Anatomical and functional investigation of the marmoset default mode network

The default mode network (DMN) in humans is characterized by strong connections among the medial prefrontal cortex, posterior parietal cortex, and posterior cingulate cortex. In common marmosets, however, the dorsolateral prefrontal cortex shows robust functional and anatomical connections with the posterior DMN regions, while the medial prefrontal cortex has weak connections. This pattern differs markedly from the human DMN, suggesting that the medial prefrontal cortex may support brain functions that are more developed in humans than in other primates.

Study at a glance

Abstract

The default mode network (DMN) is associated with a wide range of brain functions. In humans, the DMN is marked by strong functional connectivity among three core regions: medial prefrontal cortex (mPFC), posterior parietal cortex (PPC), and the medial parietal and posterior cingulate cortex (PCC). Neuroimaging studies have shown that the DMN also exists in non-human primates, suggesting that it may be a conserved feature of the primate brain. Here, we found that, in common marmosets, the dorsolateral prefrontal cortex (dlPFC; peak at A8aD) has robust fMRI functional connectivity and reciprocal anatomical connections with the posterior DMN core regions (PPC and PCC), while the mPFC has weak connections with the posterior DMN core regions. This strong dlPFC but weak mPFC connectivity in marmoset differs markedly from the stereotypical DMN in humans. The mPFC may be involved in brain functions that are further developed in humans than in other primates.