Animal Research
'Animal research' involves the use of non-human animals in scientific experiments to understand biological systems, diseases, and the effects of treatments.
🔬 What is Animal Research?
Animal research is conducted to study:
Biological systems (e.g., neurobiology, physiology)
Disease models (e.g., cancer, Alzheimer’s, infections)
Drug development and safety testing
Behavioral and psychological processes
🐁 Why Are Animals Used?
Reasons for using animals in research:
Biological similarity to humans
Short lifespans and rapid reproduction (ideal for generational studies)
Some studies are unethical or impossible in humans
Controlled environments reduce confounding variables
📉 Common Species Used
Rodents (mice, rats): genetics, cancer, neuroscience
Primates: infectious diseases, brain studies
Zebrafish: developmental biology, toxicology
Fruit flies and nematodes: aging, genetics
Pigs, dogs, cats (less common): organ studies, surgical techniques
⚖️ Ethical Considerations
Animal research raises important ethical issues:
Animal suffering and welfare
Scientific necessity and justification
Use of alternatives (in vitro models, simulations)
Oversight to ensure humane treatment
The '3Rs principle' guides ethical animal research:
'Replacement': use non-animal methods when possible
'Reduction': use the minimum number of animals necessary
'Refinement': minimize suffering and improve conditions
📚 Regulations and Oversight
'EU': Directive 2010/63/EU
'USA': Animal Welfare Act; IACUC review
'Spain': Real Decreto 53/2013
🧠 Example Study: Brain Changes in Captivity
A recent study on the common shrew (Sorex araneus) showed that:
Seasonal brain size changes remain intact under semi-natural captivity
However, captivity increased activity and reduced learning motivation
Results suggest chronic stress in captivity, which can bias experimental outcomes
Conclusion: Even well-controlled captive environments may affect research results and must be accounted for in experimental design.