• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Discuss the evidence for a dopaminergic system that is involved in reward and drug addiction.

Extracts from this document...

Introduction

Hemis no: 127844 Word Count: 1,962 PS2060B Biological Psychology Discuss the evidence for a dopaminergic system that is involved in reward and drug addiction Most drugs affect the brain and behaviour by changing synaptic transmissions (Rosenzweig 1999). In order to discuss the evidence for a dopaminergic system that is involved in reward and drug addiction, we need to establish the relationship that a dopaminergic system has with drug reward and drug addiction. In essence when we are discussing a dopaminergic system we are making reference to neurotransmitter systems. The intricacies involving the brain, neurochemically have become more prevalent through processes such as immunocytochemistry. Through such processes we are able to locate substances within the nervous system as well as identifying neurotransmitters. Dopamine and seratonin are neurotransmitters, which are integral in relation to drugs whether it is used for drug reward or drug addiction. This essay will focus on such neurotransmitters in order to discuss evidence for a dopaminergic system that is involved in reward and drug addiction. Neurotransmitters such as dopamine and seratonin originate from the family of monoamines. Monoamines are classified into to groups, catecholamine and indolemine. Dopamine is within the catecholamine class and seratonin along with another prominent neurotransmitter melatonin are from the indolemine class. Dopamine is essential because it has an impact on drugs and in relation to the question it has an impact on drug addiction and drug reward. Dopamine affects brain processes that control movement, emotional response, and the ability to experience pleasure and pain. ...read more.

Middle

(Kalat:66). Drugs such amphetamines and cocaine are important as it will provide evidence for the relationship between drugs and the dopaminergic system. Amphetamines stimulate the dopamine synapses by increasing the activity of dopamine from the presynaptic terminal as the terminal allows it to reabsorb the dopamine after its release (Giros et al 1996). Cocaine has a different effect on dopamine levels as it blocks this reabsorbing of dopamine thus prolonging the effects. Although the effects are temporary the drugs will actually increase the level of dopamine accumulated in the synaptic cleft. Drugs such as Amphetamines and cocaine are all self-stimulated drugs. To support the idea of increasing and decreasing the levels of dopamine, Olds and Milner carried out an experiment involving the use of rats. The experiment on rats was conducted in Skinner boxes, with electric levers for stimulation. The stimulation acted as a reinforcement measure. Olds and Milner found that the rats worked very hard in order to stimulate themselves, as much as 2000 times an hour till the rats faced exhaustion. Olds in particular believed that the rats kept on administering the stimulations because it triggered areas of limbic system to stimulate. Olds Milner conducted further experiments and found that the stimulations were in fact took place in axons which release dopamine. This does suggest some evidence of drug use whether it is on a reward or addiction purposes with a dopaminergic system. There also needs to be a distinction between the different types of drugs. ...read more.

Conclusion

The fact that GABA and glutamate are so widely present makes it likely that they will be altered during drug addiction. This also makes it difficult to treat addiction with drug therapy without causing side effects. So as well as dopamine, other neurotransmitters interact with drugs thus proving more evidence of a dopaminergic system that involves drug reward and addiction. Drugs can interfere with just about every step in the work of neurotransmitter. Each receptor is designed to bind only a certain neurotransmitter. A way to illustrate the discussion could be that the drug acts like a key and if it is structurally similar to the neurotransmitter then it will fit the receptor, which acts as the lock. In this way drugs can damage your intellectual property by blocking nerve impulses, preventing neurotransmitters from getting where they are supposed to be, or producing too many or too little neurotransmitters. As a result, neurons may be over stimulated or not stimulated at all, crippling the nervous system's ability to carry out its functions. There has been plenty of evidence to suggest a dopaminergic system involving drug abuse and reward. Dopaminergic agonists such as cocaine have shown us that through drug use, there is an increase of dopamine, which is brought on by the sensation felt by the drug. It is essential that we remember that the relationship between drugs and a dopaminergic system is reversible but there is substantial evidence to suggest that drug usage has an effect with a dopaminergic system which is useful in explaining the use of drugs to reward and drug addiction. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our University Degree Pharmacology section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related University Degree Pharmacology essays

  1. In this lab report I am going to investigate the neutralising behaviour of six ...

    The calcium carbonate also counteracts the laxative effects of the magnesium. However it slows down bowel movement and so can cause constipation. Most antacids that contain magnesium are paired with either aluminium or calcium carbonate so counteract its laxative properties.

  2. Comparing the dissolution of tablets and capsules. The purpose of this experiment ...

    Anadin (�1.99 : 12 p per tab) 500mg paracetamol, Croscarmellose (super disintergrant) sodium, povidine(viscosity enhancer), pregelatinised maize starch(disintergrant), stearic acid (lubricant), hydroxypropyl methyl cellulose (E464) (solution binder), polyethylene glycol(solution binder). Paracetamol galpharm (�0.16p: 1p per tab), 500g paracetamol, Pregelatinised maize starch BP(disintergrant),, sodium metabisulphide BP and magnesium stearate BP(lubricant).

  1. Pathophysiology of health and disease

    This means that we have some problems here but we can identify what the problems are by the results provided. Red blood cells are the most common type of blood cell and the vertebrate body's principal means of delivering oxygen to the body tissues via the blood.

  2. Give an account of how the monoamines act as transmitters and their roles in ...

    Whilst indirect evidence for this position exists, for example from studies of rats which have been modified to have no reuptake transporters for transmitters; a singularly genetic origin of disorders such as schizophrenia and depression is precluded by psychological variables mediating symptoms.

  1. Pharmacology. The use of co-beneldopa and selegiline in the treatment of Parkinsons disease

    it is a reaction to certain drugs, or a particular drug or a number of drugs (Neal, 1992). This may be caused by a deficiency of the drug or a patient may have a condition than can affect the drug (Neal, 1992).

  2. Biosimilars and recombinant drugs

    medical costs against the policy of fixed payment and hence has become a major financial consideration for many patients (Thomas et al., 2008). * Clinical, ethical sense in covering drugs: Many drugs are treated the same way regardless of the activity it provides.

  1. The aim of this experiment was to formulate and manufactured Aspirin 75mg tablets in ...

    The physically modified properties of the filler blinders demand tight control. There is a lack of content uniformity for low dose drugs. The accumulation of dust is also an issue. Wet Granulation Wet granulation is the most commonly used manufacturing process for oral dosage forms.

  2. Analysis of 3 Unknown Chemicals

    After an elemental analysis was performed, the identity of the unknown was confirmed using IR spectroscopy, 1H NMR analysis, and mass spectra analysis. Based on the preliminary results from the physical characteristics and solubility tests, the chemical tests chosen for unknown #35C were the Lucas Test (Pavia, p.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work