The role of Serine Proteases and Serine Protease Inhibitors in the migration of Gonadotropin-Releasing Hormone neurons

BACKGROUND: Mechanisms regulating neuronal migration during development remain largely undefined. Extracellular matrix cues, target site released factors, and components of the migratory neurons themselves are likely all coordinated in time and space directing neurons to their appropriate locations. We have studied the effects of proteases and their inhibitors on the extracellular matrix and the consequences to the migration of gonadotropin releasing hormone (GnRH) neurons in the embryonic chick. Chick GnRH neurons differentiate in the olfactory epithelium, migrate along the olfactory nerve and enter the forebrain. The accessibility of this coherent cell group make it amenable for studying protease/inhibitor roles in migratory processes. RESULTS: Affigel blue beads were used to deliver a serine protease inhibitor, protease nexin-1 (PN-1), and a target protease, trypsin, to the olfactory epithelium coincident with initiation of GnRH neuronal migration. PN-1 inhibited neuronal migration while trypsin accelerated their transit into the CNS. Prior to initiation of migration, neither PN-1 nor trypsin altered the timing of neuronal exit. Trypsin did, however, accelerate the timing of neuronal crossing into the nerve-forebrain junction. CONCLUSIONS: These data support the hypothesis that protease activity modulates neuronal movements across barriers. Moreover, the data suggest, for the first time, that aspects of GnRH neuronal migration may be cell autonomous but modulated by ECM alterations

Potential sites of interaction between catecholamines and LHRH in the sheep brain

A combined immunoperoxidase/immunofluorescence procedure was used to examine potential sites of overlap between catecholamine and LHRH systems in the brains of ewes sacrificed during either anestrous or the breeding season. Cells and fibers immunoreactive for either tyrosine hydroxylase (TH) or dopamine-beta-hydroxylase (DBH) were visualized in the same sections as immunopositive LHRH perikarya and fibers. TH- and DBH-positive varicosities in the preoptic area and anterior hypothalamus appeared to contact both LHRH cell bodies and their dendrites. Clusters of TH-positive cells and fibers were found in the organum vasculosum of the lamina terminalis, and partially overlapped the location of immunoreactive LHRH fibers in that structure. Immunoreactive TH and LHRH fibers were densely interspersed within the zona externa of the median eminence, particularly within its lateral portion. No obvious qualitative differences were apparent in either the distribution of catecholamine cells and fibers or their overlap with LHRH elements between the brains of anestrous and breeding season ewes. These observations suggest the possibility of catecholaminergic synaptic inputs onto LHRH neurons in the ewe, as well as the potential for interaction between catecholamines and LHRH at the level of the median eminence. p]LHRH Sheep Immunocytochemistry Tyrosine hydroxylase Dopamine-beta-hydroxylasePeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27455/1/0000495.pd

Male gays in the female gaze: women who watch m/m pornography

This paper draws on a piece of wide-scale mixed-methods research that examines the motivations behind women who watch gay male pornography. To date there has been very little interdisciplinary research investigating this phenomenon, despite a recent survey by PornHub (one of the largest online porn sites in the world) showing that gay male porn is the second most popular choice for women porn users out of 25+ possible genre choices. While both academic literature and popular culture have looked at the interest that (heterosexual) men have in lesbian pornography, considerably less attention has been paid to the consumption of gay male pornography by women. Research looking at women's consumption of pornography from within the Social Sciences is very focused around heterosexual (and, to a lesser extent, lesbian) pornography. Research looking more generally at gay pornography/erotica (and the subversion of the ‘male gaze’/concept of ‘male as erotic object’) often makes mention of female interest in this area, but only briefly, and often relies on anecdotal or observational evidence. Research looking at women's involvement in slashfic (primarily from within media studies), while very thorough and rich, tends to view slash writing as a somewhat isolated phenomenon (indeed, in her influential article on women's involvement in slash, Bacon-Smith talks about how ‘only a small number’ of female slash writers and readers have any interest in gay literature or pornography more generally, and this phenomenon is not often discussed in more recent analyses of slash); so while there has been a great deal of very interesting research done in this field, little attempt has been made to couch it more generally within women's consumption and use of pornography and erotica or to explore what women enjoy about watching gay male pornography. Through a series of focus groups, interviews, and an online questionnaire (n = 275), this exploratory piece of work looks at what women enjoy about gay male pornography, and how it sits within their consumption of erotica/pornography more generally. The article investigates what this has to say about the existence and nature of a ‘female gaze’

Suicide and Suicide Risk in Lesbian, Gay, Bisexual, and Transgender Populations: Review and Recommendations

Despite strong indications of elevated risk of suicidal behavior in lesbian, gay, bisexual, and transgender people, limited attention has been given to research, interventions or suicide prevention programs targeting these populations. This article is a culmination of a three-year effort by an expert panel to address the need for better understanding of suicidal behavior and suicide risk in sexual minority populations, and stimulate the development of needed prevention strategies, interventions and policy changes. This article summarizes existing research findings, and makes recommendations for addressing knowledge gaps and applying current knowledge to relevant areas of suicide prevention practice

