Approaching hurricane effects on phrenic motor plasticity: the Florida experience.

Phrenic long-term facilitation (pLTF) is a form of respiratory motor plasticity elicited by moderate acute intermittent hypoxia (mAIH). Although certain factors such as aging and inflammation undermine mAIH-induced pLTF, little is known concerning the effects of physiological stress. Over several decades, accumulated anecdotal evidence from our laboratory suggests that major construction near the animal facility, or other events thought to elicit stress responses in rats, undermine mAIH-induced pLTF and cause unstable phrenic bursting accompanied by spontaneous phrenic nerve "apneas" post-AIH; the reasons for stress-induced instability are unknown. Here, we document chance observations of similar effects on phrenic nerve activity during the 2024 Florida hurricane season. Approaching hurricanes ±5 days from landfall in Florida were associated with unstable phrenic nerve activity, neural apneas, and increased serum stress hormone levels in anesthetized adult (3-4 mo) male Sprague-Dawley rats. We summarize observations concerning the impact of hurricanes and discuss the role of stress hormones, underscoring the need to consider factors known to elevate stress hormones in studies of respiratory control, including respiratory motor plasticity.NEW & NOTEWORTHY Over several decades, anecdotal evidence from our laboratory suggests that stress undermines respiratory (phrenic) motor plasticity elicited by acute intermittent hypoxia and destabilizes phrenic nerve activity for unknown reasons. During the 2024 Florida Hurricane Season, we observed that approaching hurricanes were associated with unstable phrenic nerve activity, neural apneas, and increased serum stress hormone levels, highlighting the need to consider factors known to elevate stress hormones in studies of breathing stability and/or neuroplasticity.