Ventral tegmental (A10) system: neurobiology. 1. anatomy and connectivity

Introduction: The VTA contains the A 10 group of dopamine (DA) containing neurons. These neurons have ben grouped into nuclei to be found on the floor of the midbrain tegmentum - the Nucleus paranigralis (Npn), Nucleus interfasicularis (Nif), Nucleus parabrachialis (Npbp) and the Nucleus linearis (rostralis and caudalis) *. The VTA is traversed by many blood vessels and nerve fibers **. Close to its poorly defined borders are found DA (A8, A9, A11) and 5-HT containing neurons (B8). * Figures 2-4 show electron micrographs and drawings ** Figure 6 , electronmicrographs show neurovascular contacts in the rat and cat that could be used for, say, steroid hormone influence on neurotransmission. Efferent projections of the VTA can be divided into 5 subsystems. The mesorhombencephalic projects to other monoaminergic nucei, the cerebellum and a fine projection descends to other tegmental nuclei as far as the inferior olive. Fibers to the spinal cord havenot been demonstrated. The mesodiencephalic path projects to several thalamic and hypothalamic nuclei andpossibly the median eminence. Functionally important examples are the anterior hypothalamic-preoptic area, Nucleus medialis dorsalis and reuniens thalami. These two subsystems are largely non-dopaminergic. A minor mesostriatal projection is overshadowed by the large mesolimbic projection to the Nucleus accumbens, Tuberculum olfactorium, Septum lateralis and Nucleus interstitialis stria terminalis. There are also mesolimbic connections with several amygdaloid nuclei (especially centralis and basolateralis), the olfactory nuclei and Entorhinal cortex. A minor projection to the hippocampus has been detected. The mesocortical pathway projects to sensory (e.g. visual) motor, limbic (e.g. retrosplenial) and polysensory association coretices (e.g. prefrontal). Prefrontal, orbitofrontal (insular) and cingulate cortices receive the most marked innervation from the VTA. A more widespread presence of DA in other cortices of rodents becomes progressively more evident in carnivores and primates. Most but not all projections are unilateral (see Table VI for % crossed). Some neurons project to more than one area in mesodiencephalic, limbic and cortical systems. The majority of these fibers ascend in the medial forebrain bundle (MFB). Most areas receiving a projection from the VTA (DA or non-DA) project back to the VTA. The septo-hippocampal complex in particiular and the limbic system in general provide quantitatively much less feedback than other areas. The role of the VTA as a mediator of dialogue with the fronto - striatal and limbic / extrapyramidal system is discussed under the theme of " circuit " systems (Figure 11, 12 & 13). The large convergence of afferents to certain VTA projection areas (e.g., prefrontal, entorhinal cortices, lateral septum, central amygdala, habenula, and N. accumbens) is discussed under the theme of " convergence " systems (Figure 15 & 16). Animal studies clearly demonstrate that the VTA in general, and its DA projections in particular are strategically organized to influence integrative neural function in diverse regions of the meso-, di- and telencephalon

Resources and student achievement – evidence from a Swedish policy reform

This paper utilizes a policy change to estimate the effect of teacher density on student performance. We find that an increase in teacher density has a positive effect on student achievement. The baseline estimate – obtained by using the grade point average as the outcome variable – implies that resource increases corresponding to the class-size reduction in the STAR-experiment (i.e., a reduction of 7 students) improves performance by 2.6 percentile ranks (or 0.08 standard deviations). When we use test score data for men, potentially a more objective measure of student performance, the effect of resources appears to be twice the size of the baseline estimate.Student performance; teacher/student ratio; policy reform; differences-in-differences

Pregnancy and childbirth in English prisons : institutional ignominy and the pains of imprisonment

