Neurotransmitter reuptake allows a neuron to absorb a signaling chemical after it has sent a message, so it can be reused. In addition to allowing the brain to recycle valuable chemicals, it acts to put a brake on signals, limiting the amount of time neurotransmitters spend in the synapse. This can be important for regulation of certain reactions where the nervous system doesn’t want an extended reaction to a stimulus. Certain medications act by inhibiting this process to increase the circulation of signal chemicals in the synapse.
The process of sending chemical signals between neurons starts with the release of a neurotransmitter which enters the space between cells, known as the synapse. If the cell on the other hand has the right receptors, the chemical can lock on to stimulate or inhibit the neuron. In neurotransmitter reuptake, carrier molecules attach to the used chemicals and push them back into the terminal, the area of the neuron that releases them. This process happens in a very short period of time, allowing neurons to send messages, recover, and transmit again at a rapid rate.
Recycling neurotransmitters can help the brain recover more quickly between signals, because it will have new resources available to send another signal. These chemicals take time and energy to make and increasing efficiency helps the brain function. The neurotransmitter reuptake process also limits the amount of time spent in the synapse, so people don’t experience extended stimulation of selected neurons. Carrier proteins can be used to control the duration of a neurotransmitter’s signal.
Dopamine, norepinephrine, and serotonin are common examples of chemicals processed with neurotransmitter reuptake. Some are more subject to reuptake than others, depending on their function. Between individuals, there can be considerable variations in the concentration of chemicals in the brain and the number of neurotransmitters produced over time. The process can also be affected by diet, medications, and other environmental factors. This can result in very different levels of cognitive function and activity.
People with certain neurochemical imbalances may experience neurotransmitter reuptake too quickly, or a reduced production of certain chemicals in the brain. They can benefit from medications that inhibit the reuptake process; Selective Serotonin Reuptake Inhibitors (SSRIs) are an example. Medications may help address depression, anxiety, and other mental health problems. They must be used and stopped with care, as the brain needs time to adjust to them and to recover when patients stop taking them.