As a model system, ferrets offer many advantages for neuroscience research:
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Development: Ferrets undergo considerable postnatal development. At birth, cortical layer 4 neurons are migrating, and cortical layer 2/3 neurons are still dividing. Therefore, one can perform experiments that manipulate the development of cortex in postnatal animals. Ferrets open their eyes at about 28-34 days of age, at a time when the eye is well focused. They also exhibit a large population of outer subventricular zone neurons (OSVZ), which are found in higher mammals. Further, the ferret exhibits a longer period of adolescence than rats or mice that can be studied over days or weeks.
Gyri and sulci: The ferret brain has folds, allowing the study of:
the development and function of gyri and sulci
how a gyrencephalic brain reacts to explosive blast
Greater white to gray matter ratio than rodents
Auditory processing: Ferrets exhibit a frequency range that is well matched to human perception at both low and high frequencies (as opposed to rats and mice, which primarily hear high frequencies)
Vomiting reflex: Unlike rats and mice, ferrets do vomit.
Technical advantages:
Ferrets are larger than mice and rats, permitting some experiments that require heartier physiology, heavier equipment, or fine surgical manipulations
Ferrets are still small enough to fit into preclinical MRIs unlike higher order animals.
Ferrets can be taught to perform behavioral experiments
Hippocampal location: in mice/rats the hippocampus sits just under the cortex, but in the ferret it is deep in the brain, similar to the human. This is an important difference when studying the behavioral outcomes after a contusion brain injury - in mice you may also damage the hippocampus due to its location, whereas this is less of an issue in humans and ferrets.