© 2020 The Authors. Sociology of Health & Illness published by John Wiley & Sons Ltd on behalf of Foundation for SHIL.With a prison population of approximately 9000 women in England, it is estimated that approximately 600 pregnancies and 100 births occur annually. Despite an extensive literature on the sociology of reproduction, pregnancy and childbirth among women prisoners is under‐researched. This article reports an ethnographic study in three English prisons undertaken in 2015‐2016, including interviews with 22 prisoners, six women released from prison and 10 staff members. Pregnant prisoners experience numerous additional difficulties in prison including the ambiguous status of a pregnant prisoner, physical aspects of pregnancy and the degradation of the handcuffed or chained prisoner during visits to the more public setting of hospital. This article draws on Erving Goffman's concepts of closed institutions, dramaturgy and mortification of self, Crewe et al.'s work on the gendered pains of imprisonment and Crawley's notion of ‘institutional thoughtlessness’, and proposes a new concept of institutional ignominy to understand the embodied situation of the pregnant prisoner.Peer reviewe

Testing the Gaussian expansion method in exactly solvable matrix models

The Gaussian expansion has been developed since early 80s as a powerful analytical method, which enables nonperturbative studies of various systems using `perturbative' calculations. Recently the method has been used to suggest that 4d space-time is generated dynamically in a matrix model formulation of superstring theory. Here we clarify the nature of the method by applying it to exactly solvable one-matrix models with various kinds of potential including the ones unbounded from below and of the double-well type. We also formulate a prescription to include a linear term in the Gaussian action in a way consistent with the loop expansion, and test it in some concrete examples. We discuss a case where we obtain two distinct plateaus in the parameter space of the Gaussian action, corresponding to different large-N solutions. This clarifies the situation encountered in the dynamical determination of the space-time dimensionality in the previous works.Comment: 30 pages, 15 figures, LaTeX; added references for section

A muon-track reconstruction exploiting stochastic losses for large-scale Cherenkov detectors

IceCube is a cubic-kilometer Cherenkov telescope operating at the South Pole. The main goal of IceCube is the detection of astrophysical neutrinos and the identification of their sources. High-energy muon neutrinos are observed via the secondary muons produced in charge current interactions with nuclei in the ice. Currently, the best performing muon track directional reconstruction is based on a maximum likelihood method using the arrival time distribution of Cherenkov photons registered by the experiment\u27s photomultipliers. A known systematic shortcoming of the prevailing method is to assume a continuous energy loss along the muon track. However at energies >1 TeV the light yield from muons is dominated by stochastic showers. This paper discusses a generalized ansatz where the expected arrival time distribution is parametrized by a stochastic muon energy loss pattern. This more realistic parametrization of the loss profile leads to an improvement of the muon angular resolution of up to 20% for through-going tracks and up to a factor 2 for starting tracks over existing algorithms. Additionally, the procedure to estimate the directional reconstruction uncertainty has been improved to be more robust against numerical errors

A C6orf10/LOC101929163 locus is associated with age of onset in C9orf72 carriers

The G4C2-repeat expansion in C9orf72 is the most common known cause of amyotrophic lateral sclerosis and frontotemporal dementia. The high phenotypic heterogeneity of C9orf72 patients includes a wide range in age of onset, modifiers of which are largely unknown. Age of onset could be influenced by environmental and genetic factors both of which may trigger DNA methylation changes at CpG sites. We tested the hypothesis that age of onset in C9orf72 patients is associated with some common single nucleotide polymorphisms causing a gain or loss of CpG sites and thus resulting in DNA methylation alterations. Combined analyses of epigenetic and genetic data have the advantage of detecting functional variants with reduced likelihood of false negative results due to excessive correction for multiple testing in genome-wide association studies. First, we estimated the association between age of onset in C9orf72 patients (n = 46) and the DNA methylation levels at all 7603 CpG sites available on the 450 k BeadChip that are mapped to common single nucleotide polymorphisms. This was followed by a genetic association study of the discovery (n = 144) and replication (n = 187) C9orf72 cohorts. We found that age of onset was reproducibly associated with polymorphisms within a 124.7 kb linkage disequilibrium