Pharmacology course work - Essay Example

1. two types of neuroglial cells. Astrocytes and Oligodendrocytes 4 marks 2. two neurotransmitters which are amino acids, and two which are monoamines. Amino acids: (i) Glutamate (ii) Aspartate Monoamines: (i) Dopamine(ii) Adrenaline 8 marks2. What is an inverse agonist?Inverse agonists are ligands that like agonists bind to the same active receptors but produce an opposite effect to that of an agonist by stabilize the receptors thereby reducing their activity. 4 marks4.

Which statement is not correct?a) Benzodiazepines potentiate the action of GABA on GABAAreceptors.b) Valium sensitises the GABAA receptor to GABA.c) Benzodiazepines cannot activate GABAA receptors.d) Barbiturates activate GABAA receptors.The incorrect statement is _b____ .2 marks5. With regard to neurotransmission, what do the letters EPSP stand for?Excitatory Postsynaptic Potential2 marks6. Indicate whether each statement relating to general anaesthetics is true orfalse by ticking the appropriate box.

General anaesthetics:True FalseBlock sodium channels FalseExhibit potency which correlates with their lipid solubility TrueInhibit excitatory (e.g. glutaminergic) receptors. TrueActivate inhibitory (e.g.GABA) receptors TrueHyperpolarise neurones by blocking K+ channels False5 marks7. Fill in the blanks below.Carlsson hypothesized that schizophrenia is the result of excessive___dopamine____________________ergic transmission in the brain. Consequently, anexample of a “typical” antipsychotic drug is __Perphenazine____________________, which acts by blocking __Dopamine D1 and D2 receptors__________________ receptors (specify the subtype).6 marks8. Fill in the blanks below.

Withdrawal (abstinence) symptoms in drug dependency are associated withreduced ___________dopamine____________ergic transmission in a localised area ofthe brain called the ______nucleus accumbens_______________________ otherwise known as “the pleasure centre” of the brain.4 marks9. Give three abnormalities most evident in the brains of Alzheimer’s diseasepatients, post mortem.At post mortem Alzheimer’s disease is characterised by neuronal loss, neurofibrillary tangle formation in the neocortex and hippocampus and specific presynaptic markers of cholinergic system appear to the uniformly reduced.

6 marks10. Briefly describe the role of the Mini Mental State Examination (MMSE),indicating how the scoring works.This is a series of questions and tests which is used by clinicians for diagnosing dementia and to assess its severity and progression. If all the answers are correct a maximum score of 30 can be obtained. A score of 27 and above is considered normal while score below that will require further assessment for any mental impairment. 4 marks11. Define two of the following movement disorders: akathisia, bradykinesia,dystonia, tardive dyskinesia.

Akathisia is a condition that is characterised by motor restlessness, ranging from anxiety to inability to sit or lie quietly or to sleep. It is a common side effect of neuroleptic medications. Dystonia is a movement disorder characterized by sustained muscle contractions which results in writing or twisting movements and unusual body postures. 8marks12. Give two examples of neurotransmitter receptors which are ionotropic(Class I).Nicotinic acetylcholine receptors and glutamate receptors4 marks13.

Name three main classes of glutamate receptor (abbreviations areacceptable).The three classes have been named after selective agonists which bind to these receptors such as NMDA, AMPA and KA. 6 marks14. Complete the table below, filling in all the blanks, giving one example of eachof the five main classes of hallucinogens.Pharmacological class ofhallucinogen Example:Anti-cholinergic - Atropine Catecholamine-like - MescalineSerotonin-like - Lysergic acid diethylamideNMDA antagonists - SelfotelOpioid kappa agonist - Ketazocine10 marks15.

Which neural pathway has a role in movement control and is adverselyaffected in Parkinson’s disease?Parkinson’s disease is characterized by profound and selective loss of nigrostriatal dopaminergic neuronal pathway2 marks16. a) Name two of the five main types of anxiety disorder.Generalized anxiety disorder and Obsessive compulsive disorder4 marksb) Name two of the four main classes of drugs used to treat such disorders.Anti-depressants and anti-anxiety drugs4 marks17. Name four acute effects of opiates.

Respiratory depression, opiod-induced hyperalgesia, increased mortality and hormone imbalances8 marks18. a) What is Schildkraut’s theory of affective disorders?The catecholamine theory of mood proposed by Schildkraut suggests that depression is associated with a functional deficiency of noradrenaline at receptor sites within the brain and mania is associated with an excess of noradrenaline at central receptor sites. 5 marksb) Give one example of a second generation anti-depressant drug, indicatingits mode of action.

