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Biological Rhythms: Circadian rhythms Animal research and justification

Biological Rhythms: Circadian rhythms Animal research and justification . Aims To know the biological clock in control of the Circadian Rhythm To understand the difference between Endogeous Pacemakers and Exogenous Zeitgebers

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Biological Rhythms: Circadian rhythms Animal research and justification

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  1. Biological Rhythms: Circadian rhythms Animal research and justification Aims To know the biological clock in control of the Circadian Rhythm To understand the difference between Endogeous Pacemakers and Exogenous Zeitgebers To be able to evaluate animal research ethics/studies in regards RWA and justification

  2. Biorhythms • A biological rhythm is any change in a biological activity that repeats periodically. Often synchronised: Daily, Monthly and annual. Circadian = 24 hour cycle; S/W cycle Infradian = 24+ hour cycle; Menstrual cycle Ultradian = <24 hours; Sleep

  3. The SCN

  4. Justifying animal research using the CBA - Cost benefit analysis • Making decisions based on a CBA: • Quality of research • BUAV campaigns against Vivisection studies • Benefits to humankind • Suffering to animals • Can we generalise Costs Benefits

  5. Making decisions based on a CBA – cost benefits analysis: • Quality of research • BUAV campaigns against Vivisection studies • Benefits to humankind • Suffering to animals • Can we generalise

  6. Writing commentary for RWA and ethics • Research into circadian rhythms have huge real world application. • A common criticism of animal research is the unethical suffering caused by vivisection studies. • For example, .... deCoursey/ralph/morgan ..... • However, acost benefit analysis would suggest that the research is justifiable. • For example, the exxonvladez/chernobyl disasters .. .... occurred when people should have been sleeping. • Therefore this research must be completed to alleviate human suffering.

  7. Patricia DeCoursey (2000) • She removed/damaged the SCN in 30 chipmunks. The chipmunks were returned to their natural habitat. • After 80 days, significantly more of the SCN-lesioned chipmunks had been killed by weasels. • This was presumably because these chipmunks remained awake in their burrows and the weasels could hear the noise and were able to locate the chipmunks. IDEA: Cruel, Unethical, costs benefits analysis, generalisable, extrapolation, Rights, Speciesism, Equality, Respect, BUAV, Home office license, 3RRR’s

  8. Morgan (1995) Hamster research • He gave hamsters brain transplants of SCN from a mutant strain (which he bred) whose biological rhythms have a shorter cycle. • The recipients adopted the same activity cycles as the mutant strain. • The finding that animals transplanted with the SCN adopts the same activity patterns as their donors, along with the fact that the circadian rhythm cannot be manipulated beyond certain limits, suggests that bodily rhythms are primarily endogenous. • IDEA: Cruel, Unethical, costs • benefits analysis, • generalisable, extrapolation, • Rights, Speciesism, Equality, • Respect, BUAV, Home office • license, 3RRR’s

  9. Ralph (1990)Hamster study • Aim: To show that the SCN generates the circadian rhythm in mammals. • Sample: hamsters, with a genetic abnormality affecting their circadian cycle that resulted in a 20-hour circadian cycle, rather than a 24-hour one. • Method: Their SCNs were removed and placed in the brains of a group of hamsters with a normal 24-hour cycle. • Result: The experimental group shifted to a 20-hour cycle. • Conclusion: the hamsters’ circadian cycle was regulated by the SCN. When normal hamsters were given an abnormal SCN they developed an abnormal circadian cycle. • IDEA: Unethical, generalisable, extrapolation, • BUAV, Speciesism, Ralph (1990) also transplanted an SCN from a free running (25 hour) hamster into the mutants; who adopted a 25 hour rhythm. The mutant gene was tau which caused the 20 hour cycle. Showing how genes affect behaviour.

  10. RWA Justification of animal research: Working when we should be sleeping!Using SCN research to help remove Human error from shift work • Negative effects of sleep deprivation • e.g. decreased attention • slowing of reasoning skills • impaired reaction could have serious consequences on the ability to do work or drive safely. Possible justification for animal research Practical application of Psychology in the real world

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