Rats (and mice) are often the animals of choice to try and model human conditions, treatment and body functions - even though we know that using animals to try and model people fails over 90% of the time.
Mice and rats are commonly used due to their small size, low maintenance (i.e., they are easy to house and care for), short life cycle, and ability to breed quickly (allowing large numbers to be generated for studies).
They also share many of our genes.1 However, that's not surprising. Even cats share many of our genes.2
Rats are used is some of the most gruesome experiments that involve things like force-feeding, poisoning, oxygen deprivation and invasive surgery.
Rats in NZ have been used for:
- Drug research, including safety and efficiency testing.
- Teaching purposes in schools, mainly dissections.
- Investigating ways of killing wild rats. (i.e., research into effective poisons and traps).
- Medical research, including research into the development of severe diseases (i.e., stroke, diabetes, cancer), modelling neurological disorders (i.e., Schizophrenia, Autism), modelling mood disorders (i.e., example, anxiety, and depression) and research into tinnitus.
- Drug addiction research including research into the development and suppression of addictions and the impacts of drug use.
- Basic biological research, including research into digestion, aging, nerve damage, obesity and how the brain functions.
Places that use rats for science in NZ include crown research institutes, private companies and universities. In fact, most universities have their own breeding colonies. Otago University states on its website that they have a dedicated rat testing room in the Behavioural Phenotyping Unit.3
Rats used for science in NZ are sourced from breeding units, public or commercial sources, the wild (captured) and they are imported from overseas.
Discover real-life examples of how rats have been used in NZ below!
Studying how ageing affects brain chemistry
Rats were kept in germ-free, individual cages before being killed. Their brains were used for tests.
Studying cell death in breast tissue
Mother rats had some of their newborns taken away, and several of her teats were sealed off after two weeks. They were killed after different waiting times to analyse the dying tissue.
Testing blood pressure drugs against seizures
Rats were implanted with devices to measure heart and brain activity through induced seizures without being anaesthetised. They were killed two days later, and their hearts were taken.
Testing new drug formulations
Rats and rabbits were injected with a new anaesthetic, pinching their paw repeatedly to measure reflexes. Rats were giving the medication until they died.
Testing effects of meth on brain protein
Rats were taught to inject themselves with meth or a saline solution when they pressed a lever. After 20 days, there were two weeks of abstinence. In the end, all were killed to dissect their brains.
Testing medications for drug addiction
Rats were taught to inject themselves with cocaine when they pressed a lever. Through many cycles of establishment and withdrawal, medications were tested for their effect on drug-seeking behaviour. Other rats were tested for their activity level on cocaine with or without medication. Some were put into water-filled cylinders to examine if medication influences how long they swim.
Teaching animal researchers
A range of animals is used to teach researchers handling and experimental methods.
Testing a new pain medication
Rats were operated on to cause pain build-up in their hind leg. After 10 days, they were injected with different variations of a drug or just a control solution. The effect was tested by poking their hurting leg and having them balance.
Testing a surgical treatment for hypertension with diabetes
Transgenic rats were injected to develop diabetes. Their kidney nerves were surgically destroyed. They were restrained for measurements and sampling regularly. In the end, they were all killed.
Studying the effect of prolactin on the brain
Virgin rats and rats who recently gave birth had a cannula (tube) placed in their brain and were injected with medication. They were injected with prolactin after two days and killed an hour later to dissect their brains.
Trying to study depressants and antidepressants
Rats were kept isolated or in groups for nine weeks. They were injected with different drugs and put through behavioural tests (the notorious Forced Swim Test, among others). In the end, all were killed.
Studying how anaesthetics affect intestine movement
Guinea pigs and rats were anaesthetised, then dissected, and then killed, in that order.
Studying hormone sensitivity of the brain
Female rats were mated, gave birth and cared for their babies for three weeks. They had prolactin injected below the skull. They were killed, and their brains were removed.
Harvesting rabbit and rat hearts for lab tests
NZ White rabbits and rats were killed to use their hearts in lab tests.
Testing digestion of a pig food
Rats were fed a pig food and killed to examine their intestines.
Testing how heart calcium metabolism is different in species
Guinea pigs and rats were decapitated, and their hearts were quickly removed to study them.
