Rohnert Park, CA (PressExposure) May 21, 2009 -- Before treating the addiction itself, therapists, psychologists, and doctors first try to learn how addiction works. It is said that addiction affects both the physical and the mental states of a person. But in most part, the mental state of a person is commonly the most affected of all.
Researchers from California drug rehab center have conducted numerous investigations using animal models and functional brain imaging on humans in order to define the mechanisms underlying drug addiction in the brain. This intriguing topic incorporates several areas of the brain and synaptic changes, or neuroplasticity, which occur in these areas.
Biological Basis of Drug Addiction
When examining the biological basis of drug addiction, understanding the pathways in which drugs act and how drugs can alter those pathways should first be observed. The mesolimbic system, also known to California drug rehab center professionals as the reward system, is characterized by the interaction of several areas of the brain with the drug. Here are some of the areas commonly affected by drug intake.
*The ventral tegmental area (VTA) consists of dopaminergic neurons which respond to glutamate. These cells respond when stimuli indicative of a reward are present. The VTA supports learning and sensitization development and releases dopamine (DA) into the forebrain. These neurons also project and release DA into the nucleus accubems, through the mesolimbic pathway. Virtually all drugs causing drug addiction increase the dopamine release in the mesolimbic pathway, in addition to their specific effects.
*The nucleus accumbens (NAcc) consists mainly of medium-spiny projection neurons (MSNs), which are GABA neurons. The NAcc is associated with acquiring and eliciting conditioned behaviors and involved in the increased sensitivity to drugs as addiction progresses.
*The prefrontal cortex, more specifically the anterior cingulate and orbitofrontal cortices, is important for the integration of information which contributes to whether a behavior will be elicited. It appears to be the area in which motivation originates and the salience of stimuli are determined.
*The basolateral amygdala projects into the NAcc and is thought to be important for motivation as well.
*More evidence from the California drug rehab center is pointing towards the role of the hippocampus in drug addiction because of its importance in learning and memory. Much of this evidence stems from investigations manipulating cells in the hippocampus alters dopamine levels in NAcc and firing rates of VTA dopaminergic cells.