Increased Resting Perfusion of the Hippocampus in High Positive Schizotypy: A Pseudo-Continuous Arterial Spin Labeling Study

TY - JOUR

T1 - Increased Resting Perfusion of the Hippocampus in High Positive Schizotypy: A Pseudo-Continuous Arterial Spin Labeling Study

AU - Modinos, Gemma

AU - Egerton, Alice

AU - McMullen, Katrina

AU - McLaughlin, Anna

AU - Kumari, Veena

AU - Barker, Gareth John

AU - Williams, Steven Charles Rees

AU - Zelaya, Fernando Osmin

PY - 2018

Y1 - 2018

N2 - Arterial spin labeling (ASL) provides absolute quantification of resting tissue cerebral blood flow (CBF) as an entirely non-invasive approach with good reproducibility. As a result of neuro-vascular coupling, ASL provides a useful marker of resting neuronal activity. Recent ASL studies in individuals at clinical high risk of psychosis (CHR) have reported increased resting hippocampal perfusion compared with healthy controls. Schizotypy refers to the presence of subclinical psychotic-like experiences in healthy individuals and represents a robust framework to study neurobiological mechanisms involved in the extended psychosis phenotype while avoiding potentially confounding effects of antipsychotic medications or disease comorbidity. Here we applied pseudo-continuous ASL to examine differences in resting CBF in twenty-one subjects with high positive schizotypy (HS) relative to twenty-two subjects with low positive schizotypy (LS), as determined by the Oxford and Liverpool Inventory of Feelings and Experiences. Based on preclinical evidence that hippocampal hyperactivity leads to increased activity in mesostriatal dopamine projections, CBF in hippocampus, midbrain and striatum was assessed. Participants with HS showed higher CBF of the right hippocampus compared to those with LS (p = .031 family-wise error corrected). No differences were detected in the striatum or midbrain. The association between increased hippocampal CBF and HS supports the notion that hippocampal hyperactivity might be a central characteristic of the extended psychosis phenotype, while hyperactivity in subcortical dopamine pathways may only emerge at a higher intensity of psychotic experiences.

AB - Arterial spin labeling (ASL) provides absolute quantification of resting tissue cerebral blood flow (CBF) as an entirely non-invasive approach with good reproducibility. As a result of neuro-vascular coupling, ASL provides a useful marker of resting neuronal activity. Recent ASL studies in individuals at clinical high risk of psychosis (CHR) have reported increased resting hippocampal perfusion compared with healthy controls. Schizotypy refers to the presence of subclinical psychotic-like experiences in healthy individuals and represents a robust framework to study neurobiological mechanisms involved in the extended psychosis phenotype while avoiding potentially confounding effects of antipsychotic medications or disease comorbidity. Here we applied pseudo-continuous ASL to examine differences in resting CBF in twenty-one subjects with high positive schizotypy (HS) relative to twenty-two subjects with low positive schizotypy (LS), as determined by the Oxford and Liverpool Inventory of Feelings and Experiences. Based on preclinical evidence that hippocampal hyperactivity leads to increased activity in mesostriatal dopamine projections, CBF in hippocampus, midbrain and striatum was assessed. Participants with HS showed higher CBF of the right hippocampus compared to those with LS (p = .031 family-wise error corrected). No differences were detected in the striatum or midbrain. The association between increased hippocampal CBF and HS supports the notion that hippocampal hyperactivity might be a central characteristic of the extended psychosis phenotype, while hyperactivity in subcortical dopamine pathways may only emerge at a higher intensity of psychotic experiences.

M3 - Article

SN - 1065-9471

JO - Human Brain Mapping

JF - Human Brain Mapping

ER -