Neurotransmitters go Knock Knock

Knock knock. Who's there? 

Glutamate. Glutamate who? Glutamate to meet you!

GABA. GABA who? GABA nice day today, isn't it?

Dopamine. Dopamine who? Do-pa-mine if I tell you a joke?

Serotonin. Serotonin who? Serotoninly you didn't forget about me!

Adrenaline. Adrenaline who? Adrenaline junkie looking for a good time!

Norepinephrine. Norepinephrine who? Norepinephrine me, I'm just a little jumpy!

Histamine. Histamine who? Histamine, can you pass the tissues? Ah-Choo!!

Adenosine. Adenosine who? Adenosine very much, but could you please be quiet?

Nitric oxide. Nitric oxide who? Nitric oxide more jokes, I promise!

Substance P. Substance P who? Substance P careful, don't touch that, it might be hot!

Endorphins. Endorphins who? Endorphins, I'm feeling good!

Anandamide who? Anandamide, your body's natural bliss molecule!

Neuropeptide Y. Neuropeptide Y who? Neuropeptide Y not tell me a joke?

Orexin. Orexin who? Orexin, I must have fallen asleep, did you say something?

Acetylcholine. Acetylcholine who? Acetylcholine-drenalin is pumping through my veins, this joke is making me excited!

Endocannabinoids. Endocannabinoids who? Endocannabinoids what you can do for me lately? I'm feeling kind of stressed out!