more intriguing, experiments suggest that atrial peptide caninfluence motivation and behavior (Telegdy, 1994).Several years following the discovery of atrial peptide, a related peptide hormone with similarbiological functions was identified. This was called brain natriuretic peptide (BNP) because itwas first identified in porcine brain. It soon became clear, however, that the main source of thispeptide was the cardiac ventricle rather than the brain, and brain natriuretic peptide is nowsometimes called B-type natriuretic peptide (Mukoyama et al., 1991).Armour and colleagues also found that the heart contains a cell type known as intrinsiccardiac adrenergic cells. These cells are so classified because they synthesize and releasecatecholamines (norepinephrine, epinephrine, and dopamine), neurotransmitters once thought tobe produced only by neurons in the brain and ganglia outside the heart (Huang et al., 1996).More recently still, it was discovered that the heart also manufactures and secretes oxytocin,commonly referred to as the love or social bonding hormone. Beyond its well-knownfunctions in childbirth and lactation, recent evidence indicates that this hormone is also involvedin cognition, tolerance, trust, complex sexual and maternal behaviors, as well as in the learningof social cues and the establishment of enduring pair bonds. Remarkably, concentrations ofoxytocin produced in the heart are in the same range as those produced in the brain (Gutkowskaet al., 2000).In a preliminary study (10 participants), we examined changes in the blood concentrations ofoxytocin and atrial peptide before and after 10 minutes of maintaining the psychophysiologicalcoherence mode, which was generated by a loving emotional focus. While an increase inoxytocin was observed for the whole sample, it was not statistically significant, although it likelywould have been with a larger sample. On the other hand, despite the small number of cases, thedecrease in atrial peptide was significant. As atrial peptide release is an index of the stretch andcontractile force of the atrial wall of the heart, these data suggest that cardiovascular efficiencyincreases during the psychophysiological coherence mode. The results for the male and femalesubgroups in this study are shown in Figure 6.INTEGRAL REVIEWDecember 2009Vol. 5, No. 2Heart Hormones Before and After CoherenceFigure 6. Oxytocin and atrial peptide changes during heart rhythm coherence. Graphs showchanges in blood levels of oxytocin and atrial peptide for male and female subgroups from aresting baseline mode to after maintaining the coherence mode for 10 minutes.In addition to changes in the amount of a heart hormone released into the blood affectingcellular and psychological systems, there is also evidence that the temporal pattern of thehormonal release has substantial effects independent of the amount of the hormone released. Ithas been known for some time that neurotransmitters, hormones, and intracellular secondmessengers are released in a pulsatile fashion. Pulsatile patterns of secretion are observed fornearly all of the major hormones, including ACTH, GH, LH, FSH, TSH, prolactin, beta-endorphin, melatonin, vasopressin, progesterone, testosterone, insulin, glucagon, renin,aldosterone, and cortisol, among many others.Recent studies by German endocrinology researchers Georg Brabant, Klaus Prank, andChristoph Schofl have shown that, in much the same way that the nervous system encodesinformation in the time interval between action potentials, biologically relevant information isalso encoded in the temporal pattern of hormonal release, across time scales ranging