In a new series called “What if nonhuman primate research goes away?”, The Transmitter has published an article by journalist Alissa de Chassey that addresses open questions in neuroscience which require research using monkeys, based on interviews with 17 neuroscientists who have worked with non-human primates (NHPs).

Despite the valuable insights provided by other animals such as mice, the article argued that the similarities between the monkey brain and the human brain make NHPs a particularly valuable model for answering specific questions in five neuroscience areas: vision, cognition, motor control, social behaviour and emotion, and development and ageing. For example, monkeys have forward-facing, binocular vision, while mice have panoramic vision, and monkeys have a fovea, a region of the retina involved in high-acuity vision. 

Monkeys also have complex cognitive skills and a large prefrontal cortex, making them essential to understand, for instance, which neuronal circuits are important for reasoning. Their advanced motor control can provide insights into unsolved questions such as why primates, including humans, recover motor skills so poorly after stroke compared with rodents and help develop better treatments for Parkinson’s disease. Monkeys form long-term social relationships and can experience affective states that mirror human conditions such as depression, anxiety, obsessive-compulsive disorder and autism. Finally, the NHP lifetime is long enough to study development and ageing, resembling human developmental stages, while still short enough to support research.

This series follows recent developments in the US to prioritise research with New Approach Methodologies, such as organoids and computer models, as a replacement for animal research. Yet, these models lack perception, bodily input and cognition.

“It is an exciting time, that some of these novel approaches are coming to fruition. But they’re really not quite ready to replace whole animals,” said Jay Rappaport, director of the Tulane National Biomedical Research Center.