bluuebunny/crossref_metadata_2025_split huggingface dataset:
Oxytocin neuron activation in NCAM‐deficient mice: anatomical and functional consequences
Authors: Theodosis D. T. , Schachner M. , Neumann I. D. 
Published: January 2005

AbstractDuring stimulated neurosecretion in the rat, oxytocin neurons display a reduced glial coverage and receive an increased number of synapses, changes that are reversed on arrest of stimulation. We identified polysialic acid on the neural cell adhesion molecule (NCAM) as an important mediator of such plasticity. To investigate further the role of this cell surface glycoprotein, we examined the oxytocin system in mice genetically deficient in NCAM. First, ultrastructural analyses revealed that in wild‐type mice, the supraoptic nucleus (SON) underwent the same remodelling as in the rat because oxytocin neurons had a diminished astrocytic coverage and increased synaptic input during lactation or chronic salt loading. Surprisingly, the SON displayed this morphology in NCAM‐deficient mice as well, whether they were nongestating and hydrated, lactating or dehydrated. The oxytocin system in NCAM‐deficient mice was abnormally hyperactive, as illustrated by enhanced plasma and intranuclear concentrations of oxytocin and reduced anxiety‐related behaviour. Plasma oxytocin concentrations were also high in lactating NCAM‐deficient dams but certain parameters of lactation and maternal behaviour were impaired. NCAM‐deficient mice survived ingestion of 2% saline for 7 days and had increased plasma oxytocin but they did not cope with more severe osmotic challenges. Our observations highlight further the remarkable capacity of the adult oxytocin system to undergo neuronal and glial remodelling whenever it is activated. That lack of NCAM did not prevent remodelling indicates that NCAM can be substituted by other molecular mechanisms. Finally, while NCAM deficiency greatly enhanced oxytocin release, it led to impaired oxytocin‐dependent physiological and behavioural responses.
Rapid functional plasticity in the primary somatomotor cortex and perceptual changes after nerve block
Authors: Weiss Thomas , Miltner Wolfgang H. R. , Liepert Joachim , Meissner Winfried , Taub Edward 
Published: January 2005

AbstractThe mature human primary somatosensory cortex displays a striking plastic capacity to reorganize itself in response to changes in sensory input. Following the elimination of afferent return, produced by either amputation, deafferentation by dorsal rhizotomy, or nerve block, there is a well‐known but little‐understood ‘invasion’ of the deafferented region of the brain by the cortical representation zones of still‐intact portions of the brain adjacent to it. We report here that within an hour of abolishing sensation from the radial and medial three‐quarters of the hand by pharmacological blockade of the radial and median nerves, magnetic source imaging showed that the cortical representation of the little finger and the skin beneath the lower lip, whose intact cortical representation zones are adjacent to the deafferented region, had moved closer together, presumably because of their expansion across the deafferented area. A paired‐pulse transcranial magnetic stimulation procedure revealed a motor cortex disinhibition for two muscles supplied by the unaffected ulnar nerve. In addition, two notable perceptual changes were observed: increased two‐point discrimination ability near the lip and mislocalization of touch of the intact ulnar portion of the fourth finger to the neighbouring third finger whose nerve supply was blocked. We suggest that disinhibition within the somatosensory system as a functional correlate for the known enlargement of cortical representation zones might account for not only the ‘invasion’ phenomenon, but also for the observed behavioural correlates of the nerve block.
Gene expression profiling of the rat superior olivary complex using serial analysis of gene expression
Authors: Koehl Alexander , Schmidt Nicole , Rieger Anne , Pilgram Sara M. , Letunic Ivica , Bork Peer , Soto Florentina , Friauf Eckhard , Nothwang Hans Gerd 
Published: January 2005

