Rosatti Marcelo Rafanelli, Gargaglioni Luciane H, Dias Mirela B
Department of Structural and Functional Biology, Physiology, Institute of Bioscience, Sao Paulo State University-UNESP, Botucatu, SP, Brazil.
Department of Animal Morphology and Physiology, Sao Paulo State University-FCAV, Jaboticabal, SP, Brazil.
Respir Physiol Neurobiol. 2025 Jan;331:104352. doi: 10.1016/j.resp.2024.104352. Epub 2024 Sep 17.
Brainstem astrocytes are important for COH chemoreception. Lateral Hypothalamus/Perifornicial Area (LH/PFA) neurons have an excitatory effect on the ventilatory response to CO, however the role of the astrocytes is unknown. We hypothesized that LH/PFA astrocytes play an excitatory role in the hypercapnic ventilatory response in a sleep-wake and light-dark cycles-dependent manner. We manipulated the activity of astrocytes in the LH/PFA of male Wistar rats through microinjection of Fluorocitrate (Fct), which selectively affects astrocytes, inducing the exocytosis of gliotransmitters. We investigated the effects of intra-LH/PFA Fct microinjection on resting breathing and ventilatory responses to hypercapnia and hypoxia during wakefulness and NREM sleep, in the light and dark phases. Fct increased ventilation during hypercapnia but not during room air or hypoxia. The hypercapnic chemoreflex was increased exclusively during the dark-active phase during both, wakefulness and NREM sleep, indicating that LH/PFA astrocytes play an excitatory role in hypercapnic ventilatory response in a light-dark cycle-dependent manner.
脑干星形胶质细胞对化学感受性呼吸控制（COH）很重要。下丘脑外侧区/穹窿周区（LH/PFA）神经元对CO引起的通气反应有兴奋作用，然而星形胶质细胞的作用尚不清楚。我们假设LH/PFA星形胶质细胞在高碳酸通气反应中以睡眠-觉醒和明暗周期依赖的方式发挥兴奋作用。我们通过显微注射氟柠檬酸（Fct）来操纵雄性Wistar大鼠LH/PFA中星形胶质细胞的活性，氟柠檬酸选择性地影响星形胶质细胞，诱导神经胶质递质的胞吐作用。我们研究了在明暗周期的清醒和非快速眼动睡眠期间，向LH/PFA内显微注射Fct对静息呼吸以及对高碳酸血症和低氧血症的通气反应的影响。Fct在高碳酸血症期间增加了通气，但在常氧或低氧期间没有增加。高碳酸化学反射仅在清醒和非快速眼动睡眠期间的暗活动期增加，表明LH/PFA星形胶质细胞在高碳酸通气反应中以明暗周期依赖的方式发挥兴奋作用。
