How Arousal States Impact Retrotrapezoid Nucleus Neuron Activity during Breathing
George Souza, Daniel S. Stornetta, and Stephen B. G. Abbott
(see article e1587242024)
Researchers continue to explore how our central nervous systems control breathing across arousal states. Studies using anesthetized animals show that retrotrapezoid nucleus (RTN) neurons expressing Phox2b and neuromedin B are necessary for the homeostatic breathing response that occurs when there is too much carbon dioxide in the blood. Souza et al. investigated whether this is the case in unanesthetized mice. The authors used fiber photometry to record from mouse RTN neurons across sleep–wake states in vivo. They confirmed that RTN neurons are sensitive to carbon dioxide in behaving mice. The authors discovered that RTN neurons exhibit high sensitivity to arousal states and that this sensitivity impacts how the RTN responds to high blood carbon dioxide levels. During waking and REM sleep, which are considered heightened states of arousal, RTN neurons were most active. According to the authors, this study is a breakthrough in our understanding of how carbon dioxide–sensitive neurons in the RTN exhibit arousal state-dependent activity, which advances our understanding of the mechanisms that drive breathing problems.
The arrows point to GCaMP-expressing RTN neurons coexpressing Nmb. See Souza et al. for information on how they used fiber photometry to record the fluorescent activity of RTN neurons.
Problem Gamblers Have Impaired Behavioral Adjustment Following Losses
Kiyohito Iigaya, Tobias Larsen, Tim Fong, and John P. O’Doherty
(see article e0080242024)
Millions of people in America suffer from problematic gambling issues. Iigaya et al. investigated why people who engage in problematic gambling continue this behavior despite repeated losses that worsen their quality of life. The researchers used a decision-making task to probe behavior related to reward learning and aversion to loss as they imaged the brains of 21 male and 19 female study participants. This methodology revealed that problem gamblers are less able to adjust their predictions following losses as compared with recreational gamblers. According to the researchers, this may be because people who gamble problematically rely more on long-term learning, integrating information slowly over a longer time scale, and are less able to learn rapidly from the losses in their immediate pasts. Neuroimaging revealed that the medial prefrontal cortex and insula contributed to this learning disparity, pointing to potential treatment targets in problem gamblers.
Footnotes
This Week in The Journal was written by Paige McKeon