bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interneurons are the local targets of hippocampal inhibitory cells which project to the medial septum
Authors: Gulyás A. I. , Hájos N. , Katona I. , Freund T. F. 
Published: May 2003

AbstractA subset of GABAergic neurons projecting to the medial septum has long been described in the hippocampus. However, the lack of information about their local connectivity pattern or their correspondence with any of the well‐established hippocampal interneuron types has hampered the understanding of their functional role. Retrograde tracing combined with immunostaining for neurochemical markers in the adult rat hippocampus showed that nearly all hippocampo‐septal (HS) neurons express somatostatin (>95%) and, in the hilus and CA3 stratum lucidum, many contain calretinin (>45%). In contrast, in stratum oriens of the CA1 and CA3 subfields, the majority of HS neurons contain somatostatin (>86%) and calbindin (>73%), but not calretinin. Because somatostatin‐positive hippocampal interneurons have been most extensively characterized in the stratum oriens of CA1, we focused our further analysis on HS cells found in this region. In 18–20‐day‐old rats, intracellularly filled CA1‐HS cells had extensive local axon collaterals crossing subfield boundaries and innervating the CA3 region and the dentate gyrus. Electron microscopic analysis provided evidence that the axon terminals of CA1‐HS cells form symmetrical synapses selectively on GABAergic interneurons, both locally and in the CA3 region. In addition, double retrograde labelling experiments revealed that many CA1‐HS neurons of the dorsal hippocampus also have collateral projections to the ventral hippocampus. Thus, CA1‐HS cells innervate inhibitory interneurons locally and in remote hippocampal regions, in addition to targeting mostly GABAergic neurons in the medial septum. This dual projection with striking target selectivity for GABAergic neurons may be ideally suited to synchronize neuronal activity along the septo‐hippocampal axis.
Neural correlates of memorized associations and cued movements in archistriatum of the domestic chick
Authors: Aoki Naoya , Izawa Ei‐Ichi , Yanagihara Shin , Matsushima Toshiya 
Published: May 2003

AbstractThe archistriatum mediates a neural pathway from the medial part of intermediate hyperstriatum ventrale (in the dorsal pallium) to the lobus parolfactorius (in the medial striatum), thus is possibly involved in memory formation in the domestic chick. To elucidate the functional roles, we examined single neuron activities from archistriatum in unconstrained chicks during execution of a GO/NOGO task. In this task, a brief motor sound was given as initial cue, and immediately followed by presentation of a coloured bead. Chick was required to recall the memorized associations between the colour and reward, and pecked at the bead to gain food after a delay (GO trials) or stayed not pecking (NOGO trials). The ventral part of intermediate archistriatum proved to contain a group of neurons that selectively responded to the reward‐associated colours before the reward was actually presented, possibly coding the memorized associations. Another group of neurons fired during the reward period, thus could code aspects of the food reward. Yet another group of neurons started to fire immediately on the cue sound and prior to the cued movements nonselectively in both GO and NOGO trials, thus could be involved in the sensori‐motor link between the sound and the targeted body movements. It is concluded that even a subregion of archistriatum contains diverse neural codes for memorized associations and food rewards, and neural codes of movements cued by sounds, suggesting that archistriatum is a complex of different functional systems, possibly corresponding to striatum, limbic amygdala, and prefrontal cortex in mammals.
Early establishment of multiple release site connectivity between interneurons and pyramidal neurons in the developing hippocampus
Authors: Groc Laurent , Gustafsson Bengt , Hanse Eric 
Published: May 2003

