Cocaine addiction can occur due to several different factors. First of all, repeated cocaine exposure alters the dopamine-producing cells in the brain. This in turn turns conscious memories into near-compulsions. Secondly, repeated cocaine exposure also slows down glucose metabolism. These three factors combine to create an addiction.
Mesolimbic dopamine pathway
In humans, the mesolimbic dopamine pathway is activated by the drugs we abuse. Dopamine is a neurotransmitter that facilitates the sensation of euphoria. It is also responsible for the enabling effect of psychostimulants. These drugs can lead to a high-intensity euphoric state, and hence addiction.
The transition from occasional drug use to addiction is complex, involving neuroplasticity in different brain structures. It may start with changes in the mesolimbic dopamine pathway and then cascade through the orbitofrontal cortex and the ventral striatum to the prefrontal cortex. This delineation of neurocircuitry can serve as the basis for searching for neuroadaptations responsible for cocaine addiction.
Basal ganglia
The basal ganglia is an area of the brain responsible for controlling emotions. It receives signals from various regions, including the striatum and the globus pallidus. The prefrontal cortex receives these signals, and then modifies them using circuitry in the basal ganglia.
The basal ganglia is divided into four distinct structures based on their location in the brain. The substantia nigra is in the middle of the brain. Its granule cells produce dopamine. It also maintains the balance in the striatal pathway.
Basal ganglia slows glucose metabolism
The basal ganglia are regions of the brain that control glucose metabolism and dopamine production. Dopamine-related brain structures are most commonly found in the basal ganglia, whereas dopamine-related structures are less commonly found in parietal cortices. It is thought that dopamine's neurotrophic effects may counteract the injurious effects of inflammation, which is caused by the activation of microglial cells and astroglial cells.
Studies have found that the basal ganglia is involved in the processing of reward in humans. In addition, this area has been associated with cocaine addiction. The basal ganglia may influence the reward-dependent learning processes that occur in the brain.
Glutamate plays a role in cocaine addiction
The chemical glutamate is present in the brain in large amounts and is crucial to many functions, including learning, memory, and synaptic plasticity. It is a neurotransmitter that also affects how we react to alcohol, drugs, and other stimuli, as well as our overall physical and emotional well-being. However, when glutamate levels go haywire, it can lead to addiction. When an addict associates a positive experience with a drug, his or her brain reacts by constantly seeking that drug.
In order to better understand the connection between glutamate and addiction, scientists have looked at the brain of cocaine and opiate-dependent adults. They have found that individuals with a particular gene mutation were more susceptible to addiction. This discovery supports the hypothesis that glutamate plays a role in cocaine addiction.
Prefrontal cortex abnormalities are implicated in cocaine addiction
The brain's prefrontal cortex regulates higher-order executive functions, including learning and reward. This region has also emerged as a key driver of cocaine-seeking behaviors in animal addiction models. In rodent cocaine addiction models, abnormalities in signaling between the prefrontal cortex and the habenula affect drug seeking and withdrawal behavior. This circuit is also implicated in the neuropathological effects of drug use and relapse.
These abnormalities in the prefrontal cortex are correlated with increased activation and connectivity to drugs. They are thought to contribute to the inability of the addicted person to change their habits and learn from the consequences of their drug use.
Glutamate affects dopamine
Glutamate is the most abundant excitatory neurotransmitter in the brain. It plays a critical role in learning and memory, and it's essential for synaptic plasticity. When glutamate levels are too high, addiction results. This occurs when the brain associates a positive experience with the drug, and then becomes obsessed with seeking it out.
It's believed that the glutamate in cocaine, amphetamines, LSD, and alcohol interfere with serotonin signaling. The serotonin-making neurons in the brain send signals to almost all parts of the body, including the spinal cord. They play an important role in mood, body temperature regulation, and appetite. Serotonin is linked to many mental health disorders, and many medications have been developed to boost its levels in the brain.