Reconstructing the Deep Population History of Central and South America

We report genome-wide ancient DNA from 49 individuals forming four parallel time transects in Belize, Brazil, the Central Andes, and the Southern Cone, each dating to at least 9,000 years ago. The common ancestral population radiated rapidly from just one of the two early branches that contributed to Native Americans today. We document two previously unappreciated streams of gene flow between North and South America. One affected the Central Andes by 4,200 years ago, while the other explains an affinity between the oldest North American genome associated with the Clovis culture and the oldest Central and South Americans from Chile, Brazil, and Belize. However, this was not the primary source for later South Americans, as the other ancient individuals derive from lineages without specific affinity to the Clovis-associated genome, suggesting a population replacement that began at least 9,000 years ago and was followed by substantial population continuity in multiple regions

Transancestral mapping and genetic load in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease with marked gender and ethnic disparities. We report a large transancestral association study of SLE using Immunochip genotype data from 27,574 individuals of European (EA), African (AA) and Hispanic Amerindian (HA) ancestry. We identify 58 distinct non-HLA regions in EA, 9 in AA and 16 in HA (B50% of these regions have multiple independent associations); these include 24 novel SLE regions (Po5 10 8), refined association signals in established regions, extended associations to additional ancestries, and a disentangled complex HLA multigenic effect. The risk allele count (genetic load) exhibits an accelerating pattern of SLE risk, leading us to posit a cumulative hit hypothesis for autoimmune disease. Comparing results across the three ancestries identifies both ancestry-dependent and ancestry-independent contributions to SLE risk. Our results are consistent with the unique and complex histories of the populations sampled, and collectively help clarify the genetic architecture and ethnic disparities in SL

Artificial cell research as a field that connects chemical, biological and philosophical questions

This review article discusses the interdisciplinary nature and implications of artificial cell research. It starts from two historical theories: Gánti's chemoton model and the autopoiesis theory by Maturana and Varela. They both explain the transition from chemical molecules to biological cells. These models exemplify two different ways in which disciplines of chemistry, biology and philosophy can profit from each other. In the chemoton model, conclusions from one disciplinary approach are relevant for the other disciplines. In contrast, the autopoiesis model itself (rather than its conclusions) is transferred from one discipline to the other. The article closes by underpinning the relevance of artificial cell research for philosophy with reference to the on-going philosophical debates on emergence, biological functions and biocentrism

The genetic architecture of the human cerebral cortex

The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder

Brain multiplexes reveal morphological connectional biomarkers fingerprinting late brain dementia states

Accurate diagnosis of mild cognitive impairment (MCI) before conversion to Alzheimer’s disease (AD) is invaluable for patient treatment. Many works showed that MCI and AD affect functional and structural connections between brain regions as well as the shape of cortical regions. However, ‘shape connections’ between brain regions are rarely investigated -e.g., how morphological attributes such as cortical thickness and sulcal depth of a specific brain region change in relation to morphological attributes in other regions. To fill this gap, we unprecedentedly design morphological brain multiplexes for late MCI/AD classification. Specifically, we use structural T1-w MRI to define morphological brain networks, each quantifying similarity in morphology between different cortical regions for a specific cortical attribute. Then, we define a brain multiplex where each intra-layer represents the morphological connectivity network of a specific cortical attribute, and each inter-layer encodes the similarity between two consecutive intra-layers. A significant performance gain is achieved when using the multiplex architecture in comparison to other conventional network analysis architectures. We also leverage this architecture to discover morphological connectional biomarkers fingerprinting the difference between late MCI and AD stages, which included the right entorhinal cortex and right caudal middle frontal gyrus

Multimodal and Multiscale Deep Neural Networks for the Early Diagnosis of Alzheimer’s Disease using structural MR and FDG-PET images

Alzheimer’s Disease (AD) is a progressive neurodegenerative disease where biomarkers for disease based on pathophysiology may be able to provide objective measures for disease diagnosis and staging. Neuroimaging scans acquired from MRI and metabolism images obtained by FDG-PET provide in-vivo measurements of structure and function (glucose metabolism) in a living brain. It is hypothesized that combining multiple different image modalities providing complementary information could help improve early diagnosis of AD. In this paper, we propose a novel deep-learning-based framework to discriminate individuals with AD utilizing a multimodal and multiscale deep neural network. Our method delivers 82.4% accuracy in identifying the individuals with mild cognitive impairment (MCI) who will convert to AD at 3 years prior to conversion (86.4% combined accuracy for conversion within 1–3 years), a 94.23% sensitivity in classifying individuals with clinical diagnosis of probable AD, and a 86.3% specificity in classifying non-demented controls improving upon results in published literature