Drugs interfere with the way neurons send, receive, and process signals via neurotransmitters. Some drugs, such as marijuana and heroin, can activate neurons because their chemical structure mimics that of a natural neurotransmitter in the body. This allows the drugs to attach onto and activate the neurons.
Drugs interfere with the way neurons send, receive, and process signals via neurotransmitters. Every substance has slightly different effects on the brain, but all addictive drugs, including alcohol, opioids, and cocaine, produce a pleasurable surge of the neurotransmitter dopamine in a region of the brain called the basal ganglia; neurotransmitters are chemicals that transmit messages between nerve cells.
naturally, through diet or exercise or drugs, specifically receptor antagonists
diet/exercise - diet is self explanatory, since a healthy diet would mean that your body would be balanced, and wouldn't struggle with producing NTs
drugs - any type of drug will mimic the behavior of NTs, but receptor antagonists specifically will increase the concentration of neurotransmitters in a synapse. Antagonists would block the receptors, and thus the NTs that were intended for the blocked space, will not have anywhere to go. As a result, the NTs will stay in the synapse, and cause an increase in the concentration of NTs.
ps: you'd have more luck asking this question in biology