AbstractThe strength of the synaptic transmission between two neurons critically depends on the number of release sites connecting the neurons. Here we examine the development of connectivity between γ‐aminobutyric acid (GABA)ergic interneurons and CA1 pyramidal neurons in the hippocampus. GABAergic postsynaptic currents (PSCs) were recorded in whole‐cell voltage‐clamped CA1 pyramidal neurons. By comparing spontaneous and miniature (action potential‐independent) GABAergic PSCs, we found that multiple release site connectivity is established already at the first postnatal day and that the degree of connectivity remains unaltered into adulthood. During the same time there is a dramatic increase in the number of GABAergic synapses on each pyramidal neuron as indicated by the increase in frequency of miniature GABAergic PSCs. These results indicate that during development a given interneuron contacts an increasing number of target pyramidal neurons but with the same multiple release site connectivity. It has been shown previously that the connectivity between CA3 and CA1 pyramidal neurons is initially restricted to one release site, and develops gradually. The present result thus suggests different mechanisms to govern the maturation of excitatory and inhibitory synaptic transmissions.
Bioactivity of a peptide derived from acetylcholinesterase: electrophysiological characterization in guinea‐pig hippocampus
Authors: Bon Christelle L. M. , Greenfield Susan A. 
Published: May 2003

AbstractAcetylcholinesterase is well known to have noncholinergic functions. Only recently, however, has the salient part been identified of the molecule responsible for these nonclassical actions, a peptide of 14 amino acids towards the C‐terminus of acetylcholinesterase. The aim of this study was to test the bioactivity of this ‘acetylcholinesterase‐peptide’ using intracellular recordings in guinea‐pig hippocampal slices. In the presence of tetrodotoxin, acetylcholinesterase‐peptide alone affected neither the membrane potential nor the input resistance of CA1 neurons; however, a modulatory action was observed, as a concentration‐dependent decrease of N‐methyl‐d‐aspartic acid‐induced depolarization. When calcium potentials were elicited by a depolarizing current pulse, application of acetylcholinesterase‐peptide increased or reduced the degree of calcium spike firing in, respectively, the presence or absence of the N‐methyl‐d‐aspartic acid antagonist d(–)‐2‐amino‐5‐phosphonopentanoic acid. In contrast, a peptide derived from the equivalent region of butyrylcholinesterase, which also hydrolyses acetylcholine, had no effect. In conclusion, acetylcholinesterase‐peptide has a selective bioactivity in the hippocampus; it could thus offer new ways of targeting mechanisms of calcium‐induced neurotoxicity.
Micromixers to produce cosmetic emulsions
Authors: Tromeur M. , Mahé C. , Schwesinger N. , Tranchant J.‐F. 
Published: May 2003

SynopsisIn the cosmetics industry, emulsions play a key‐role in active solubilization and texture/efficacy optimization. However, depending on their physico‐chemical properties, the active ingredients are often more stable in a single phase: for example, Vitamin A is more stable in an oily phase than in a water phase.We have developed a special mixing device which produces an emulsion in the body of the pump, immediately before application on the skin. The mixing unit consists of two silicon chips. Each chip has several Y‐shaped microchannels and intersections etched on its upper surface. When the two etched surfaces are bonded together, they produce series of interconnecting micromixing elements which permit the repeat mixing of the two phases, thus producing an extremely homogenous emulsion. These micromixers require carefully designed formulae in which the physico‐chemical properties of each raw material are essential to obtain a spontaneous emulsion. This device has been incorporated into a spray pack and optimized to deliver the spontaneous emulsion when finger pressure is applied.
A keratinocytes–melanocytes coculture system for the evaluation of active ingredients' effects on UV‐induced melanogenesis
Authors: Nicolaÿ J.‐F. , Levrat B. 
Published: May 2003

SynopsisA new experimental design, more reliable for in vitro testing of active ingredients' effect on ultraviolet (UV)‐induced melanogenesis has been carried out. It uses a bicompartmental coculture system where cell communication between keratinocytes and melanocytes can take place. Thus, this experimental situation enables to monitor the effect of biological agents released by both cell types on melanogenesis and the interference of tested compounds with this ‘paracrine linkage’. Experiments with UVB‐irradiated cocultures show the importance of cell communication in the melanogenic response. In this model, the endogenous mediator, nitric oxide (NO), increased melanin production. Different compounds were tested in the coculture system, and comparison with data obtained from irradiated monocultures of melanocytes enables to distinguish a specific effect on cell communication. In addition, this more close‐to‐reality experimental model proved to provide a valuable first approach for the assessment of the ‘bioavailability’ of the tested substances. Finally, the effect of an innovative photoprotective agent capable of ‘boosting’ UV‐induced melanogenic cell communication is presented.
Enzymatic production of atranorin: a component of the oak moss absolute by immobilized lichen cells
Authors: Vicente C. , Fontaniella B. , Millanes A. M. , Sebastián B. , Legaz M. E. 
Published: May 2003

