When absorbed by receptor sites, what type of message does a neurotransmitter deliver?

excitatory and inhibitory responses

Explanation:

Neurotransmitters are known as "chemical messengers." These messengers are released by the neurons (nerve cells) and cause an effect when absorbed by certain receptors. The effect will largely depend on the type of the receptor. The message delivered could be "excitatory" or "inhibitory."

For example, let's take the role of "Acetylcholine." This is a neurotransmitter that aids in the function of humans' and animals' brain. The skeletal muscles of the body has nicotonic acetylcholine receptor. When the acetylcholine receptor binds with it, it causes an excitatory response. This response is responsible for muscle contraction. On the contrary, the acetylcholine receptor causes an inhibitory response in the cardiac muscle. This slows down the contraction of the heart.