Complementary subicular pathways to the anterior thalamic nuclei and mammillary bodies in the rat and macaque monkey brain

The origins of the hippocampal (subicular) projections to the anterior thalamic nuclei and mammillary bodies were compared in rats and macaque monkeys using retrograde tracers. These projections form core components of the Papez circuit, which is vital for normal memory. The study revealed a complex pattern of subicular efferents, consistent with the presence of different, parallel information streams, whose segregation appears more marked in the rat brain. In both species, the cells projecting to the mammillary bodies and anterior thalamic nuclei showed laminar separation but also differed along other hippocampal axes. In the rat, these diencephalic inputs showed complementary topographies in the proximal–distal (columnar) plane, consistent with differential involvement in object-based (proximal subiculum) and context-based (distal subiculum) information. The medial mammillary inputs, which arose along the anterior–posterior extent of the rat subiculum, favoured the central subiculum (septal hippocampus) and the more proximal subiculum (temporal hippocampus). In contrast, anterior thalamic inputs were largely confined to the dorsal (i.e. septal and intermediate) subiculum, where projections to the anteromedial nucleus favoured the proximal subiculum while those to the anteroventral nucleus predominantly arose in the distal subiculum. In the macaque, the corresponding diencephalic inputs were again distinguished by anterior–posterior topographies, as subicular inputs to the medial mammillary bodies predominantly arose from the posterior hippocampus while subicular inputs to the anteromedial thalamic nucleus predominantly arose from the anterior hippocampus. Unlike the rat, there was no clear evidence of proximal–distal separation as all of these medial diencephalic projections preferentially arose from the more distal subiculum

Shadowing in Inelastic Scattering of Muons on Carbon, Calcium and Lead at Low XBj

Nuclear shadowing is observed in the per-nucleon cross-sections of positive muons on carbon, calcium and lead as compared to deuterium. The data were taken by Fermilab experiment E665 using inelastically scattered muons of mean incident momentum 470 GeV/c. Cross-section ratios are presented in the kinematic region 0.0001 < XBj <0.56 and 0.1 < Q**2 < 80 GeVc. The data are consistent with no significant nu or Q**2 dependence at fixed XBj. As XBj decreases, the size of the shadowing effect, as well as its A dependence, are found to approach the corresponding measurements in photoproduction.Comment: 22 pages, incl. 6 figures, to be published in Z. Phys.

Clustered mutations in the GRIK2 kainate receptor subunit gene underlie diverse neurodevelopmental disorders (vol 108, pg 1692, 2021)

Neurolog

Translation of the article \u201cOn the fine structure of the pes Hippocampi major (with plates XII-XXIII)\u201d, by Camillo Golgi.

We have provided a translation of Golgi's original paper on the mammalian hippocampus (first published in 1883 and reprinted numerous times), along with a preface on its historical context. Golgi believed that this part of the cerebral hemisphere showed best the exact relationship between nerve cells and nerve fibers, the most important problem in 19th century neuroscience. Copyright \ua9 2001 Elsevier Science Inc

ANALYSIS OF ENERGY BROADENING IN CHARGED PARTICLE BEAMS

L'anomalie de distribution énergétique d'un faisceau d'ion monomères ou d'électrons est décrite par un modèle de file indienne à un paramètre, régi par l'émission de bruit de grenaille et par les interactions coulombiennes de paires. La dépendance de la largeur de la distribution et du décalage de l'énergie moyenne en fonction du courant, de la masse et de la tension est calculée. Une unification de plusieurs autres théories d'élargissement énergétique est faite à partir de la variation d'un paramètre libre qui représente des effets de champ liés à la géométrie. Une caractéristique unique du modèle présent est le fait que est inversement proportionnel à la charge.The anomalous energy distribution of a monomer ion or electron beam is described by a one parameter, single file model governed by shot noise emission and pairwise Coulomb interactions. The dependence of the width of the distribution and the shift in the mean energy on current, mass, and voltage is calculated. A unification of a number of other theories of energy broadening is made by variation of a free parameter that represents field-geometrical effects. A feature unique to the present model is that can be inversely related to charge

MECHANISMS OF ION FORMATION IN LIQUID METAL ION SOURCES

Un modèle théorique sur les sources d'ions à métal liquide a été développé qui permet d'expliquer : 1) la forme et les dimensions de la zone émissive ; 2) les mécanismes de formation des ions ; 3) les propriétés du faisceau ionique. Cet article est principalement consacré au § 2). Nous montrons que l'évaporation de champ est le mécanisme dominant de l'émission ionique et que l'existence d'ions de charge double ou multiple provient d'un phénomène de post-ionisation. Ce modèle est ensuite utilisé pour étudier les propriétés du faisceau émis, telles que : l'intensité angulaire, le déficit et la largeur énergétique, l'abondance relative d'ions de différents états de charge.We have developed a theoretical model of Liquid Metal Ion Source (LMIS) operation to explain consistently ; i) the shape and size of the ion emitting region, ii) the mechanisms of ion formation and iii) properties of the ion beam. In this paper we concentrate on ii), we find that field evaporation is the dominant ion formation mechanism and the occurrence of doubly or higher charged ions is attributed to a post-ionization mechanism. We discuss properties of the ion beams from LMIS such as angular intensity, energy deficit, energy spread and the relative abundance of different charge states in terms of our model of LMIS operation