En vivo neuroimaging of the choroid plexus to characterize neuroinflammation in restrictive eating disorders

Despite the important role the choroid plexus (CP) plays in brain homeostasis, it is largely unexplored in psychiatry. The CP consists of a network of capillaries enclosed by a single layer of epithelial cells joined together by tight junctions to form the blood-CSF barrier. The blood-CSF barrier is an active barrier, secreting CSF and transferring metabolites from CSF to blood bidirectionally, and thus, playing a crucial role in communicating inflammatory reactions from the periphery to the central nervous system. Integrity of the CP is crucial for maintaining CSF ion homeostasis and blood-CSF barrier permeability. Enlargement of CP may reflect greater neuroinflammation, as abnormal function of the CP requires greater passage of peripheral inflammation markers to dampen neuroinflammation. The current study explores the role of the choroid plexus in restrictive eating disorders, severe psychiatric disorders in which disruptions in appetite and motivation are hypothesized to be maintained by neuroinflammation. Adolescents and young adults with anorexia nervosa (N= 59) and age-matched healthy controls (N=39) completed 3T MRI scans which were parcellated with Freesurfer, as well as hand-drawn masking of the lateral choroid plexus by a neuroanatomist, to capture CP enlargement in cases and controls. To confirm that enlargement was driven truly by the CP, we ran a series of linear models accounting to total lateral ventricles, total gray matter, and lateral ventricles + total gray matter. We also compared freesurfer CP volumes to hand-draw models and discuss challenges of CP imaging. In all models, the left CP was significantly lager in eating disorders, compared to controls (all p< 0.001). Correlations with targeted-proteomics of peripheral inflammation markers will be incorporated in future analyses. In addition, we will discuss and incorporate on-going collection of CSF in cases, to discuss central and peripheral inflammation relationships with CP enlargement