Refraining from using drugsRefraining from using drugs is one behavior that is achieved by performing a series of actions that are associated with the brain. This decision is mainly goal-directed and technically requires an incentive in order to achieve such status. It should be understood that the environment is filled with different forms of stimuli and each of these exerts a particular effect on each individual. The effect of each of these environmental factors, alongside the genetic constitution of an individual, influences whether an individual will be using drugs or will refrain from using these.
The concept of performing a certain behavior such as refraining from using drugs is a specific action that is achieved from a process that involves trial and error. This behavior is focused on a certain goal and any actions conducted are thus geared towards achieving this goal. The most critical aspect of this behavior is the repetitive nature of the action, which largely influences the efficiency of the actions towards achieving the goal. It has been established that extensive learning of a certain action serves as an instrumental action in achieving a goal, such as refraining from using drug. This training may still be sensitive to factors in the environment or in the physiological condition of the body, but through the use of reinforcements, these various stimuli can still be overcome. Neurological research has described that training the mind and choosing a certain behavior such as refraining from the use of drugs involves a number of neuroanatomical pathways (Yin and Knowlton, 2004). Performance of a battery of actions that is geared towards achieving a goal such as refraining from drugs is the dependent on the cortico-basal ganglia, which connects to the dorsomedial striatum of the brain (Yin et al., 2005).
In addition, the cortico-basal ganglia are also connected to the pre-limbic cortex, as well as the mediodorsal thalamus. Habits are thus developed through the control of the sensorimotor striatum as well as the infralimbic cortex, of the brain (Nelson and Killcross, 2006). For several years, the molecular switch between a habit such as addiction and an action that is geared towards a certain goal has been under investigation by neurologists and psychologists. For example, the use of amphetamine results in the brain’s sensitization to this particular reagent and the development of the habit of using this chemical is quickly achieved. In neuoranatomical terms, amphetamine use results in the increase in the density of nerve cells of the dorsolateral striatum of the brain, which in turn results in the formation of the habit, which is also simply called an addiction. On the other hand, the action of refraining from using drugs involves the same part of the brain, yet there is no increase in density of the nerve cells of the dorsolateral striatum, thus allowing an individual to achieve his goal of staying drug-free. The behavior of staying free from drugs is due to certain molecules that are inherently produced by nerve cells in the brain. For example, the neurotransmitter dopamine is generally secreted by neurons of the striatum of the brain.
In addition, a protein known as the dopamine transporter is responsible in moving this chemical across synaptic connections of the neurons (Ito et al., 2004). The most likely scenario of a healthy drug-free individual thus involves the normal transport of dopamine through the synapses, resulting in a calm and happy individual. On the other hand, an individual who is dependent on drugs, such as amphetamine, experiences from a dysfunctional dopamine transporter and thus there is an imbalance in the transport of the dopamine neurotransmitter through different neurons. It should be understood the amphetamine targets the dopamine transporter, inhibiting this protein from transporting neurotransmitters from one neuron to another.
Another part of the brain that is characteristically employed in the condition of staying free of drugs is the prefrontal cortex (Hitchcott et al., 2007). This region of the brain also receives input from the dopamine neurotransmitters, favoring a particular behavior such as that of refraining from the use of drugs. Dopamine thus plays an important role in the mental health, as well as drug condition, of an individual. This neurotransmitter is also strongly associated to another mental health condition known as depression.
The lack or absence of dopamine transport between neurons results in the state of depression. Interestingly, the same condition is attained during administration of cannabinoids, such as that from marijuana. There are particular receptors in the brain that are responsible is receiving cannabinoid signals and once this stimulus is stopped, the individual experiences a negative feedback response, which is also known as addiction. In a genetic assay involving mouse models, the CB1 gene, which is associated with cannabinoid interaction, was knocked out and these organisms were compared to wild-type mice with regards to learning a specific behavior that was associated with reinforcements (Hilario et al., 2007). Their study showed that repetitive learning activities decreased the likelihood that any changes in the immediate environment would perturb the choices of the mice. This habitual training, coupled with reinforcements such as rewards when behaving properly, showed a strong deference to novel inputs such as drugs. It is thus possible that an individual who refrains from using drugs is highly trained to such behavior and is constantly receiving reinforcements in this immediate environment.
In drug addiction, there is a constant activation of the dopamine receptors of the brain (Wickens et al., 2007). It has earlier been established that dopamine receptors are associated with learning new habits. Once a new action is repeated several times, the need for dopamine to facilitate learning the new habit diminishes, as the lessons is eventually imprinted in the brain of the individual. Thus, during the initial stages of learning, there is a markedly high level of dopamine being generated by the neurons, but through continuous and repetitive actions, the dopamine level in the brain decreases because the brain has also been trained to the new lesson.
