when compared with primates. The use of common marmoset (Callithrix jacchus), a New World non-human primate model, in neuroscience is increasing, however, the data on their breathing is limited and their respiratory behaviors have yet to be characterized. Using Whole-body Plethysmography in room air as well as in hypoxic (low O2) and hypercapnic (high CO2) conditions, we defined breathing behaviors in awake, freely behaving marmosets. Additionally, we optimized an analysis toolkit for unsupervised analysis of respiratory activities in common marmoset. Our data indicate that marmosets exposure to hypoxia decreased metabolic rate and increased sigh rate. However, the hypoxic condition did not augment the ventilatory response. Hypercapnia, on the other hand, increased both the frequency and tidal volume. In this study, we described breathing behaviors of common marmosets in a variety of O2 and CO2 conditions.

neuroscience↗