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Action for Primates

Examples of Recent Experiments Using Non-human Primates

Below are samples of recent publications from laboratories in which non-human primates were used in experiments (see previous entries in our archives). Our intention is to provide details of the types of research to which non-human primates are being subjected. Bear in mind that what we list here is only a tiny example of the dozens of experiments published each week.

Although we emphasise welfare issues with respect to how the research impacted on the animals, please bear in mind that the non-human primates used were all essentially wild animals, even if bred in captivity. Because of this, the suffering and stress of being in captivity was inherent in every case.

• 2021-01-04: "Chronic unpredictable mild stress produces depressive-like behavior, hypercortisolemia, and metabolic dysfunction in adolescent cynomolgus monkeys" Teng, Teng; Shively, Carol A.; Li, Xuemei; Jiang, Xiaofeng; Neigh, Gretchen N.; Yin, Bangmin; Zhang, Yuqing; Fan, Li; Xiang, Yajie; Wang, Mingyang; Liu, Xueer; Qin, Mengchang; Zhou, Xinyu and Xie, Peng. Translational Psychiatry 11(1):9.

Young monkeys were deliberately subjected to extremely cruel and barbaric treatment in an attempt to simulate human teenage depression. Although this recently published research was done at Chongqing Medical University in China and supported mostly with Chinese funding, there are two US authors, one from Wake Forest School of Medicine (who was supported by a National Institutes of Health grant) and another from Virginia Commonwealth University. The work was approved by the Ethics Committee of Chongqing Medical University, but there is no mention of any oversight or decisions by ethics committees at either of the US facilities. The latter is disturbing in and of itself.

In the research, ten male adolescent long-tailed macaques, some less than two years old, were used. They were housed singly in cages. The 'experimental' group (as opposed to those serving as 'controls') were subjected to chronic unpredictable mild stress for seven days, and then observed for four days. This cycle was repeated four more times. The stressors the monkeys were subjected to, in some cases lasting 24 hours, included:






Noise: A buzzer with a 100 decibel shrill chirp was placed in the monkeys' room for 12 hours from 8:00 PM to 8:00 AM the following day. According to the US Centers for Disease Control and Prevention (CDC) noise above just 70 decibels over a prolonged period of time may start to damage your hearing.
Water deprivation: The monkeys were deprived of water for 12 hours from 8:00 PM to 8:00 AM the following day.
Food deprivation: The monkeys were deprived of food for 24 hours from 8:00 AM to 8:00 AM the following day.
Space restriction: The cage space of the monkeys was restricted by a push-pull device for four hours from 8:00 AM to 12:00 PM.
Cold stress: The monkeys were sprayed with 10°C water for ten minutes. Although long-tailed macaques are known for their affinity for water, the natural conditions do not involve such cold water nor for such an extended period. Further, under natural conditions, the macaques emerge into a warm and usually sunny environment so that they can dry off quickly.
Exposure to stroboscope: Flashing stroboscopes were placed facing the monkey cages for 12 hours from 8:00 PM to 8:00 AM the following day. Flicker causes disturbance and can cause physiological effects such as headaches, at least in people.
Inescapable foot shocks: The monkeys were exposed to foot shocks by an electric shock stick from which they could not escape. The shock was 6 volts lasting 10-15 seconds with intervals of ten seconds. The monkeys received 3-4 rounds of this.

Two different stressors were used each day. The macaques' behaviour was observed and recorded, their weight was recorded and certain standard 'tests' were done to see the difference between 'controls' and stressed individuals. The researchers were looking for both depressive-like behaviours and anxiety-like behaviours, such as a huddle posture, self-clasping with head at or below the shoulders.

This is a shocking and damning indictment of the appalling way in which non-human primates are abused in the name of science. The mental anguish and torment these monkeys must have suffered is unimaginable. As a gesture to ethics, the researchers provided the monkeys with an eight-hour window each day when they allowed the animals social contact with each other, toys (already scientifically proven to be of only transient value) and fruit and vegetables (apart from those of food deprivation) ...to meet experimental requirements set by the institutional animal care and use committee..., which they admit may have influenced the outcome of the study.

The researchers were trying to establish a non-human primate 'model' for human adolescent depression, and yet their paper states that ...youth with depression experience more serious impairments in global functioning, an increased risk of tobacco smoking and other substance abuse². Moreover, suicide is the third leading cause of death in adolescents; and among depressed youth, 29% experience suicidal thoughts and 11% attempt suicide⁴. All these depressive behaviours, critical in understanding and helping troubled human adolescents, are not reproducible in non-human primates, rendering the authors' abjectly inhumane 'model' of no relevance.

The researchers stated that they were able to ...induce depressive-like and anxiety-like behaviors... in macaques. By using such terms, however, the authors clearly acknowledge that their 'model' is only superficially similar to the situation seen in adolescent human teenagers. Despite this, the researchers conclude that subjecting macaques to chronic stress provides ...a promising model to study the mechanisms underlying adolescent depression. No amount of artificial and cruel stressors inflicted on macaques can compare with the complex emotional, genetic and environmental stressors that cause mental illness and depression in human teenagers.

The Wake Forest School of Medicine claims that the goal of their Animal Welfare Program ...is to ensure that animals at Wake Forest are always treated ethically and humanely. Virginia Commonwealth University states that their Animal research program places ...the ethical treatment of animals as a primary responsibility and the founding principal [sic] of our animal care and use program and that they employ the ...ethical mandates, known as 'The Three Rs' of animal research (Reduction, Replacement and Refinement). Did these institutions approve the involvement of their representatives in research that was not only extremely cruel, but also of no scientific merit? Would they consider the research they endorsed, albeit indirectly, to be 'humane'?