There are two types of removal: Re-uptake – the neurotransmitter is reabsorbed back into the presynaptic neuron and restored inside a vesicle ready to be used again. For example, noradrenaline.

However, a series of weak stimuli can combine, increasing the amount of neurotransmitter that is released. This results in enough neurotransmitter being diffused across the synaptic cleft to ...

clinical depression can arise or worsen as the result of lowering the CNS availability of building blocks for serotonin (and possibly other neurotransmitters). Yet it remains an open question to ...