SynopsisCells of the lichen, Evernia prunastri, immobilized in calcium alginate were able to produce the depside atranorin from acetate. The synthesis of the depside was enhanced by molecular oxygen and NADH. This enhancement suggested the participation of an oxidase and an alcohol dehydrogenase to produce an aldehyde‐substituted phenolic acid, hematommic acid, as the most probable precursor of atranorin. The participation of both enzymes was confirmed by loading immobilized cells with sodium azide, an inhibitor of several metallo‐oxidases, and pyrazole, an inhibitor of alcohol dehydrogenase, which impeded atranorin production and accumulated β‐methyl orsellinate (after azide loading) or its alcohol derivative (after pirazole treatment).
Irritation cutanée et vitesse de propagation d'ondes ultrasonores
Authors: Uhoda E. , Piérard G. E. 
Published: May 2003

SynopsisCutaneous irritation is a stereotyped response of the skin to any physical or chemical insult. Its main manifestations encompass inflammatory erythema and an alteration of the cutaneous microrelief showing increased roughness, dehydration and erratic desquamation. Several instrumental methods can indirectly assess the issues of cutaneous irritation on human stratum corneum.The aim of the present study was to measure the speed of propagation of ultrasound shear waves in the skin irritated by anionic surfactants. The study was performed in 25 healthy subjects of both sexes. Occlusive patches of a 10% solution of anionic surfactants were applied to a forearm of each volunteer. The other forearm served as an untreated control site. Patches remained in place for 24 h. Three hours later, another patch was placed again for 21 h. Resonance running time measurements (RRTM) of the ultrasound shear wave were performed using a Reviscometer® RVM 600. Measurements were performed at entry in the study and 2 days after removing the second patch.Desquamative xerosis was obvious at the sites patched with the surfactant solution. RRTM values were significantly (P < 0.0001) lower than those at the control site. Hence, the speed of propagation of ultrasound shear waves was shown to be increased at an irritated site compared to an intact site.In conclusion, this study shows that the propagation speed of ultrasounds is influenced by the skin surface nature, being considerably increased in skin altered by surfactants.
In vivo study of the physiological impact of stratum corneum sampling methods
Authors: Rosado C. , Rodrigues L. M. 
Published: May 2003

Synopsis Background: Several methods have been developed to study in vivo the stratum corneum with minimal ‘invasion’. Cyanoacrylate adhesives employed in skin surface biopsy (SSB) and tape stripping are commonly used techniques that can be applied to study the different layers of the epidermis or even to permeation studies. However, depending on the type of adhesive tape used and pressure applied, different information is gathered. Aim: The purpose of this study was to identify and compare the impact of both techniques in the normal skin physiology to further establish its potential usefulness and limitations. Methods: Alterations were focused on basic structural related properties, such as epidermal barrier function (assessed by transepidermal water loss evaporimetry) and flow related changes (by laser Doppler velocimetry and colourimetry). Results/conclusions: Results indicate a more pronounced impact of SSB than that of tape stripping, attributable to the removal of a thicker layer of cells. The intertechnique correlation coefficients were good between transepidermal water loss and colourimetry, but poorer between these techniques and laser doppler flowmetry, which probably reflects the difficulties associated with this technique.
Multicentre comparison of skin hydration in terms of physical‐, physiological‐ and product‐dependent parameters by the capacitive method (Corneometer CM 825)
Authors: Heinrich U. , Koop U. , Leneveu‐Duchemin M.‐C. , Osterrieder K. , Bielfeldt S. , Chkarnat C. , Degwert J. , Häntschel D. , Jaspers S. , Nissen H.‐P. , Rohr M. , Schneider G. , Tronnier H. 
Published: May 2003

