Search results for "CORT"

Nitric oxide/cGMP signaling via guanylyl cyclase isoform 1 modulates glutamate and GABA release in somatosensory cortex of mice

2017

Abstract In hippocampus, two guanylyl cyclases (NO-GC1 and NO-GC2) are involved in the transduction of the effects of nitric oxide (NO) on synaptic transmission. However, the respective roles of the NO-GC isoforms on synaptic transmission are less clear in other regions of the brain. In the present study, we used knock-out mice deficient for the NO-GC1 isoform (NO-GC1 KO) to analyze its role in the glutamatergic and GABAergic neurotransmission at pyramidal neurons in layers II/III of somatosensory cortex. NO-GC1 KO slices revealed reduced frequencies of miniature excitatory- and inhibitory-postsynaptic currents, increased paired-pulse ratios and decreased input–output curves of evoked signa…

The Severity of Acute Stress Is Represented by Increased Synchronous Activity and Recruitment of Hypothalamic CRH Neurons

2016

The hypothalamo-pituitary-adrenocortical (HPA) axis regulates stress physiology and behavior. To achieve an optimally tuned adaptive response, it is critical that the magnitude of the stress response matches the severity of the threat. Corticotropin-releasing hormone (CRH) released from the paraventricular nucleus of the hypothalamus is a major regulator of the HPA axis. However, how CRH-producing neurons in an intact animal respond to different stressor intensities is currently not known. Using two-photon calcium imaging on intact larval zebrafish, we recorded the activity of CRH cells, while the larvae were exposed to stressors of varying intensity. By combining behavioral and physiologic…

Pterostilbene Decreases the Antioxidant Defenses of Aggressive Cancer Cells In Vivo: A Physiological Glucocorticoids- and Nrf2-Dependent Mechanism

2016

Abstract Aims: Polyphenolic phytochemicals have anticancer properties. However, in mechanistic studies, lack of correlation with the bioavailable concentrations is a critical issue. Some reports had suggested that these molecules downregulate the stress response, which may affect growth and the antioxidant protection of malignant cells. Initially, we studied this potential underlying mechanism using different human melanomas (with genetic backgrounds correlating with most melanomas), growing in nude mice as xenografts, and pterostilbene (Pter, a natural dimethoxylated analog of resveratrol). Results: Intravenous administration of Pter decreased human melanoma growth in vivo. However, Pter, …

2018

OBJECTIVE The lack of pro-opiomelanocortin (POMC)-derived melanocortin peptides results in hypoadrenalism and severe obesity in both humans and rodents that is treatable with synthetic melanocortins. However, there are significant differences in POMC processing between humans and rodents, and little is known about the relative physiological importance of POMC products in the human brain. The aim of this study was to determine which POMC-derived peptides are present in the human brain, to establish their relative concentrations, and to test if their production is dynamically regulated. METHODS We analysed both fresh post-mortem human hypothalamic tissue and hypothalamic neurons derived from …

Dysregulation of C-X-C motif ligand 10 during aging and association with cognitive performance

2017

International audience; Chronic low-grade inflammation during aging (inflammaging) is associated with cognitive decline and neurodegeneration; however, the mechanisms underlying inflammaging are unclear. We studied a population (n = 361) of healthy young and old adults from the MyoAge cohort. Peripheral levels of C-X-C motif chemokine ligand 10 (CXCL10) was found to be higher in older adults, compared with young, and negatively associated with working memory performance. This coincided with an age-related reduction in blood DNA methylation at specific CpGs within the CXCL10 gene promoter. In vitro analysis supported the role of DNA methylation in regulating CXCL10 transcription. A polymorph…

Effects of PSA Removal from NCAM on the Critical Period Plasticity Triggered by the Antidepressant Fluoxetine in the Visual Cortex.

2016

Neuronal plasticity peaks during critical periods of postnatal development and is reduced towards adulthood. Recent data suggests that windows of juvenile-like plasticity can be triggered in the adult brain by antidepressant drugs such as Fluoxetine. Although the exact mechanisms of how Fluoxetine promotes such plasticity remains unknown, several studies indicate that inhibitory circuits play an important role. The polysialylated form of the neural cell adhesion molecules (PSA-NCAM) has been suggested to mediate the effects of Fluoxetine and it is expressed in the adult brain by mature interneurons. Moreover, the enzymatic removal of PSA by neuroaminidase-N not only affects the structure of…

Cortex-wide BOLD fMRI activity reflects locally-recorded slow oscillation-associated calcium waves.

2017

When a person is in a deep non-dreaming sleep, neurons in their brain alternate slowly between periods of silence and periods of activity. This gives rise to low-frequency brain rhythms called slow waves, which are thought to help stabilize memories. Slow wave activity can be detected on multiple scales, from the pattern of electrical impulses sent by an individual neuron to the collective activity of the brain’s entire outer layer, the cortex. But does slow wave activity in an individual group of neurons in the cortex affect the activity of the rest of the brain? To find out, Schwalm, Schmid, Wachsmuth et al. took advantage of the fact that slow waves also occur under general anesthesia, a…

Is there evidence for a rostral-caudal gradient in fronto-striatal loops and what role does dopamine play?

2018

Research has shown that the lateral prefrontal cortex (LPFC) may be hierarchically organized along a rostral-caudal functional gradient such that control processing becomes progressively more abstract from caudal to rostral frontal regions. Here, we briefly review the most recent functional MRI, neuropsychological, and electrophysiological evidence in support of a hierarchical LPFC organization. We extend these observations by discussing how such a rostral-caudal gradient may also exist in the striatum and how the dopaminergic system may play an important role in the hierarchical organization of fronto-striatal loops. There is evidence indicating that a rostral-caudal gradient of dopamine r…

Phylogenetic variation in cortical layer II immature neuron reservoir of mammals

2020

The adult mammalian brain is mainly composed of mature neurons. A limited amount of stem cell-driven neurogenesis persists in postnatal life and is reduced in large-brained species. Another source of immature neurons in adult brains is cortical layer II. These cortical immature neurons (cINs) retain developmentally undifferentiated states in adulthood, though they are generated before birth. Here, the occurrence, distribution and cellular features of cINs were systematically studied in 12 diverse mammalian species spanning from small-lissencephalic to large-gyrencephalic brains. In spite of well-preserved morphological and molecular features, the distribution of cINs was highly heterogeneou…

Updates to Finnish aphyllophoroid funga (Basidiomycota):new species and range extensions

2018

Abstract The knowledge of Finnish aphyllophoroid funga has increased substantially in recent years. In this article we present six species new to Finland: Cristinia (cf.) rhenana Grosse-Brauckm., Hyphodontiella hauerslevii K.H. Larss. & Hjortstam, Leptosporomyces montanus (Jülich) Ginns & M.N.L Lefebvre, Osteina obducta (Berk.) Donk, Sebacina helvelloides (Schwein.) Burt, and Tulasnella brinkmannii sensu lato Bres. The finding of Osteina obducta is the first record in Northern Europe. The article also contributes new records of 56 nationally rare species (maximum ten previous records in Finland). Additionally, we list 110 regionally new species, found for the first time from a certa…