AbstractThe superior olivary complex (SOC) is an auditory brainstem region that represents a favourable system to study rapid neurotransmission and the maturation of neuronal circuits. Here we performed serial analysis of gene expression (SAGE) on the SOC in 60‐day‐old Sprague–Dawley rats to identify genes specifically important for its function and to create a transcriptome reference for the subsequent identification of age‐related or disease‐related changes. Sequencing of 31 035 tags identified 10 473 different transcripts. Fifty‐seven per cent of the unique tags with a count greater than four were statistically more highly represented in the SOC than in the hippocampus. Among them were genes encoding proteins involved in energy supply, the glutamate/glutamine shuttle, and myelination. Approximately 80 plasma membrane transporters, receptors, channels, and vesicular transporters were identified, and 25% of them displayed a significantly higher expression level in the SOC than in the hippocampus. Some of the plasma membrane proteins were not previously characterized in the SOC, e.g. the purinergic receptor subunit P2X6and the metabotropic GABA receptor Gpr51. Differential gene expression between SOC and hippocampus was confirmed using RNAin situhybridization or immunohistochemistry. The extensive gene inventory presented here will alleviate the dissection of the molecular mechanisms underlying specific SOC functions and the comparison with other SAGE libraries from brain will ease the identification of promoters to generate region‐specific transgenic animals. The analysis will be part of the publicly available database ID‐GRAB.
Dissociable roles of the human somatosensory and superior temporal cortices for processing social face signals
Authors: Pourtois Gilles , Sander David , Andres Michael , Grandjean Didier , Reveret Lionel , Olivier Etienne , Vuilleumier Patrik 
Published: January 2005

AbstractFaces are multi‐dimensional stimuli bearing important social signals, such as gaze direction and emotion expression. To test whether perception of these two facial attributes recruits distinct cortical areas within the right hemisphere, we used single‐pulse transcranial magnetic stimulation (TMS) in healthy volunteers while they performed two different tasks on the same face stimuli. In each task, two successive faces were presented with varying eye‐gaze directions and emotional expressions, separated by a short interval of random duration. TMS was applied over either the right somatosensory cortex or the right superior lateral temporal cortex, 100 or 200 ms after presentation of the second face stimulus. Participants performed a speeded matching task on the second face during one of two possible conditions, requiring judgements about either gaze direction or emotion expression (same/different as the first face). Our results reveal a significant task–stimulation site interaction, indicating a selective TMS‐related interference following stimulations of somatosensory cortex during the emotional expression task. Conversely, TMS of the superior lateral temporal cortex selectively interfered with the gaze direction task. We also found that the interference effect was specific to the stimulus content in each condition, affecting judgements of gaze shifts (not static eye positions) with TMS over the right superior temporal cortex, and judgements of fearful expressions (not happy expressions) with TMS over the right somatosensory cortex. These results provide for the first time a double dissociation in normal subjects during social face recognition, due to transient disruption of non‐overlapping brain regions. The present study supports a critical role of the somatosensory and superior lateral temporal regions in the perception of fear expression and gaze shift in seen faces, respectively.
Synaptic distribution of the NR1, NR2A and NR2B subunits of the N‐methyl‐d‐aspartate receptor in the rat lumbar spinal cord revealed with an antigen‐unmasking technique
Authors: Nagy Gergely G. , Watanabe Masahiko , Fukaya Masahiro , Todd Andrew J. 
Published: January 2005

AbstractGlutamate is the main excitatory neurotransmitter in the spinal cord and acts on several types of receptor, including N‐methyl‐d‐aspartate (NMDA) receptors, which play an important role in synaptic plasticity and chronic pain. Three families of NMDA receptor subunit have been identified: NR1, NR2 (A–D) and NR3 (A and B). NMDA receptors are heteromeric channels that contain NR1 with at least one NR2 subunit. There is extensive evidence that NMDA receptors are present in spinal cord but little is known about their synaptic distribution. We have used an antigen‐unmasking method involving pepsin treatment to reveal NR1, NR2A and NR2B subunits and have compared their distribution with that of the α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazole propionic acid receptor GluR2 subunit, which is thought to be present at most glutamatergic synapses throughout the spinal cord. After pepsin treatment, punctate labelling was seen with antibodies against each of these subunits. Although NR1 puncta were present throughout the grey matter, NR2A was concentrated in laminae III–IV and NR2B in laminae I–II. The majority of puncta labelled with each NMDA receptor antibody were GluR2‐immunoreactive, which suggests that they were present at synapses, and this was confirmed with electron microscopy for the NR1 and NR2A antibodies. However, many GluR2‐immunoreactive puncta did not show NMDA receptor immunoreactivity. In laminae I–II, most NR2B puncta were also NR1‐immunoreactive and a similar arrangement was found for NR2A/NR1 in laminae III–IV. These results suggest that many, but not all, glutamatergic synapses in the spinal cord possess NMDA receptors and that subunit composition varies in different regions.
Inhibition of tumour necrosis factor‐α by antisense targeting produces immunophenotypical and morphological changes in injury‐activated microglia and macrophages
Authors: Pearse Damien D. , Pereira Francisco C. , Stolyarova Anna , Barakat David J. , Bunge Mary Bartlett 
Published: January 2005

