What role do orexins play in individuals with panic disorder?

Orexins, also known as hypocretins, are neuropeptides that are primarily involved in the regulation of wakefulness, vigilance, and appetite. In individuals with panic disorder, research suggests that orexins can influence the arousal and anxiety associated with panic attacks. The heightened state of arousal linked to panic episodes may be related to increased levels of orexin activity, which enhances alertness and readiness to respond to perceived threats. This connection between orexins and the mechanisms of panic disorder underscores the role of these neuropeptides in the physiological responses to stress and anxiety, making them crucial to understanding the disorder's underlying processes.

The other options, while they describe other functions associated with different systems or processes, do not directly relate to the role of orexins in panic disorder as effectively as the focus on wakefulness, vigilance, and appetite. Memory retention and learning, emotional expression, and regulating sleep cycles involve different neurobiological pathways and hormones that do not specifically capture the significant influence of orexins in panic disorder contexts.