48 research outputs found
Ghrelin Modulates the fMRI BOLD Response of Homeostatic and Hedonic Brain Centers Regulating Energy Balance in the Rat
The orexigenic gut-brain peptide, ghrelin and its G-protein coupled receptor, the growth hormone secretagogue receptor
1a (GHS-R1A) are pivotal regulators of hypothalamic feeding centers and reward processing neuronal circuits of the brain.
These systems operate in a cooperative manner and receive a wide array of neuronal hormone/transmitter messages and
metabolic signals. Functional magnetic resonance imaging was employed in the current study to map BOLD responses to
ghrelin in different brain regions with special reference on homeostatic and hedonic regulatory centers of energy balance.
Experimental groups involved male, ovariectomized female and ovariectomized estradiol-replaced rats. Putative modulation
of ghrelin signaling by endocannabinoids was also studied. Ghrelin-evoked effects were calculated as mean of the BOLD
responses 30 minutes after administration. In the male rat, ghrelin evoked a slowly decreasing BOLD response in all studied
regions of interest (ROI) within the limbic system. This effect was antagonized by pretreatment with GHS-R1A antagonist
JMV2959. The comparison of ghrelin effects in the presence or absence of JMV2959 in individual ROIs revealed significant
changes in the prefrontal cortex, nucleus accumbens of the telencephalon, and also within hypothalamic centers like the
lateral hypothalamus, ventromedial nucleus, paraventricular nucleus and suprachiasmatic nucleus. In the female rat, the
ghrelin effects were almost identical to those observed in males. Ovariectomy and chronic estradiol replacement had no
effect on the BOLD response. Inhibition of the endocannabinoid signaling by rimonabant significantly attenuated the
response of the nucleus accumbens and septum. In summary, ghrelin can modulate hypothalamic and mesolimbic
structures controlling energy balance in both sexes. The endocannabinoid signaling system contributes to the
manifestation of ghrelin’s BOLD effect in a region specific manner. In females, the estradiol milieu does not influence the
BOLD response to ghrelin
Canonical BMP–Smad Signalling Promotes Neurite Growth in Rat Midbrain Dopaminergic Neurons
Ventral midbrain (VM) dopaminergic (DA) neurons project to the dorsal striatum via the nigrostriatal pathway to regulate voluntary movements, and their loss leads to the motor dysfunction seen in Parkinson’s disease (PD). Despite recent progress in the understanding of VM DA neurogenesis, the factors regulating nigrostriatal pathway development remain largely unknown. The bone morphogenetic protein (BMP) family regulates neurite growth in the developing nervous system and may contribute to nigrostriatal pathway development. Two related members of this family, BMP2 and growth differentiation factor (GDF)5, have neurotrophic effects, including promotion of neurite growth, on cultured VM DA neurons. However, the molecular mechanisms regulating their effects on DA neurons are unknown. By characterising the temporal expression profiles of endogenous BMP receptors (BMPRs) in the developing and adult rat VM and striatum, this study identified BMP2 and GDF5 as potential regulators of nigrostriatal pathway development. Furthermore, through the use of noggin, dorsomorphin and BMPR/Smad plasmids, this study demonstrated that GDF5- and BMP2-induced neurite outgrowth from cultured VM DA neurons is dependent on BMP type I receptor activation of the Smad 1/5/8 signalling pathway
Connecting town and country A study of joint working and partnerships between urban and rural areas in England
SIGLEAvailable from British Library Document Supply Centre-DSC:9299.390(18) / BLDSC - British Library Document Supply CentreGBUnited Kingdo
European Society of Cardiology Heart Failure Association Standards for delivering heart failure care
The management of heart failure (HF) is complex. As a consequence, most cardiology society guidelines now state that HF care should be delivered in a multiprofessional manner. The evidence base for this approach now means that the establishment of HF management programmes is a priority. This document aims to summarize the key elements which should be involved in, as well as some more desirable features which can improve the delivery of care in a HF management programme, while bearing in mind that the specifics of the service may vary from site to site. We envisage a situation whereby all patients have access to the best possible care, including improved access to palliative care services, informed by and responsive to advances in diagnosis management and treatment. The goal should be to provide a 'seamless' system of care across primary and hospital care so that the management of every patient is optimal, no matter where they begin or continue their health-care journey