Breathing Behaviors in Common Marmoset (Callithrix jacchus)

Abstract

The respiratory system maintains homeostatic levels of oxygen (O2) and carbon dioxide (CO2) in the body through rapid and efficient regulation of frequency and dept (tidal volume) of breathing. The use of common marmoset (Callithrix jacchus), a New World non-human primate (NHP) 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 sought to define breathing behaviors in an awake, freely behaving marmosets. Additionally, we instituted and optimized an analysis toolkit for unsupervised analysis of the respiratory activities in common marmoset. Our findings indicate that marmoset’s exposure to hypoxia decreased metabolic rate and increased sigh rate. However, the hypoxic condition did not augment the ventilatory response as reported in other animals. Hypercapnia, on the other hand, increased both the frequency and tidal volume as expected. In this study, we shed light on the breathing behaviors of common marmosets in a variety of O2 and CO2 conditions to further understand the breathing behaviors in NHPs.

Whole-brain analysis of CO2chemosensitive regions and identification of the retrotrapezoid and medullary raphé nuclei in the common marmoset (Callithrix jacchus)

“…Data from rodents and cats suggest that RTN and medullary raphé (i.e., raphe magnus and pallidus) act as central CO 2 chemosensitive center in the brainstem (Stornetta et al 2006; Teppema et al 1994; Takakura et al 2014). While it has been shown that the common marmoset, a New-World non-human primate, has a similar hypercapnic respiratory response to that of rodents and humans (Bishop et al 2021), the brainstem central chemosensitive regions of the RTN and medullary raphé have yet to be mapped. Accordingly, in this study we performed a whole-brain analysis of CO 2 chemosensitive regions in marmoset’s brain and additionally identified putative locations of RTN and medullary raphé in the marmoset brainstem.…”

“…As a non-human primate, the common marmoset has been proposed as a powerful animal model for social and physiological studies in neuroscience (Prins et al 2017; Walker et al 2017; Mitchell and Leopold 2015; Miller et al 2016; Bishop et al 2021; Mansfield 2003; Burkart and Finkenwirth 2015; SheikhBahaei 2020). Compared to rodents’ brain, the marmosets brain is more alike to that of humans (Passingham et al 2013), however, the size of the marmoset - closer to that of a rodent – makes it an appealing laboratory animal model for physiological experiments.…”

“…Whole-body plethysmography was used to record respiratory activity in unrestrained awake marmosets, as described previously (Bishop et al 2021). Briefly, on the day of the experiment, the marmoset was placed in a Plexiglas recording chamber (∼3 L) that was flushed continuously with a humidified room air (temperature 26-28 °C) at a rate of 2.2 L min −1 .…”

“…Recently we have shown that hypercapnia augments frequency and depth of breathing in the common marmoset ( Callithrix jacchus ) (Bishop et al 2021), a New World non-human primate animal model. This hypercapnia-induced respiratory response is comparable to respiratory responses reported in other mammals (Boddy et al 1974; Hoffman et al 1982; Kuwaki et al 1996; Douglas et al 1982; Kong and Berger 1986).…”