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Mental Health in Lifestyle Medicine
Published in Gia Merlo, Kathy Berra, Lifestyle Nursing, 2023
Lack of sleep is associated with higher-than-normal levels of pro-inflammatory cytokines, which are small proteins necessary for signaling between cells. In people with poor sleep, increased levels of Interleukin (IL)-6, IL-1β, and Tumor Necrosis Factor (TNF)-α have been noted. These specific cytokines have been implicated in the development of depression and other neuropsychiatric disorders (Felger & Lotrich, 2013). These inflammatory cytokines can enter the brain by several different pathways, such as active transport across the blood–brain barrier, across areas such as the circumventricular organs where the blood–brain barrier is incomplete. Cytokines can also travel to the brain via afferent nerve fibers or by attaching to peripheral monocytes that travel to brain cells and glia. Once there, these cytokines affect mechanisms in the hypothalamus, basal forebrain, and brainstem receptors that can trigger what is known as “sickness behavior.” Sickness behavior is a cluster of symptoms including anhedonia, changes in sleep, decreased social interactions, loss of appetite, and low energy, and is thought to be an evolutionary protective response that allows a person who is ill to conserve energy needed for recovery (Felger & Lotrich, 2013).
Chronic Fatigue Syndrome: Limbic Encephalopathy in a Dysregulated Neuroimmune Network
Published in Jay A. Goldstein, Chronic Fatigue Syndromes, 2020
It has been difficult to demonstrate a progesterone abnormality consistently in PMS, but the pulsatile nature of luteinizing hormone (LH) secretion may be dysregulated. The GnRH control over LH secretion is modulated in part by endogenous opioids. IL-1 may exert many of its limbic effects through endogenous opioids,72 since some of its hypothalamic actions can be blocked by naloxone. If CFS is, in part, a disorder of cytokine dysregulation, IL-1 could be secreted by the hippocampus and affect the hypothalamus, or it could gain slow access from the periphery via the circumventricular organs: area postrema, organum vasculosum, choroid plexus (which also manufactures IL-1), pineal gland (perhaps not involved in PMS since melatonin biosynthesis is not abnormal in PMS), and median eminence. A bidirectional transport of IL-1 alpha across the blood-brain-barrier (BBB) has been demonstrated,73 although this finding has not been confirmed by others. The hypothalamus had the highest entry rate. Activated T-lymphocytes may also cross the BBB and release IL-1 (and presumably other cytokines) into particular sites. The circumventricular organs may also function as neuronal transducers of circulating peripheral neuropeptides and cytokines, manufacturing them without allowing their ingress.74
Neural Control of Adenohypophysis
Published in Paul V. Malven, Mammalian Neuroendocrinology, 2019
The median eminence is just one of several unique structures in the brain known as circumventricular organs (CVO). These organs, which are also called neurohemal structures, share a common vascular and ependymal organization, which is different from the rest of the brain. As the name denotes, these organs are all located adjacent to some part of a cerebral ventricle. The capillaries in circumventricular organs have a characteristic fenestrated endothelium that probably accounts for the blood-brain barrier being less restrictive in these organs than in most brain tissue. Circumventricular organs are also unique in that their ependymal cells are non-ciliated, whereas ependymal cells in most other regions are ciliated. The diagram in Figure 4-4 shows the location of four different circumventricular organs including the median eminence. The organum vasculosum of the lamina terminalis (OVLT) is located around the rostral projection of the third ventricle above the optic chiasma. The subfornical organ is located on the midline beneath the descending fornix and in contact with the choroid plexus of the third ventricle. The subcommissural organ lines the roof of the third ventricle beneath the posterior commissure and habenula. The three circumventricular organs not illustrated in Figure 4-4 are pars nervosa, pineal gland, and area postrema. The first two of these are covered in detail in Chapters 3 and 10, respectively. The area postrema is located in the roof of the fourth ventricle caudal to the cerebellum.
Salt-induced phosphoproteomic changes in the subfornical organ in rats with chronic kidney disease
Published in Renal Failure, 2023
Xin Wang, Huizhen Wang, Jiawen Li, Lanying Li, Yifan Wang, Aiqing Li
As a circumventricular organ, subfornical organ (SFO) locates at the caudal of the foramen of Monroe at the confluence of lateral ventricles to the third ventricle. It has a highly vascularized core lacking a blood-brain barrier and possesses a dense population of ion channels and hormone receptors. These properties allow SFO to directly detect the factors in cerebrospinal fluid (CSF) and blood, such as Na+, Ang II, and aldosterone [6–8]. For example, Nax channel expressed explicitly in the glial cells of SFO and organum vasculosum lamina terminalis (OVLT) as the most characterized brain [Na+] sensor [9,10]. SFO detects changes in [Na+] within physiological ranges and relays this information to other brain loci to control body fluid homeostasis [11,12]. Nomura et al. recently discovered that Nax signals activated by high salt in OVLT are transmitted via OVLT-paraventricular nucleus(PVN)-rostral ventral lateral medulla(RVLM) neural pathway to enhance sympathetic nerve activity(SNA) and blood pressure(BP) [13]. Thus, in salt-induced hypertension, Nax-positive glial cells in SFO are likely to detect [Na+] and relay the signal to other nuclei. Of course, more research is required to test this speculation.
The force-from-lipid principle and its origin, a ‘what is true for E. coli is true for the elephant’ refrain
Published in Journal of Neurogenetics, 2022
The FFL story begins with MscL but will not end with Piezos. Even selfishly considering only the physiology and pathology of humans, many force-driven channels need to be investigated. E.g. TRPV4 apparently measures weight load on developing and mature bones. Mutations results in heritable bone-developmental and other diseases. Heterologously expressed TRPV4 has been shown to respond directly to patch-clamp pipet suctions (Loukin et al., 2009). More sensing mechanisms awaits further investigation; even more force-sensing molecules await discovery. What is the molecule in the arterial baroreceptor that measures blood pressure? What is the molecule in the circumventricular organ of the hypothalamus that measures blood osmolarity? What molecules tell us that our stomachs or our bladders are full? What other molecules underlie the large varieties of tactile sensations, from the first kiss to love-making?
Alzheimer’s disease and gastrointestinal microbiota; impact of Helicobacter pylori infection involvement
Published in International Journal of Neuroscience, 2021
Michael Doulberis, Georgios Kotronis, Dimitra Gialamprinou, Stergios A. Polyzos, Apostolis Papaefthymiou, Panagiotis Katsinelos, Jannis Kountouras
Alterations in overall diversity and the relative abundance of microbial species is connected with CNS autoimmunity. Gastrointestinal microbiota imbalance can induce inflammation that is connected with the pathogenesis of metabolic syndrome (MetS)- related disorders including AD. Moreover, gastrointestinal microbiota can secrete large amounts of amyloids and lipopolysaccharides, which might contribute to the modulation of signaling pathways and the production of pro-inflammatory cytokines that are associated with AD pathogenesis and cerebral amyloid accumulation. These pro-inflammatory cytokines might relay peripheral immune signals to the CNS via sensory nerves, circumventricular organs and BBB cells. As a consequence, the brain could induce mediators, triggering additional immune modulation dysfunction, and activating inflammation through interaction with immune cells, thereby leading to neurodegeneration [1,4,9,12–14].