Norepinephrine, also called noradrenaline, is both a neurotransmitter and a hormone that plays crucial roles in the brain and body. It is involved in the regulation of arousal, attention, cognitive function, and stress reactions

. Functions in the brain:

• Increases arousal and alertness
• Promotes vigilance and focus
• Enhances memory formation and retrieval
• Regulates sleep-wake cycles, helping you wake up and stay attentive
• Influences mood and can affect anxiety levels

Functions in the body:

• Acts as part of the fight-or-flight response to stress or danger by mobilizing the body for action
• Increases heart rate and blood pressure by causing blood vessels to constrict
• Redirects blood flow to skeletal muscles and away from the gastrointestinal system
• Triggers release of glucose from energy stores to provide quick energy
• Dilates pupils to improve vision in stressful situations
• Regulates bodily functions such as tear production, kidney function (renin release), and immune system activity

Norepinephrine is released by neurons in the sympathetic nervous system and by the adrenal glands during stress, enabling rapid physical and mental responses to threats

. In summary, norepinephrine prepares the brain and body to respond to stress by increasing alertness, energy availability, cardiovascular output, and focus, while also influencing mood and cognitive functions. It plays a vital role in maintaining homeostasis and enabling adaptive responses to environmental demands.