Q: What exactly are urban legends? A: Urban legends are popular stories alleged to be true and passed from individual to individual via oral or written (e.g. forwarded email) communication.: What exactly are urban legends? A: Urban legends are popular stories alleged to be true and passed from individual to individual via oral or written (e.g. forwarded email) communication.
When a person gets injured, their brains release chemicals called opioids into the space between neurons that acts to dull the pain signals. The effect is seen the most in the brain regions called the ventral striatum, amygdala, midline thalamus, and periaqueductal gray.
Nicotine and Neurotransmitter Release. Stimulation of nicotinic cholinergic receptors releases a variety of neurotransmitters in the brain. One of them, dopamine, signals a pleasurable experience and is critical for the reinforcing effects (effects that promote self-administration)of nicotine and other drugs of abuse.