Addictions Neuroscience : Heroin and other Opioids
Opioid addiction, dependence, and tolerance are signs of drug abuse manifesting in brain changes. Patients suffering from addictions can be helped to understand that illnesses related to the addiction has a biological basis and the use of these drugs is purposely meant to manage acute pain and chronic disorders. Therefore, an addicted individual requires continuing using the drugs to avoid brain abnormalities and withdrawal syndromes. Notably, the defects that lead to addiction are consequently, long-lasting, complex and wide-range.
Thus, it requires a motivational mechanism which may result in positive reinforcement. There are neurobiological mechanisms such as the use of neurochemical elements that are usually involved in stress and reward (Koob & Le Moal, 2008). The extended amygdala and the ventral striatum are usually dysregulated in addiction such that they convey to the opponent a motivational process which can be used to drive dependence.The mechanism of opioids mimics endorphins functionality which are endogenous opioid-like compounds by facilitating the activation of prevalent neurotransmitters like gamma-aminobutyric acid throughput the brain (Sherman, 2017). The mechanism regulates the activities of the positive brain reinforcement.
How it works
Opioids and heroin inhibit reuptake of dopamine, norepinephrine, and serotonin which leaves the neurotransmitters in the synapse. The action results in an effective change on the receptors which can enhance the behavior of the agent. Incentive salience also leads to positive reinforcement whereby the stimulus increases the possibility of response causing a hedonic state (Koob & Le Moal, 2008). The effect has been drawn on the observation that even animals work hard to find a drug in the absence of the imposed motivational state like drug withdrawal, water deprivation, and food. In other words, heroin and other opioids function by usurping the brain’s salience system.
Koob, G. F., & Le Moal, M. (2008). Neurobiological mechanisms for opponent motivational processes in addiction. Philosophical Transactions of the Royal Society of London B: Biological Sciences, 363(1507), 3113-3123.
Sherman, C. (2017). Impacts of Drugs on Neurotransmission. Drugabuse.gov. Retrieved 22 September 2017, from https://www.drugabuse.gov/news-events/nida-notes/2017/03/impacts-drugs-neurotransmission