The same conditions of learning are established in drug addiction, wherein the repetitive introduction of an illegal drug teaches the brain to acclimatize to its effect and thus the amount of dopamine in the brain drops down through time. When this stage is achieved, the drug addict has to administer a larger dose of the drug into his body in order to achieve the desired dopamine effect, not knowing that once day, the dose will be too high for the entire body to handle. According to Ito et al., (2002), the behavior of seeking a certain drug is learned by the brain through continuous and progressively introduction of the reagent. This neural imprinting mainly occurs in the neurons located in the substantia nigra of the cortical region of the brain.
It should be understood that this habit can still be modified by presenting a new lesson to the brain and that is a condition that does not involve the use of drugs. Refraining from the use of drugs thus involved a set of actions that are designed in order to achieve a goal (Valentin et al., 2007). In addition, this set of actions are learned by an individual so that when a specific change occurs in his immediate environment or to himself, he will not easily be enticed to modify his behavior and possibly partake of the novel stimulus such as drugs. The associated control, as well as attention an individual provides to stick to his goal of staying away from drugs involves a significant amount of energy, yet it is still possible to succeed from such struggle. It has been observed that when an individual is dominantly living in an environment that is devoid of drugs, then it is more likely that this individual will not adapt a behavior of partaking of this illegal drug.
In addition, the habitual action of staying drug-free is most likely maintained by an individual because this has been trained in his mind. The role of the brain in drug addiction can also be observed among individuals who are subjected to withdrawal from using drugs. This drug-seeking behavior apparently increases once the habitual drug is withdrawn from their reach. Since the use of drugs has been trained into their brains, it is a common reaction of drug addicts to seek sources of the drug in their environment, in order to maintain their mental condition. For example, morphine is employed to remove any sensation of pain in an individual. Morphine is administered to hospital patients who experience pain, yet can also be illegally administered by drug addicts.
In the case of morphine drug addiction, a Pavlovian response associated with pain is learned by the brain, wherein any uncomfortable sensation is referred to as pain and that there is a need to use morphine to remove that actual pain. In this case, the amygdala is responsible for the craving, as this part of the brain sends out protein kinases and cyclic adenosine monophosphate (camp) element-binding proteins that interact with morphine. There is also a frequency-response gradient that exists between the brain’s reaction and the drug that is administered to the body. In a study conducted by Li et al. (2008), which involved testing the response of rats to opium, the behavioral response or craving for opiates was stronger when the drug was administered daily for 2 weeks, even at very low doses. On the other hand, another setup involving a single high dose of opiates did not result in a markedly high degree of craving. It has been suggested that the phoshorylation of proteins involved in the signaling pathway used by opiates results in such behavior, including the inhibition of the central amydala.ReferencesHilario, M.
R.F., Clouse, E., Yin, E.H. and Costa, R.M.
(2007). Endocannabinoid signaling is critical for habit formation. Frontiers in Integrative Neuroscience, 1, 1-12.Hilário, M.R.F.
and Costa, R.M. (2008). High on habits.
Frontiers in Neuroscience, 2, 208-217.Hitchcott, P.K., Quinn, J.J.
and Taylor, J.R. (2007). Bidirectional modulation of goal-directed actions by prefrontal cortical dopamine. Cerebral Cortex, 17, 2820-2827.Ito, R., Dalley, J.W.
, Robbins, T.W. and Everitt, B.J. (2002).
Dopamine release in the dorsal striatum during cocaine-seeking behavior under the control of a drug-associated cue. Journal of Neuroscience, 22, 6247–6253.Li, Y.Q., Li, F.Q., Wang, X.Y.
, Wu, P., Zhao, M., Xu, C.M., Shaham, Y. and Lu, L. (2008).
Central amygdala extracellular signal-regulated kinase signaling pathway is critical to incubation of opiate craving. Journal of Neuroscience, 28, 13248 –13257.Nelson, A. and Killcross, S. (2006).
Amphetamine exposure enhances habit formation. Journal of Neuroscience, 26, 3805–3812.Valentin, V.V.
, Dickinson, A. and O’Doherty, J.P. (2007). Determining the neural substrates of goal-directed learning in the human brain.
Journal of Neuroscience, 27, 4019–4026.Wickens, J.R., Horvitz, J.C.
, Costa, R.M. and Killcross, S. (2007). Dopaminergic mechanisms in actions and habits. Journal of Neuroscience, 27, 8181– 8183.Yin, H. H.
, Knowlton, B. J., and Balleine, B. W. (2004). Lesions of dorsolateral striatum preserve outcome expectancy but disrupt habit formation in instrumental learning.
Europeran Journal of Neuroscience, 19, 181–189.Yin, H. H.
, Knowlton, B. J., and Balleine, B.W. (2005a). Blockade of NMDA receptors in the dorsomedial striatum prevents action-outcome learning in instrumental conditioning. Europeran Journal of Neuroscience, 22, 505–512.