AbstractMicroglia respond in a stereotypical pattern to a diverse array of pathological states. These changes are coupled to morphological and immunophenotypical alterations and the release of a variety of reactive species, trophic factors and cytokines that modify both microglia and their cellular environment. We examined whether a microglial‐produced cytokine, tumour necrosis factor‐α (TNF‐α), was involved in the maintenance of microglial activation after spinal cord injury by selective inhibition using TNF‐α antisense deoxyoligonucleotides (ASOs). Microglia and macrophages harvested from 3 d post‐contused rat spinal cord were large and rounded (86.3 ± 9.6%). They were GSA‐IB4‐positive (GSA‐IB4+) (Griffonia simplicifolia lectin, microglia specific; 94.8 ± 5.1%), strongly OX‐42 positive (raised against a type 3 complement/integrin receptor, CD11b; 78.9 ± 9.1%), ED‐1 positive (a lysosomal marker shown to correlate well with immune cell activation; 97.2 ± 2.6%) and IIA positive (antibody recognizes major histocompatibility complex II; 57.2 ± 5.6%), indicative of fully activated cells, for up to 48 h after plating. These cells also secreted significant amounts of TNF‐α (up to 436 pg/µg total protein, 16 h). Fluoroscein isothiocyanate‐labelled TNF‐α ASOs (5, 50 and 200 nm) added to the culture medium were taken up very efficiently into the cells (> 90% cells) and significantly reduced TNF‐α production by up to 92% (26.5 pg/µg total protein, 16 h, 200 nm TNF‐α ASOs). Furthermore, few of the treated cells at this time were round (5.4 ± 2.7%), having become predominantly spindle shaped (74.9 ± 6.3%) or stellate (21.4 ± 2.7%); immunophenotypically, although all of them remained GSA‐IB4 positive (91.6 ± 6.2%), many were weakly OX‐42 positive and few expressed either ED‐1 (12.9 ± 2.5%) or IIA (19.8 ± 7.4%). Thus, the secretion of TNF‐α early in spinal cord injury may be involved in autoactivating microglia/macrophages. However, at the peak of microglial activation after injury, the activation state of microglia/macrophages is not stable and this process may still be reversible by blocking TNF‐α.
Reconsolidation of fresh, remote, and extinguished fear memory in medaka: old fears don't die
Authors: Eisenberg Mark , Dudai Yadin 
Published: January 2005

AbstractLong‐term fear memory in the medaka fish (Oryzias latipes) regains transient sensitivity to a consolidation blocker immediately after memory reactivation in retrieval (‘reconsolidation’). Here we show that reconsolidation occurs in fresh long‐term memories but not in remote memories, and that the apparent amnesia induced by blockade of reconsolidation can be reinstated by an unpaired reinforcer, a procedure that has no effect on amnesia induced by blockade of consolidation. Extinction memory also undergoes post‐reactivation reconsolidation, the blockade of which exposes the previously acquired fear. Hence in medaka, the process manifested in reconsolidation seems itself to consolidate; moreover, even when the post‐reactivation application of the consolidation blocker is still able to disrupt the memory, the conditioned fear does not seem to go away permanently.
Inhibition of superior colliculus neurons by a GABAergic input from the pretectal nuclear complex in the rat
Authors: Born Gesche , Schmidt Matthias 
Published: January 2005

AbstractThe mammalian pretectal nuclear complex (PNC) is a visual and visuomotor control structure which is strongly connected to other subcortical visual structures. This indicates that the PNC also controls subcortical visual information flow during the execution of various oculomotor programs. A prominent, presumably GABAergic, projection from the PNC targets the superficial grey layer of the superior colliculus (SC), which itself is a central structure for visual information processing necessary for the generation of saccadic eye movements. In order to characterize the pretecto‐tectal projection in vitro, we performed whole‐cell patch‐clamp recordings from SC and PNC neurons in slices obtained from 3–6‐week‐old pigmented rats. Focal glutamate injections into the PNC and electrical PNC stimulation were used to induce postsynaptic responses in SC neurons. Electrical stimulation of the SC allowed electrophysiological identification of PNC neurons that provide the inhibitory pretecto‐tectal input. Only inhibitory postsynaptic currents could be elicited in SC neurons both by pharmacological and by electrical activation of the ipsilateral PNC. Concomitantly, a small number of PNC neurons could be antidromically activated from the ipsilateral SC. Most SC cells postsynaptic to the prectectal input showed the dendritic morphology of wide‐field and narrow‐field cells and are therefore regarded as projection neurons. All inhibitory currents evoked by PNC activation could be completely blocked by bath application of the selective GABAA receptor antagonist bicuculline. Together these results indicate that SC projection neurons receive a direct inhibitory input from the ipsilateral PNC and that this input is mediated by GABAA receptors.
Environmental enrichment enhances auditory takeover of the occipital cortex in anophthalmic mice
Authors: Piché Mathieu , Robert Stéphane , Miceli Dom , Bronchti Gilles 
Published: January 2005

