Neurotransmitters are the brain’s chemical messengers, carrying signals between neurons. Some excite activity (e.g., glutamate), while others inhibit it (e.g., GABA). Well-known neurotransmitters like dopamine, serotonin, and noradrenaline shape mood, motivation, and behaviour. Once released, neurotransmitters are quickly cleared through breakdown (enzymes destroy them) or reuptake (they are reabsorbed back into the releasing neuron). This keeps brain signalling precise. Many medications, such as…