SynopsisA multicentre study for measuring skin hydration with 349 volunteers was carried out in six different laboratories. The purpose of the study was to investigate physical‐, physiological‐ and product‐dependent parameters of three test emulsions (base, base + moisturizer and base + moisturizer + lipids) in a double‐blind study. A comparison between analogous and digital sensor technology of the Corneometer CM825 was examined. Here, a clear relationship between both sensor types could be highlighted. A vital point of the study was the division of the test subjects according to their skin type. To get more objective limits for three different skin types – very dry, dry and normal skin – visual expert evaluation, self‐assessment and hydration measurements were analysed by means of statistical methods. The moisture‐related skin types were determined as follows: very dry skin was characterized with corneometer units below 30, dry skin between 30 and 40 and normal skin higher than 40 a.u. (arbitrary units). The efficacy of the three test emulsions was examined in relation to the mentioned skin types. Analysing the measured data of all test centres, a clear dependency of skin physiology (skin type) and product efficacy became evident. The drier the skin, the higher the increase of hydration. The product performance of the three test emulsions compared to the untreated control resulted in a significant increase of skin hydration in all measuring centres. The evaluation of a product ranking showed a good differentiation between the basic emulsion and the two other products. An increase of efficacy by adding lipids could be observed in four of six centres. The important influence of the skin type of the volunteers on the degree of product performance, as demonstrated in this study, should be especially considered when drawing up guidelines for efficacy testing.
In vitro stimulation of synthesis of key DEJ constituents in a reconstructed skin model: a quantitative study
Authors: Reymermier C. , Guezennec A. , Branka J. E. , Guesnet J. , Perrier E. 
Published: May 2003

SynopsisFighting skin ageing is one of the major targets of cosmetology research. However, traditional approaches to skin ageing using stimulation of basal keratinocyte proliferation and fibroblastic neosynthesis appear today to be incomplete, particularly considering changes occurring at the dermal–epidermal junction (DEJ) during the course of ageing. Unfortunately, the lack of in vitro model limits the exploration process of the phenomena of DEJ ageing, and particularly the evaluation of the changes of key components, that are laminin‐5, types IV and VII collagens. The aim of this work was to provide an in vitro model of reconstructed skin, base for new dosage and identification methods for qualitative and quantitative analysis of the key components of DEJ. Reverse transcriptase‐polymerase chain reaction (RT‐PCR) and quantitative RT‐PCR were successfully applied to this model to analyse mRNA of laminin‐5, types IV and VII collagens and their variation in ‘young’ and ‘mature’ reconstructed skin model. Finally, this model was used to test the activity of ingredients for cosmetic application, in order to modulate the expression of the major components of DEJ. To conclude, we demonstrated that this in vitro model of reconstructed young and mature skin provides a useful tool to get into the biology of the DEJ, key structure of the skin, and specifically into its dynamic changes during the ageing process.
Trends in stratum corneum research and the management of dry skin conditions
Authors: Rawlings A. V. 
Published: May 2003

