INTRODUCTION: Post-Traumatic stress disorder (PTSD) is a psychiatric issue caused by traumatic events like war, violence, or natural disasters. Its symptoms and brain mechanisms are well-understood, but the molecular pathways involved in its development and recovery remain unknown. We hypothesise that hypoxia and hypoxia-induced factors may play a role in reducing PTSD symptoms by influencing BDNF, as studies show intermittent hypoxia increases BDNF expression.

AIM(S): Our goal was to investigate how different types of hypoxia can affect PTSD-like behaviour in rats. In this way, we wanted to understand whether there is a need to study in more detail the molecular mechanisms of hypoxia's effect on the formation of PTSD and the restoration of physiological behaviour.

METHOD(S): The first group received oral cobalt chloride (15 mg/kg) once daily for the week. The second was in a hypoxic chamber with 14% of oxygen each day for a week. Hypobaric hypoxia was reproduced by ‘lifting’ animals in a barometric chamber to an ‘altitude’ up to 4500 meters. Each group had 24 rats, split into control and PTSD-like groups. To model PTSD behaviour in rats, we have used single-prolonged stress methods. Behavioural tests included the Open Field, Dark-Light Box Test, and Elevated Plus Maze.

RESULTS: PTSD animals showed elevated anxiety, which was reduced by intermittent hypoxia and hypobaric chamber exposure: light zone occupancy recovered by 57% and 90% respectively (p<0.05), corner time normalized to 3.9-fold (p<0.05), and erratic locomotion decreased with path efficiency improving by 93% (p<0.05), indicating that hypoxic interventions effectively attenuate core PTSD-like behavioural symptoms.

CONCLUSIONS: Throughout the three methods, intermittent hypoxia consistently influenced PTSD-like rats by boosting exploration and reducing avoidance. In control rats, it had opposite effects, suggesting a modulatory role in behaviour. This highlights the need for further research into the molecular pathways of hypoxia's impact on PTSD mechanisms.

FINANCIAL SUPPORT: One of co-authors was supported by IC AMER of NAS of Ukraine