Neurotransmitters are often synthesized from amino acids. They have different functions in the body, often either inhibiting or exciting the neuron that it targ

Neurotransmitters are often synthesized from amino acids. They have different functions in the body, often either inhibiting or exciting the neuron that it targets. There are a bunch of different aspects to being awake. Caffeine works on adenosine, which has to do with wakefulness. But also things like adrenaline have a different aspect of wakefulness that amphetamines target. Modafinil targets orexin receptors I believe, which involve wakefulness as well as eating.