AP PSYCHOLOGY

Detailed explanation-1: -An antagonist is a molecule that blocks the effect that the neurotransmitter normally has on the post-synaptic neuron. It was long thought that a given neuron released only one kind of neurotransmitter. But today, many experiments show that a single neuron can produce several different neurotransmitters.

Detailed explanation-2: -Therefore, an agonist amplifies a neurotransmitter’s normal effects and an antagonist reduces them. Chlorpromazine and haloperidol are antagonists for dopamine as they block the receptors to limit the uptake of dopamine.

Detailed explanation-3: -Activation of presynaptic receptors for a variety of neurotransmitters and neuromodulators inhibits transmitter release at many synapses. Such presynaptic inhibition might serve as a means of adjusting synaptic strength or preventing excessive transmitter release, or both.