A molecule of neurotransmitter is to a(n) _____ as a key is to a keyhole.

Endorphins help the body to

Lately, Kiara has been having trouble sleeping at night, and has also experienced a sharp decline in appetite and energy level. A decrease in which of the following neurotransmitters might be responsible for Kiara's sudden change in behavior?

An _____ is a chemical substance that mimics or enhances the effects of a neurotransmitter.

_____ is the release of a neural impulse, consisting of a reversal of the electrical charge within the axon.

The first identified neurotransmitter was

When neurons fire and transmit messages, they

A molecule of neurotransmitter is to a(n) _____ as a key is to a keyhole.