SynopsisThe structure, composition, formation and function of the stratum corneum have been the subject of intense research over the last few decades. As has become apparent, stratum corneum barrier function is not only dependent on one single component but also on its total architecture. Recent developments in understanding lipid composition have led to a new ceramide nomenclature system, a new proposal for a molecular model of the interactions between ceramides, cholesterol and fatty acids, and the demonstration of the presence of crystalline orthorhombic and gel hexagonal lipid phases in the stratum corneum. Linoleate‐containing ceramide one, now known as CER EOS, have been shown to be essential for the formation of the 13 nm long periodicity phase (LPP) observed by electron microscopy and X‐ray diffraction studies, whereas long‐chain fatty acids are important for the formation of the crystalline lipid phases essential for barrier function. The role of the corneocyte envelope, its constituent proteins and its transglutaminase‐mediated maturation processes have been shown to be essential for good skin condition. Several proteases may have a role in corneodesmolysis, particularly serine and cathepsin‐like enzymes. Novel filaggrin polymorphisms have been identified that may be involved in the expression of a dry skin phenotype. Disturbances in lipid packing states, reduction in ceramide levels (particularly the phytosphingosine‐containing ceramides), reductions in the levels of long‐chain fatty acids and loss of the LPP largely account for the perturbations in lipid structure that occur in dry skin. The reduced corneodesmolysis that occurs in this xerotic skin disorder is now well accepted and is caused by reductions in the levels and activities of stratum corneum proteases together with elevated levels of corneodesmosomal glycoproteins in the superficial layers of the stratum corneum. Additionally, increased levels of fragile corneocytes are associated with reduced transglutaminase activity and corneocyte envelope cross‐linking events. However, in comparison with the advances in our understanding of the textural changes that occur in dry skin, the somatosensory changes are poorly understood and the itching associated with dry skin is still an under‐researched area. The unique biosensor role of the stratum corneum essential for a competent natural moisturizing barrier may also have a role to play in the action of anti‐ageing technologies by controlling the expression and secretion of epidermal cytokines and growth factors. Technologies to treat the surface textural skin problems, enhance the differentiation process, particularly lipid biosynthesis, and to control the somatosensory problems in dry skin have received much attention in the last decade. This paper will review the state of the art of stratum corneum biology and the trends in the management of dry skin.
Epidemiological and Clinical Characteristics of Migraine and Tension Type Headache in 1146 Females in Kayseri, Turkey
Authors: Köseoglu E , Naçar M , Talaslioglu A , çetinkaya F 
Published: May 2003

In a female population of Turkey (1146 adult females), some epidemiological and clinical characteristics of migraine and tension type headache and their subtypes were investigated. The relation of the headache severity to clinical characteristics were inquired. Migraine prevalence was found to be statistically higher in the 35-44 years age group ( P < 0.01) and those who were university graduates ( P < 0.001), married ( P < 0.01) and living in urban areas ( P < 0.01). Tension type headache was found to be higher in the 45-64 years age group ( P < 0.05). Chronic tension type headache patients were found to be older than episodic type ( P < 0.01) and frequently were in the lowest education level ( P < 0.05). Presence of impact on daily activities because of the severity of headache was found to be related to aggravation by physical activities ( P = 0.001) in tension type headache, with no clinical characteristics in migraine headache and on consideration of all headache patients with throbbing nature ( P < 0.05), aggravation on physical activities ( P = 0.001), nausea ( P < 0.01), vomiting ( P < 0.05) and phonophobia ( P < 0.05).
Nociceptive Temporalis Inhibitory Reflexes Evoked by Co2-Laser Stimulation in Tension-Type Headache
Authors: de Tommaso M , Guido M , Libro G , Losito L , Sciruicchio V , Specchio LM , Puca F 
Published: May 2003

The aim of the study was to evaluate the laser-induced suppression periods of the temporalis muscle in patients with tension-type headache, compared with the pattern of temporalis activity suppression induced by electrical stimulation. Fifteen patients with chronic and 10 with episodic tension-type headaches were selected. Suppression periods were recorded simultaneously from both temporalis muscles using both electrical stimuli and CO2-laser stimuli. A significant reduction in the later electrically induced suppression period was found in both tension-type headache groups. Laser stimulation induced a first suppression period (LSP1) with a latency of about 50 ms in all patients. The features of LSP1 were similar across groups. The LSP1 should correspond to the first suppression period induced by electrical stimulus, which is partly a nociceptive response, whereas the second period seemed negligibly linked with the activation of pain-related afferents, though probably their activation may contribute to increase the reflex duration and to emphasize abnormalities in tension-type headache.