Acetylcholine

Acetylcholine is a neurotransmitter used at the neuromuscular junction—that means, it is the chemical that motor neurons of the nervous system release in order to activate muscles. In the brain, acetylcholine functions as a neurotransmitter and as a neuromodulator. The brain contains a number of cholinergic areas, each with distinct functions. They play an important […]

Adrenaline / Epinephrine

Epinephrine, also known as adrenaline, is a hormone and neurotransmitter. It’s also sold as a drug. It increases heart rate, constricts blood vessels, dilates air passages and participates in the fight-or-flight response of the sympathetic nervous system. Chemically, epinephrine is a catecholamine, a monoamine produced only by the adrenal glands from the amino acids phenylalanine and […]