Is the locus coeruleus microglia involved in the respiratory response to hypercapnia and in CO2-induced panic attacks?

Abstract

Panic attack is a condition marked by intense anguish and anxiety, in which the patient quickly develops respiratory symptoms such as shortness of breath, hyperventilation and a feeling of suffocation. Although the mechanisms of this pathology remain unknown, recent studies suggest a probable connection between respiratory challenges and panic disorders, since episodes of hypoxia or hypercapnia can trigger pathologies related to anxiety. Locus coeruleus (LC) is a chemosensitive region capable of generating emotional and physical responses during stress. In addition, LC has noradrenergic neurons that play an important role in the ventilatory response to CO2, and hypercapnia can trigger panic attacks. Recent studies also suggest a possible connection between microglia cells and panic attacks, since the microglia's proinflammatory responses contribute to the detection of a homeostatic imbalance, such as CO2 inhalation. Despite this, the involvement of the LC microglia in the ventilatory response and the behavioral changes induced by high concentrations of CO2 is not yet fully known, which is a model used to induce panic attacks. Thus, the present work proposes to investigate whether the microglia of the LC of mice is activated in response to hypercapnia in a panic attack model (exposure to 20% CO2), seeking to provide more specific information about the pathophysiology of panic disorder and possible aid in the development of future treatments. (AU)