Influence of arginine vasopressin on the ultradian dynamics of Hypothalamic-Pituitary-Adrenal axis.

Numerous studies on humans and animals have indicated that the corticotrophin-releasing hormone (CRH) and arginine vasopressin (AVP) stimulate both individually and synergistically secretion of adrenocorticotropic hormone (ACTH) by corticotropic cells in anterior pituitary. With aim to characterize and better comprehend the mechanisms underlying the effects of AVP on Hypothalamic-Pituitary-Adrenal (HPA) axis ultradian dynamics, AVP is here incorporated into our previously proposed stoichiometric model of HPA axis in humans. This extended nonlinear network reaction model took into account AVP by: reaction steps associated with two separate inflows of AVP into pituitary portal system, that is synthesized and released from hypothalamic parvocellular and magnocellular neuronal populations, as well as summarized reaction steps related to its individual and synergistic action with CRH on corticotropic cells.

Profiling differences in chemical composition of brain structures using Raman spectroscopy.

Raman spectroscopy enables non-invasive investigation of chemical composition of biological tissues. Due to similar chemical composition, the analysis of Raman spectra of brain structures and assignment of their spectral features to chemical constituents presents a particular challenge. In this study we demonstrate that standard and independent component analysis of Raman spectra is capable of assessment of differences in chemical composition between functionally related gray and white matter structures.