The Application of Metabolic Pathways on Biotechnology
Cocaine
"Blow, C, Coca, Coke, Crack, Flake, Snow..." These are just a few of the most popular street nicknames for the psychoactive drug known as, Cocaine.Widely popular in the 80's and 90's, Cocaine was originally derived from the leaves of the Erythroxyloncoca bush. [1] [2]
In the Brain
Cocaine works by interfering with the levels of dopamine within the regions of the midbrain known as the Ventreal Tegmental Area (VTA) and the Nucleus Accumbens. The VTA is responsible for many of the reward system's responses such as: motivation, cognition, addictions, intense feelings regarding love, and orgasms. In addition, the VTA is the site of origin for dopaminergic cell bodies. The Nucleus Accumbens also deals with emotions of pleasure and fear. [2] [5] [6] [7] [8]
Zooming into this area between the Nucleus Accumbens and the VTA, Cocaine acts specifically on the Mesoaccumbens dopamine pathway. [3]
Normally, without the presence of Cocaine, a transmitting neuron would release the neurotransmitter, dopamine, into the synapse. The dopamine would then bind to the dopaminergic receptors of the receiving neuron and send its signal or message to that neuron. After this process is accomplished,it is the role of the Dopamine Reuptake Transporters to pump the remaining dopamine molecules out of the synapse. [2] [3] [4] [9]
Active Dopamine Transporter
Dopamine Receptor
Dopamine
Blocked Dopamine Receptor
Cocaine
However, this process is interrupted once Cocaine is taken into the body. As depicted in the picture above and below, Cocaine binds to the dopamine reuptake transporters and inhibits their functioning. By blocking the removal of dopamine from the synapse, the neurotransmitter begins to rapidly accumulate in the synapse.This increasing level of dopamine continously stimulates the neuron, causing rapid firing at an amplified level, and thus leading to a sense of euphoria. [2] [3] [4] [9]
The image above depicts two different brains. The one on left is cocaine free, while the one on the right has implements of the drugs. As shown, the use of cocaine severely reduces the receptor availability of dopamine.
Interesting Fact
While Cocaine is reknown for affecting the dopaminergic pathways in the brain, the drug also impacts the pathways of Serotonin and Norepinephrine in a similar fashion.
Another diagram depicting how Cocaine works at the synapse of the neuron.