Genetically-targeted Recordings from Respiratory Chemoreceptor Neurons in the Retrotrapezoid Nucleus of Freely Behaving Mice by Fiber Photometry

• DOI: 10.1152/physiol.2024.39.s1.828
• Publication Date: 2024-05-21T14:57:50Z
• Authors: George Souza; Daniel Stornetta; Stephen Abbott
• Keywords: Central chemoreceptors

Central respiratory chemoreceptors regulate breathing homeostasis in relation to arterial pH/PCO 2 . Neurons located the retrotrapezoid nucleus (RTN) are considered function as central and/or be part of neural network that drives chemoreflex. RTN neurons sensitive changes pH vitro under synaptic blockade and anesthetized preparations with artificial ventilation. However, there is limited information about their activity vivo non-anesthetized conditions. Recent studies have shown Nmb-expressing acid-sensitive properties necessary for response CO In this study, we hypothesized RTN- Nmb activated during hypercapnia freely behaving condition. To test hypothesis, measured dynamic using a genetically encoded calcium indicator (GCaMP7s) via fiber photometry mice. Expression GCaMP7s was targeted by microinjection Cre-dependent viral vector (AAV 1 -Syn-Flex-jGCAMP7s) transgenic Nmb-Cre One month later, animals were placed plethysmography chamber simultaneously record fluorescence from During hypercapnia, markedly activated, effect size graded F I (DF/F 0 baseline: 1.9 ± 1.0 % at 0.03, 8.0 4.0% 0.06 12.0 5.0% 0.09, n=6), significantly different each level (RM One-way ANOVA, p=0.0012). Importantly, increase neuron correlates (p<0.0001, R =0.97) frequency =0.85). This study shows potently conditions, aligns breathing. These results consistent concept monitor PCO /pH essential hypercapnic ventilatory response. supported National Institutes Health (HL148004 ) Stephen BG Abbott. full abstract presented American Physiology Summit 2024 meeting only available HTML format. There no additional versions or content abstract. not involved peer review process.