Neurotransmitters are chemical messengers that help relay information throughout the body. They transmit information through specialized nerve cells called neurons. How this works is that a signal is sent from the beginning of neuron (called the dendrite) to the other end (called the axon). At that point, information can be sent to other neurons via the release of neurotransmitters.

neurotransmitter reuptake diagramNeurotransmitters are released from the axon and must travel across a small space (called a synapse) where they can dock with receptors on one or more other neurons to keep the information flowing. Once the information has been sent, neurotransmitters travel back across the synapse where they can be taken back into the axon (via a gate called a reuptake transporter) where they are safe from destruction and can be used again when necessary.

The Importance of Neurotransmitter Reuptake

The process of moving the neurotransmitters from the synapse back into the axon of the neuron is called “neurotransmitter reuptake”, and it plays a crucial role in long-term health. When neurotransmitters are in the synapse (the space between neurons) they are exposed to a number of enzymes (including monoamine oxidase (MAO) and catechol-O-methyl transferase (COMT)) that metabolize (i.e., degrade/destroy) the neurotransmitters. The longer a neurotransmitter stays in the synapse, the more likely it is to be destroyed by one of these enzymes.

The Problem with Reuptake Inhibitors

Herein lies one of the major downsides to many medications that are traditionally used to alter neurotransmitter function – including selective serotonin reuptake inhibitors (SSRIs), selective norepinephrine reuptake inhibitors (SNRIs), norepinephrine reuptake inhibitors (NRIs) and tricyclic antidepressants.

These drugs block the reuptake of one or more neurotransmitters by binding with the reuptake transporter. This provides a temporary increase in the amount of neurotransmitter present in the synapse, which can provide short-term relief of symptoms associated with neurotransmitter imbalance, including depression, anxiety, focus, concentration and memory.

neurotransmitter reuptake

Figures taken from the National Institue of Drug Abuse website:

However, it also exposes these neurotransmitters to degradation over time by the MAO and COMT enzymes, which can cause further depletion in these neurotransmitter with time. For some people, this can occur in hours; with others it may take years. When it does happen, it usually appears that the drugs “quit working”.

neurotransmitter reuptake

Baseline During Reuptake Inhibition After Reuptake Inhibition (Over time)

Once this additional depletion has occurred due to the use of reuptake inhibitors, a person feels worse than they did when they originally started the medications and they often require more aggressive interventions in order to correct these imbalances.

Correcting Depletion Due to Reuptake Inhibitors

The only known way to increase the total amount of neurotransmitter in the system is through amino acid therapy. Amino acid therapy involves providing the body the building blocks that it needs to make more neurotransmitters. Over time, this will restore depleted neurotransmitter levels in the axon as well as provide sufficient neurotransmitter in the synapse to optimize function and eliminate symptoms due to neurotransmitter imbalance and/or neurotransmitter reuptake inhibition.