Pharmacology Notes

Norepinephrine and Serotonin
Both norepinephrine and serotonin seem to be involved in similar functions within the brain: regulation of appetite, sleep, arousal, mood, temperature, and hormone release.

Norepinephrine is also known as noradrenaline. As a stress hormone, it aff ects parts of the human brain where attention and responding actions are controlled. It is released from the medulla of the adrenal glands as a hormone into the blood, but is also a central and sympathetic nervous system neurotransmitter.

Serotonin is a neurotransmitter synthesized in the CNS as well as the gastrointestinal tract. It is believed to play an important role in regulating anger, aggression, body temperature, mood, sleep, vomiting, sexuality, and appetite. It was initially identified as a vasoconstrictor present in blood serum, and it was from here that its name was derived. Serotonin (also known as 5-hydroxytryptamine or 5-HT) may also have a role in pain
perception and behavior. It acts as an inhibitory neurotransmitter. A rare condition known as serotonin syndrome, also known as serotonin toxicity, can result from intentional self-poisoning with serotonin, use of the drug therapeutically, or from inadvertent drug interactions. This condition includes progressively worsening symptoms such as: mental confusion, shivering or muscle twitching, sweating or fever, hallucinations, hypertension, tachycardia, headache, tremor, nausea, diarrhea, coma, and death.