Search
Presentation Details
| Poster #330 Regulation of breathing and sniffing by the locus coeruleus in mice |
| Yingqi Wang1, Brittany Chapman2, Sravana Nuti1, Steven A. Thomas1, Minghong Ma1, Janardhan P. Bhattarai1 1University of Pennsylvania, Philadelphia, PA, United States 2Cypris, Philadelphia, PA, United States |
As a vital sign, breathing is constantly modulated by external stimuli and internal states. Sniffing, a distinct breathing pattern, is essential for animals to navigate the environment, and in rodents, it entails an integrated action including high-frequency breathing. Sniffing can be triggered by odors and other salient stimuli or occur spontaneously, reflecting an internal drive for exploration. However, the neural mechanisms that regulate sniffing under different behavioral contexts remain largely unknown. Here we hypothesize that the locus coeruleus (LC) is involved in the regulation of sniffing given its role in mediating arousal and its reciprocal connections with the preBötzinger Complex (preBötC), a breathing center in the brainstem. We used the dopamine b-hydroxylase (DBH)-Cre mice to gain genetic access to LC noradrenergic neurons. Via Ca2+-based fiber photometry in freely behaving mice, we found that the activity of LC neurons is temporally coupled to sniffing, either spontaneously occurred or triggered by external stimuli in different sensory modalities (e.g., odor presentation, light-dark transition, and marble drop). Moreover, chemogenetic inhibition decreased the breathing frequency in response to salient sensory stimuli in a task-dependent manner. Finally, optogenetic activation of LC neurons increased the breathing frequency under anesthesia but not in wakefulness. These results suggest that LC noradrenergic neurons regulate breathing/sniffing in a state- and context-dependent manner. |