Mouse models of neurodegenerative diseases have proven inadequate in translation into clinical research. There are several reasons, one of them is that in these animals the diseases progress at an extreme speed and the other is that mice and primates have quite different nervous systems.
For example, in some cases, higher primates have direct connections between upper and lower motor neurons, whereas mice always have interneurons between upper and lower motor neurons.
Source: Xocolatl via Wikipedia
The common marmoset, Callithrix jacchus, is increasingly being used as the preferred nonhuman primate model in biomedical research. Marmosets share several physiological and biological similarities with humans, and their use in research programs advances knowledge of several fields.
Mice diseases models are highly unrealistic, when transposed to humans it would mean that degeneration would appear at 20 years old! Due to the relatively shorter life span of 15 to 16 years and the smaller body size, studies conducted in marmosets may be more realistic. Since neurodegeneration is prevalent in aging humans, there has been much interest in the neurodegeneration of aging marmosets.
Their unique characteristics, such as small size, high fecundity, and rapid growth, offer additional advances in laboratory settings. This article reviews the developments in experimental disease models using marmosets based on authors' experience at the Central Institute for Experimental Animals in Japan.
The development of genetically modified marmoset models using advanced genome editing technology attracts researchers, particularly in neuroscience-related fields. In parallel, various marmoset models of human diseases induced by surgery or drug administration have contributed to preclinical and translational studies.
Among these are models:
- for Parkinson's disease, induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine;
- spinal cord injury models;
- a model for type 1 diabetes, induced by the combination of partial pancreatectomy and streptozotocin administration;
- a hepatic fibrosis model induced by thioacetamides.
The development of these models has been supported by refinements in veterinary care, such as the careful design of anesthetic protocols and better understanding of pathogenic microorganisms. In the second part of this review, the authors present a compilation of practices currently in use at at the Central Institute for Experimental Animals that provide optimal animal care and enable safe experimentation.
Indeed, most researchers will be reluctant to use marmosets. Diseases of mice models appear within a month, so the cost is low. No university lab would spend years before the results are available. If only for one thing, it would considerably slow down the pace of publications that condition the careers of scientists.