200 likes | 253 Views
Learning Objectives. You will be able to describe and evaluate why animals are used in lab studies when researching into drugs . You will be able to describe and evaluate how animals are used to research drugs .
E N D
Learning Objectives • You will be able to describe and evaluate why animals are used in lab studies when researching into drugs. • You will be able to describe and evaluate how animals are used to research drugs. • You will evaluate animal research in terms of both practical and ethical issues.
What do you think should go in the blanks? • According to the American Psychological Association, ___% of all psychological research involves the use of animals. • 90% of research involving animals uses ________ and _____. • __ % of animals used are primates. 8 rodents birds 5
Gene research • Mice have been used to find out how genes affect behaviour. • What are the advantages of using mice? • Breeding: mice breed very quickly, so inheritance can be investigated much quicker than in humans • Similarity: The arrangement of genes along their chromosomes is similar enough to humans to be meaningful.
Genes • Mice have been used to investigate the effect of genes of deafness. • Rats have been used to study Parkinson’s disease. • Researchers use drugs to replicate the symptoms of Parkinson’s disease, and then use gene therapy to reverse the symptoms.
The Nervous System • Rats have been used in investigations onthe effects of antipsychotic drugs on brain structure, and on the nervous system within the brain. The changes they have discovered are: • The Striatum: increased in size due to increased blood flow • Glial cells: Increased density in the prefrontal cortex • Synapses: Increased number of synapses and changes in the synapses
The Nervous System • Mice have been used to investigate changes in ________________ when they were put under stress. • Stress in an area that is often studied using animals. • Why? neurotransmitters
Studying functions of the brain • Research has been carried out into the way that antipsychotic drugs affect the brain and its nervous system. Most of the research has been carried out on ratsand the findings generalised to humans. • However, the research needs to be replicated in human because of the differences in brain structure and function between rats and humans. MRI scans can be used for this
Studying functions of the brain • As far back as 1950, Lashley was investigating brain function in rats by using ablation (removing part of the brain). • He systematically removed parts of the rat’s brain to see what affect it had on memory.
Studying functions of the brain • Rats have also been used to investigate the effects of sleep deprivation. • The rats not only became distressed, but died because of the deprivation.
Nagaraja & Jeganathan (2003) Examined the effects of acute and chronic conditions of overcrowding on free choice ethanol intake in rats
Aim: To examine the effects of overcrowding on ethanol intake in rats Method:A lab experiment with independent measures and two conditions
Conditions: Acute stressed - Overcrowded for 6 hours a day for a week Chronic stressed - Overcrowded continuously for a week
Both conditions had access to ethanol as well as other liquids
Results: Chronic stressed group showed increase in ethanol intake and ethanol preference over other liquids.
Evaluation The brains of animals are not the same as humans: results may not be generalisable Relatively small and easy to handle Some animals have very short gestation periods and short reproductive cycles Their genetic structure is not the same as humans: results may not be generalisable Pro-speciesism suggests that we ought to do all we can to protect our own species Animals in experiments are not in their natural surroundings, and therefore distressing conditions
Evaluation Some animals (mice etc) have a similar brain structure to humans Some animals (mice, rats etc) have a short lifespan (2 years) Drugs have been developed that could otherwise not have been developed. Some diseases (Parkinson's) have to be replicated in animals using drugs, and so may not be the same as the disease itself. Therefore, studies might lack validity Human lives are complex and factors rarely occur in isolation Some procedures have to be carried out daily Animals should be treated ethically . They are not sufficiently different from humans to be treated as objects
Evaluation – The knowledge obtained may also improve the lives of the species being tested on. Some procedures require strict control over the environment Using animals may not be credible Some procedures require accessing specific parts of the brain that might then be damaged. Procedures can be carried out on humans that can not be done on animals. E.g. ablation and leisoning Many animals feel pain
Arguments for and against using animals or humans for research 4 Against