Animal studies Flashcards
why were animal studies so important in the past
Well thats where we got most of our information from on how the mind worked. either animal or lesion studies.
What limitations do both animal and fMRI research share?
- The nature of the studies are not realistic
- the way the studies are designed they need to include long delays – doesn’t exactly mirror the cognitive processes you are studying
- can only be a correlational technique
why do we see less animal studies today?
- The number of animal studies is way smaller now than the number in the past, 20/40 years ago. This is because techniques in humans have refined so much*
- linked to one of the R’s - refinement. if you dont need ot use the animal dont. development of techniqes mean they can be applied to humans.*
Why use animals if we wanna study the minds of humans?
- Animals = more simplified models of the human brain. Studying them is easier
- Animals have shorter lifespan. We can study the onset, development and eradication of disease or other things across as the animal grows
- Convenient – can get hold of them, do stuff
- Allows for genetic manipulation –manipulate nervous system, genes, hormones etc… something we couldn’t do in people.
- can control experiments with animals in a way you couldn’t with humans -Animals don’t know they’re in an experiment -No demand characteristics. No wondering “what are they doing this for”?
- Have no symbolic system of representation – humans we have language, but animals don’t have equivalent language capabilities (both strength and weakness)
Why shouldn’t we use animals?
- Yes similar to humans but not the same, physiological systems will be different
- Human brains are different to animal brains
- Animals require months of training to perform a task a human could learn in 5 minutes. Once they are trained they often spend months performing the tasks while recordings are made
- Expensive
- Ethical reasons - may distress animals.
why shouldn’t we use animals: different physiology to humans
- genetic variations exist between humans and other animals; and also between different strains of the same species.
- Pharmacological research might not work – drugs may have a heterogenous effect on humans vs animals. Not the same for both.
Why shouldn’t we use animals: overtrained
- Animals require months of training to perform a task a human could learn in 5 minutes.
- Once trained they often spend months performing the tasks while recordings are made.
- Thus monkeys = overtrained and most likely perform tasks different to that of a naïve human subject.
- hard to use this to explain human functioning.
Why shouldn’t we use animals: spenny
- Expensive
- Special environment needed to keep animals in
- If you don’t think of the right q’s when experimenting with animals = waste of everyones time.
Why shouldn’t we use animals: distresses animals
- Ethical reasons - may distress animals.
- unless it has a direct benefit (e.g. the covid vaccine) - ppl argue it’s not right
- distress - influences behaviour /physiology - Affects findings.
Lots of animal research – mice are very stressed/starved to the point that the “Reward” form the task = irresistible
When did animals in research start getting legal protection?
in 1959 when Russel and Burch came along - created the concept of the 3R’s in “The Principles of Humane Experimental Technique”
- Replacement – methods which try avoid/replace using animals in research where possible
- Reduction – methods that reduce the number of animals used per experiment
- Refinment – methods which minimise suffering and improve animal welfare
What did the ideas put forward by Russel and Burch lead to..?
The Animals (scientific procedures) Act, 1986.
- protects animals in any experimental or other scientific procedure which may cause pain, suffering, distress or lasting harm to the animal.
- Protected animals under the Act are any living vertebrate other than man and any living cephalopod
What did the The Animals Act, 1986 changes mean for the animals
- Protection
- No animal can be used without 3 home office licences being in place
- Establishment licence
- Project licence
- Personal licence
How can we choose the species of the animal we use?
- Scientific procedures Act limits the number of species we can work with.*
- the highest primate we can use is the rhesus monkey. Cant use great apes or chimpanzees*
- Can choose animals based on well validated studies in the past. to build on things we already know - often leads to using rats or mice.*
when would you use an animal even if there is. areaonable alternative to them available?
EEG, TMS and fMRI can all be applied to both humans and animals. Why then use animals?
- allow for more precise manipulations to to the nervous system
- Better targeting of the process you want
Why are animal studies better than human studies?
Better resolution in techniques in animals compared to the techniques available to humans
- Yes, both EEG (temporal) and fMRI (spatial) good resolution
- but animal - single cell electrophysiology - can look at the activity of specific neurons in the brain
What is single cell electrophyisology
look at the activity of specific neurons in the brain. Implant electrode into mouse/rats brain and record neurons firing.
- clear spatial and temporal resolution
- pretty clear precision (within microns)
Describe how O’keefe used extra-cellular single unit recordings
- He placed electrodes into target site
- While animal runs around its environment these cells fired when they were in certain regions
- After the animals been killed – you can confirm the placement of those electrodes
This research led to hypothesis that – hippocampus contained the neural basis of a cognitive map.
How can we use single single unit recordings in human studies
Miller et al., 2012
- n with epilepsy had eleectrodes implanted anyways
- researchers just hopped on the back of this, didnt stimulate any area but just listened
- then gave n a series of tasks - remember locations, events occurring in different locations and asked to recall these
- Found certain place cells = active while n recalled such space-related information
How has animal research been used to guide human studies
Well when john o’Keefe found place cells in mice that seemed specific to space that was 1 thing. But then when Miller et al., 2012 used single unit recordings in humans were related to spatial information processing
really drove home the fact that these cells were involved in space. Showed that the
- exploration level the items - stored with the context
- retriving even single items reinstates the context and potentially cue othe r context related memories
What cells have been discovered using animal research?
- Place cell
- HD cell
- Boundary cell
- Grid cell
What happens when GABA binds to the GABA A receptor?
- causes the opening of an associated ion channel that is permeable to the negatively charged ion chloride
- when -CL ions flow into the neuron they hyperpolarise the membrane potential of the neuron
- decreases the likleihood it fires an AP
What happens when GABA binds to the GABA A receptor?
- when activated they frequently cause the opening of potassium channels
- channels allow positively charged potassium ions to flow out of the neurosn
- again make neuron hyperpolarised and less likely to fire an action potential
Six steps to optoginetics?
- Piece together genetic construct: premotor to drive expressio, gene-encoding opsin (light sensitive ion channel)
- Insert construct into virus
- Inject mouse with virus into their brain; opsin is expressed in targeted neurons
- Insert optrode fibre optic cable plus electrode onto mouse head
- Laser light of specific wavelength opens ion channel in neurons.