Bupropion is an example of second generation anti-depressant and its main mechanism of action is known to be dopaminergic and noradrenergic. 4 marks1. For each neurotransmitter shown below (a - f), select the family to which itbelongs from the following list:quaternary amine, monoamine (catecholamine), secondary amine(catecholamine), amino acid (moncarboxylic acid), amino acid (dicarboxylicacid), polypeptide, opioid pentapeptide.Neurotransmitter Familya) Ach - cholinergic neurotransmitterb) BDNF neurotrophinc) GABA amino acid (dicarboxylic acid)d) Glutamate amino acid (monocarboxylic acid)e) Dopamine monoamine (catecholamine)f) Met-enkephalin opioid pentapeptide3 marks3.

For the following passage, delete the incorrect words in the phrases shown inbold font:A presynaptic alpha 2 receptor on a serotonergic neuron is called aheteroreceptor . It reducesneurotransmitter exocytosis by inhibiting the opening of Ca2+ ionchannels.3 marks4. In each case, give one example of:a) a natural narcotic: ___________opium___________________b) a semisynthetic opioid: _______hydrocodone_______________________c) a synthetic opioid: ____________Fentanyl__________________3 marks5. With reference to one named neurotransmission mechanism, how doesethanol mediate its action as a CNS depressant?

Recent studies have shown that depressing effects on the CNS by ethanol is mediated by GABA which is a primary inhibitory neurotransmitter in the CNS. Activation of the GABA receptors by GABA decreases neuronal excitability. 2 marks9. Which statement is not correct?a) Valium sensitises the GABAA receptor to GABA.b) Barbiturates activate GABAA receptors.c) Benzodiazepines cannot activate GABAA receptors.d) Benzodiazepines potentiate the action of GABA on GABAAreceptors.The incorrect statement is __c__ .1 mark14. Name three drugs/therapies that are currently in clinical trials (phases 1-3) forthe treatment of Alzheimer’s disease.

AC 1204 for people with mild to modertate diseaseAdvanced deep brain stimulation of the fornix in people with mild diseaseAVP923 for treatment of agitation in Alzheimer’s disease3 marks2. Broadly speaking dopamine receptors fall into 2 receptor subtypes; brieflyexplain why.The D1 family of dopamine receptors is coupled to a G protein which activates adenylyl cyclase while the D2 family of dopamine receptors is coupled to a G protein which inhibits adenylyl cyclase.2 marks6. Abuse of which substances (state one in each case) might be treated with:i) mecamylamine _____nicotine antagonist used in smoking cessation programs___________ii) disulfiram _______used to treat chronic alcoholism by acute sensitivity to alcohol_________2 marks7.

What is the basis of the dexamethasone suppression test for depression?The test is used as a measure of the adrenal response to ACTH.3 marks8. Give one example of each of the following, indicating in each case themechanism of action:a) a first generation anti-depressant drug;tricyclic antidepressant: amitriptylineb) a second generation anti-depressant drug.Selective serotonin reuptake inhibitors: Fluoxetine4 marks10. There are four pharmacological strategies to treat anxiety disorders. Nametwo of these, and give one named example of a drug for each.

Selective serotonin reuptake inhibitors: escitalopramSerotonin and noradrenaline reuptake inhibitors: venlafaxine4 marks12. What are the three phases of schizophrenia? Briefly describe the behaviouralsymptoms exhibited in each phase.Prodromal phase : lose interest in usual pursuits, become easily confused, concentration problems, listless, apthetic and a preference to be aloneActive phase: experience, delusions, hallucinations, marked distortions in thinking and disturbance in behaviour and feeling.

Residual phase: people may be listless, concentration problems and general feeling of withdrawal3 marks13. Antipsychotic drugs used in the treatment of schizophrenia are split into twocategories; typical and atypical.a) Give one named example for each category.Typical antipsychotic drug: ChlorpromazineAtypical antipsychotic drug: Clozapine2 marksb) What is the main problem associated with the use of the typicalantipsychotic drugs?These drugs carry a high risk of side effects some of which could be very severe.2 marks15. The glutamate NMDA receptor is the target of memantine, a drug used in thetreatment of Alzheimer’s disease.

How is this receptor implicated in thepathogenesis of Alzheimer’s disease?Increased stimulation of the NMDA receptor is implicated in the increased free radical production by which it potentiates the toxicity of several peptides and causes neuronal damage and impairment of synaptic plasticity. 3 marks16. The following questions refer to the symptoms associated with Parkinson’sdisease (PD).a) What are the four main motor symptoms of PD and brieflymention the traits of these symptoms.They are:Shaking or tremor that involves involuntary shaking of the arms, legs, hands, jaw or tongueSlowness of movement which is also referred to as bradykinesiaStiffness or rigidity of the arms, legs or trunkPostural instability that involves trouble with balance and possible falls. 4 marksb) Name two non-motor symptoms associated with PD.

Mood disturbances and apathy and depression are the two symptoms1 mark17. What is 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and why has itbeen useful in the understanding the pathogenesis of Parkinson’s disease?MPTP is a model in which the neurotoxin MPTP is employed. This has a competitive advantage over other models as when it causes intoxication it induces a syndrome virtually identical to Parkinson’s disease in humans. 3