"The brain contains billions and billions of neurons. These cells communicate with one another by releasing small endogenous chemical messengers, called neurotransmitters, into the synapse, where they are then taken up by specific receptors on neighboring cells. There are many types of neurotransmitters in the brain—what they have in common is that they are produced inside a neuron, released into the synapse, and then cause an excitatory or inhibitory effect on receptor cells, helping to propagate or downgrade action potentials."
This is something that psychology students need to know, firstname.lastname@example.org
Via Maggie Rouman, Maria_Ana, Deborah McNelis, M.Ed, Tom Perran