The Locus Coeruleus- Norepinephrine System in Stress and Arousal: Unraveling Historical, Current, and Future Perspectives

Arousal may be understood on a spectrum, with excessive sleepiness, cognitive dysfunction, and inattention on one side, a wakeful state in the middle, and hypervigilance, panic, and psychosis on the other side. However, historically, the concepts of arousal and stress have been challenging to define as measurable experimental variables. Divergent efforts to study these subjects have given rise to several disciplines, including neurobiology, neuroendocrinology, and cognitive neuroscience. We discuss technological advancements that chronologically led to our current understanding of the arousal system, focusing on the multifaceted nucleus locus coeruleus. We share our contemporary perspective and the hypotheses of others in the context of our current technological capabilities and future developments that will be required to move forward in this area of research.

Automated summary

Arousal can be understood as a spectrum with different states on each side, and historically, defining arousal and stress as measurable experimental variables has been challenging. Efforts to study these subjects have led to the development of disciplines such as neurobiology, neuroendocrinology, and cognitive neuroscience. Advancements in technology have contributed to our current understanding of the arousal system, particularly in relation to the locus coeruleus nucleus.