Pulvinar subdivisions and connectivity patterns across primate species: a comparative perspective

With the advances in our ability to perturb brain activity in recent years, new stimulation techniques have become essential tools in human neuroscience. Non-invasive stimulation methods, such as transcranial magnetic stimulation (TMS), as well as deep brain stimulation (DBS) delivered invasively to access deep brain structures, have been applied in both basic and clinical research and in the treatment of neurological conditions including Parkinson's disease, essential tremor and epilepsy. In the context of epilepsy, neuromodulatory interventions have demonstrated encouraging results in reducing seizure frequency, bringing attention to the thalamic pulvinar nucleus as a potential target for stimulation in drug-resistant cases. To advance these and future therapies, it is necessary to have a more detailed understanding of the subdivisions and connectivity patterns of these nuclei. Although some human studies have employed diffusion imaging and fMRI, much of the current knowledge of pulvinar connectivity still comes from non-human primate (NHP) studies. The aim of this study is to review the cortico-pulvinar connectivity patterns of distinct pulvinar subregions across NHP species, alongside available human studies, to help optimize future basic and clinical research.