What is serotonin?

This is a neurotransmitter and is a compound found in tissues in the body. Much of the 5-HT in the brain is found in a small collection of neurones at the base of the brain called the “raphe nuclei” From there, the neurones have axons that reach all the way into the cortex. 5-HT is released at synapses of these axons with cortical neurones. When this happens, the activity of the neural circuits and networks is altered. 5-HT is known to modulate sleep, appetite, sexual activity and mood (as well as other things). Drugs that prolong or increase its effect are used as antidepressants eg. SSRI, SNRI.