Hypotheses on Mechanisms Linking Cardiovascular and Psychiatric/Neurological Disorders

This special issue of Cardiovascular Psychiatry and Neurology marks its first year since we launched the open access journal dedicated to publishing original preclinical/basic and research on biological mechanisms of and treatments for co-occurring cardiovascular disorders and disorders of the central nervous system (CNS). As suggested earlier (by the paper entitled " The heart-brain connection begets cardiovascular psychiatry and neurology " by Hari Manev), at least three scenarios could be at play in these disorders: (1) the primary pathological mechanism in the cardiovascular system triggers a nervous system dysfunction, (2) the primary pathological mechanism in the nervous system triggers a cardiovascular pathology by disrupting the physiological links between the two systems, and (3) the primary pathology is in a biological mechanism that is normally operative in both the nervous and the cardiovascular systems, thus causing the cooccurrence of pathologies, that is, the cooccurring pathologies share a pathobiological mechanism but do not necessarily cause each other. The ongoing research explores the validity of these conceptual scenarios. Whereas the evidence for the association of cardiovascu-lar and CNS disorders derives primarily from epidemiological studies, direct evidence and experimental data are just beginning to emerge to support this notion. Difficulties in directly demonstrating and explaining the cooccurrence of cardiovascular and CNS disorders lie in part in the limitations of their respective animal models (in particular animal models of psychiatric disorders) and in part in conceptual uncertainties regarding the mechanisms linking heart-brain pathologies that hamper respective clinical research. Historically , bold hypotheses along with serendipitous observations have been instrumental in breakthrough discoveries. This collection of hypotheses on mechanisms linking cardiovascular and psychiatric/neurological disorders has been assembled with the goal of stimulating discussions in this field of bioscience and medicine. The postulated mechanisms range from molecular targets and pathways (the papers by Sébastien S. Hébert entitled " Putative role of microRNA regulated pathways in comorbid neurologi-cal and cardiovascular disorders " , by David P. Gavin and Rajiv P. Sharma entitled " Chromatin from peripheral blood mononuclear cells as biomarkers for epigenetic abnormalities in schizophrenia " , by Neil R. Smalheiser entitled " Do neural cells communicate with endothelial cells via secretory exosomes and microvesicles? " by Stephen D. Skaper and Pietro Giusti entitled " P2X7 receptors as a transducer in the cooccurrence of neurological/psychiatric and cardiovascular disorders: A hypothesis " , by Charles D Nichols entitled " Serotonin 5-HT2A receptor function as a contributing factor to …