TY - JOUR TI - C1 neurons are part of the circuitry that recruits active expiration in response to the activation of peripheral chemoreceptors AU - Malheiros-Lima, Milene R AU - Silva, Josiane N AU - Souza, Felipe C AU - Takakura, Ana C AU - Moreira, Thiago S A2 - Calabrese, Ronald L A2 - Ramirez, Jan-Marino A2 - Huckstepp, Robert VL - 9 PY - 2020 DA - 2020/01/23 SP - e52572 C1 - eLife 2020;9:e52572 DO - 10.7554/eLife.52572 UR - https://doi.org/10.7554/eLife.52572 AB - Breathing results from the interaction of two distinct oscillators: the pre-Bötzinger Complex (preBötC), which drives inspiration; and the lateral parafacial region (pFRG), which drives active expiration. The pFRG is silent at rest and becomes rhythmically active during the stimulation of peripheral chemoreceptors, which also activates adrenergic C1 cells. We postulated that the C1 cells and the pFRG may constitute functionally distinct but interacting populations for controlling expiratory activity during hypoxia. We found in rats that: a) C1 neurons are activated by hypoxia and project to the pFRG region; b) active expiration elicited by hypoxia was blunted after blockade of ionotropic glutamatergic receptors at the level of the pFRG; and c) selective depletion of C1 neurons eliminated the active expiration elicited by hypoxia. These results suggest that C1 cells may regulate the respiratory cycle, including active expiration, under hypoxic conditions. KW - hypoxia KW - ventrolateral medulla KW - breathing KW - expiration KW - optogenetics JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -