06 March 2025: Japanese macaques incarcerated for years to be used in brain experiments in Japan

Two male Japanese macaques (also known as snow monkeys) were used in this invasive brain function research at the Tokyo Metropolitan Institute of Medical Science, Japan (Nakayama et al 2025). This experiment was approved by the institution's animal use committee.

The macaques had been previously used by the researchers in similar experiments, and several years ago they were forced to undergo highly invasive surgery to implant devices in their brains. After being anaesthetised, the skin over their skulls was cut into to reach the bone. Screws were implanted and two plastic 'pipes' were attached to the skull with glue. A portion of the skull was removed so that a recording chamber could be implanted.

In this experiment, the macaques were restrained in a primate chair and their heads were further restrained, presumably using the plastic 'pipes'. Their arms were also strapped to the chair, but their hands were free to move and press buttons. Electrodes were inserted into the brain. The macaques were trained to perform a button-press task that required them to press a small button with either the right or left hand or to press both buttons simultaneously with both hands based on the instructions provided through a computer screen display. The movement of their eyes and signals from the brain were recorded during testing. Correct responses allowed the macaques to receive a drop of apple juice as a reward.

The ultimate fate of the macaques was not mentioned. There is very little information provided about these two individuals, despite having been incarcerated and used in research over several years at the Tokyo Metropolitan Institute of Medical Science.

The lives of these two macaques have been completely controlled, during which they have had to endure the stress of being held in laboratory conditions, major invasive brain surgery, severe restraint and coerced into carrying out tasks. Not only are the findings in these macaques of little use to understanding human brain function responsible for limb movement – the purported reason for doing the experiment – humane and human-relevant research of this type is regularly being done (albeit without subjecting volunteers to the brutal surgery used in the macaques). It is only through elegant and sophisticated studies on human volunteers and patients that progress will be made in understanding brain function and how to manage related illnesses

Nakayama, Yoshihisa; Yokoyama, Osamu; Hoshi, Eiji and Nishimura, Yukio 2025-01-21 Premovement neuronal activity in the primary motor cortex is associated with the initiation of ipsilateral hand movements in monkeys Neuroscience Research Neurosci Res. 2025 Jan 21:S0168-0102(25)00015-X. doi: 10.1016/j.neures.2025.01.005. Online ahead of print.(Neurosci Res. 2025 Jan 21:S0168-0102(25)00015-X. doi: 10.1016/j.neures.2025.01.005. Online ahead of print.):Neurosci Res. 2025 Jan 21:S0168-0102(25)00015-X. doi: 10.1016/j.neures.2025.01.005. Online ahead of print.

Primate chairs:

So-called 'primate chairs', such as those manufactured by Crist Instrument Co, are restraint devices which secure the individual in an unnatural sitting position. Further restraint is often used through a neck plate which goes around the neck to prevent side-to-side or front to back movements of the head. The head may be severely restrained through the use of a post surgically implanted into the skull and held by part of the chair. Depending on the procedures being done, the arms and legs may be secured further by taping them to the chair supports.

11 February 2025: Monkeys subjected to brutal surgery in the Netherlands

Rather than using their intellect and resources compassionately, researchers at the Netherlands Institute for Neuroscience (KNAW) in the Netherlands have prepared a 'how to' publication on abusing rhesus macaques in the name of science (Papale et al 2025. The work, which was publicly funded by the Dutch Ministry of Science and the European Union, was approved by Centrale Commissie Dierproeven of the Netherlands and published in the journal Neuron, produced by @CellPressNews.

The researchers disingenuously claimed that two adult male rhesus macaques (just referred to as monkey F and monkey N) participated in this project, as if the monkeys had a choice and would have allowed themselves to be treated in such a brutal fashion! They were subjected to three head surgeries over a period of many months. The first was to implant posts into the skull to be used later to restrain the individuals' heads. The second surgery, several months later, involved dissecting away skin over the skull in order to implant a base plate for use with a bundle of electrodes. Several months after that, an additional surgery (craniotomy) was done to open up the skull and implant electrodes that entered the brain. In order to do this, part of the cheek bone was cut out for access.

As part of the testing process, the macaques' access to fluids was controlled in order to 'motivate' them to carry out certain tasks. Testing involved restraining them in an unstated device, with their heads firmly fixed, while they 'performed' tasks for fluid rewards. No information was provided on how long the macaques were used in this research nor their ultimate fate.

The research industry continually claims that non-human primates are used in research only when absolutely necessary and only when there are no other alternatives available. This shameful project, which resulted in substantial suffering for the monkeys, demonstrates the meaningless nature of such assurances and a lack of commitment to stop using non-human primates. Funding agencies are largely to blame for this. For the sake of science, if for nothing else, they must support only humane and human-relevant alternatives or improving those that already exist, rather then paying researchers to concoct new ways of abusing non-consenting beings such as non-human primates.

Papale, Paolo; Wang, Feng; Self, Matthew W. and Roelfsema, Pieter R. 2025-01-09 An extensive dataset of spiking activity to reveal the syntax of the ventral stream Neuron S0896-6273(24)00881-X

Craniotomy:

This is a surgical procedure to access the brain. Typically, an area on the head is shaved. An incision is made through the skin and tissues underlying it, down to the surface of the skull, in such a way as to create a flap that can be pulled away to expose the skull. Depending on what type of access to the brain is required, holes may be drilled through the skull into the brain cavity, for example for injections, or a portion of the bone may be cut out in order to implant a bank of electrodes. When done, bone cement may be used to fill in the hole in the skull and the overlying tissues sutured.

20 January 2025: Baby monkeys subjected to chronic stress in Chinese laboratory to study depression

With no compassion or concern for the suffering they were inflicting, Chinese researchers studied the effects on chemicals in the spinal fluid of baby rhesus macaques after subjecting them to chronic stress and substantial suffering, including depriving them of their mothers, in order to induce 'depression' (Li & Feng 2024). This brutal treatment inflicted upon the baby monkeys was authorized by the Animal Care and Use Committee of Kunming Animal Research Institute and had passed the ethical review of animal experiment welfare of Kunming Institute of Zoology, Chinese Academy of Sciences. The results of the experiment were published in the journal Brain and Behavior, produced by @WileyGlobal.

Eight newborn male rhesus monkeys were used in this inhumane experiment. Four were removed from their mothers at birth, and were forced to live alone in an incubator for one month. After that, they were housed, again without their mothers, in pairs in small steel cages for about six months. The other four babies were allowed to remain with their mothers for seven months. All eight monkeys were then housed together for a period of time before being held in single cages.

Over the next several months, the babies were subjected to what the researchers characterised as unpredictable chronic stressors which were designed to cause extreme stress and highly abnormal behaviour. These included further restriction of space; intimidation by unknown methods; keeping lights on for abnormal and prolonged periods; and withholding of all food for an unstated period of time. These stressful conditions were randomly administered.

Throughout the 'study', the babies were repeatedly removed from their cages and anaesthetised to get cerebrospinal fluid using a needle inserted into the lumbar (lower) region of their spinal canal. Removal of cerebrospinal fluid can cause severe headaches, backaches, nausea and vomiting, dizziness and other problems in humans. It is reasonable to assume that all non-human primates can also be subject to these complications. The ultimate fate of the babies was not stated nor was any information provided on the behaviour of the babies or the mothers whose babies were removed from them. The researchers did point out that their previous research using similar methodology caused significant depressive behavior in macaques including reduced movement; stereotypical behaviours; huddling or curling up in their cages.

Li, Siyu and Feng, Xiaoli 2024-08-01 Dynamic quantitative monitoring of cerebrospinal fluid monoamine neurotransmitter markers during the modeling process of chronic stress-induced depression in monkeys (Macaca mulatta) Brain and Behavior 14(8):e3636

15 January 2025: CITES Secretariat recommends suspension in macaque trade from Cambodia

Action for Primates has welcomed a recommendation from the CITES Secretariat to suspend the trade in long-tailed macaques from Cambodia. This recommendation to the CITES Standing Committee will be voted on at a forthcoming meeting in Geneva on 3rd-8th February 2025. If accepted, the Standing Committee will recommend that all member countries stop importing long-tailed macaques from Cambodia.

This recommendation follows a CITES Review looking into the breeding and trade in long-tailed macaques, which has questioned the validity of the source codes used on CITES export permits, in particular claims of captive-breeding. A five-year US Fish and Wildlife Service (USFWS) investigation into monkey trafficking revealed that wild long-tailed macaques in Cambodia were being falsely labelled as captive bred at Cambodian facilities (including Vanny Bio Research (Cambodia) Corporation Ltd). Unable to breed enough long-tailed macaques to supply the demand from the USA import and user companies, it was claimed that Vanny Bio Research started to illegally source wild-caught monkeys and export them labelled as captive-bred. The USFWS subsequently denied permits for the import of macaques from Cambodia, but other countries, including Canada, which has imported thousands of macaques in recent years, have continued to do so. The exploitation of this species is driven by the global trade in long-tailed macaques for the research and toxicity (poisoning) testing industry.

Sarah Kite, co-founder, Action for Primates, stated: We welcome this recommendation by the CITES Secretariat. Action for Primates, with other wildlife and conservation groups, has for many years been pushing for greater conservation protection for the long-tailed macaque in Cambodia and neighbouring countries, raising concerns about the credibility of captive-breeding claims, the conservation status of the species and the impacts of increasing international trade on that status.

Investigation of the macaque trade in Cambodia was recently the subject of a Bloomberg documentary: "The Dirty Business of Monkey Laundering | Bloomberg Investigates".

Convention on International Trade in Endangered Species of Wild Fauna and Flora