Biological HLE

Value of animal models

Isolation, manipulation and measurement high levels of internal validity

Value of animal models

There are ethical and practical restrictions on the use of human bodies in research

Value of animal research models

Quick breeding cycles allow the study of hereditary and environmental factors

Assumptions of animal models

There are similarities between humans and animals because humans are mammals and both have been subjected to evolution

A form of living tissue that can respond in complex ways to their environment

British society of Animal Science: 3R’s

Refinement: focused and have realistic achievable aims.

Replacement: all a liable options replace animals should be explored

Reduction: reducing the amount of animals used to obtain meaningful results

How is hippocampus activity operationalised He et al

Abeta1-40 a peptide correlated with the formation of AD

MWM

A test of spatial learning for rats where milk is used to dilute the water their time discovering the platform is measured and it increases every time they search for it.

Rats injected with Abeta 1-40

Experienced lowed metabolic rate in hippocampus measured by a pet scan, they took longer to find submerged platform in MWM compared to control group

Value strength of He et al

Localises AD using pet scans which furthers understanding for a complex disease, direct manipulation of key variables that cannot be performed in humans,

Limitations value of He et al:

Alternative explanations studies with human participants: maguire et al and animal studies aren’t applicable to complex human behaviours

Ethical limitations of He et al:

Animals have to be anaesthetised and bulky equipment has be used for pet scanning and the obvious ethical limitations of giving rats Alzheimers

Pheromones

Mammals and insects produce chemical substances into the environment affecting the behaviour or physiology of others of its species

Hormones

Hormones are chemical messengers in the body responsible for regulating medium and long term changes in behaviour

Androstenone (AND)

A known pheromones to induce mating behaviour in female pigs (sexually dimorphic)

Dorries et al (1994)

Testing if female pigs are more sensitive to AND then male pigs, trained pigs to associate the ports with odors, rewarded with sugar both males and females were equally effective in distinguishing between the 3 odors. Female pigs were 5 times more effective at discovering AND.