AbstractEnrichment of the environment is an effective means of enhancing neuronal development and plasticity but its effect on the cross‐modal compensation resulting from sensory deprivation has never been investigated. The present study used c‐Fos immunohistochemistry and dextran–biotin neuronal tracing to examine the reorganization of sensory modalities in the brain of anophthalmic mutant mice (ZRDCT/An) raised in either enriched or standard environments. Auditory stimulation was found to elicit strong neuronal activation in thalamic and cortical structures that are normally visual. An important finding was that the latter auditory‐evoked cortical activity was considerably enhanced in blind mice raised in the enriched environment. The axonal tracing study demonstrated auditory inputs from the inferior colliculus to the visual thalamus. This animal model will be useful for understanding neuronal mechanisms underlying some cross‐modal sensory phenomena observed in blind or deaf humans.
Olfactory transduction in ciliated receptor neurons of the Cabinza grunt, Isacia conceptionis (teleostei: haemulidae)
Authors: Schmachtenberg Oliver , Bacigalupo Juan 
Published: January 2005

AbstractThe ciliated receptor neurons of fish olfactory organs are thought to transduce amino acids through a cAMP‐dependent transduction pathway, but direct physiological evidence for this hypothesis remains scarce and is confined to catfish and trout. We investigated olfactory transduction in a marine fish, the Cabinza grunt Isacia conceptionis (Perciformes, Teleostei). The olfactory epithelium was characterized using light and electron microscopy, and isolated ciliated receptor neurons were recorded with the perforated patch‐clamp technique. Cells were stimulated with puffer pipettes containing amino acid odourants, IBMX plus forskolin or 8bromo‐cAMP. All three stimuli triggered transient inward currents at a holding potential of −70 mV and responses with outward‐rectifying current–voltage relationships. The characteristics of the transduction currents induced by each stimulus were similar across cells and indistinguishable within the same cell, supporting the hypothesis of a cAMP pathway mediating transduction of amino acids in ciliated olfactory receptor neurons.
Peripheral ameloblastoma of the gingiva: the importance of diagnosis
Authors: López‐Jornet Pía , Bermejo‐Fenoll Ambrosio 
Published: January 2005

AbstractBackground: Peripheral ameloblastoma is an extremely rare epithelial odontogenic tumor, limited to the soft tissues of the gums or oral mucosa. Although the lesion is benign, it may be locally aggressive.Methods: The present study describes the case of a 31‐year‐old male presenting a firm, symptomless tumor mass of irregular appearance and measuring approximately 12 mm in diameter, located in the distal zone of 4.7.Results: An excision biopsy was performed. The lesion was covered with hyperplastic squamous epithelium, with islets of epithelial cells located at subepithelial level. The cells in the peripheral zone adopted a palisade distribution, and presented the appearance of a lax reticulum at central level. A fibroblastic stroma was observed between the islets. The diagnosis was peripheral ameloblastoma.Conclusions: Although the origin of the lesion remains unclear, it is able to recur and undergo malignant transformation. Consequently, peripheral ameloblastoma should not be viewed as a harmless mass.
Risk determinants of periodontal disease – an analysis of the Study of Health in Pomerania (SHIP 0)
Authors: Kocher T. , Schwahn C. , Gesch D. , Bernhardt O. , John U. , Meisel P. , Baelum V. 
Published: January 2005

AbstractBackground: In this study, risk determinants were determined for periodontal disease in the representative population sample (n=3146) of the Study of Health in Pomerania.Methods: After examining the net random sample (response 69%) and exclusion of edentulous cases and those with missing values, 2595 subjects remained. Using a multivariate, fully adjusted logistic regression, different definitions of “periodontally diseased/healthy” were examined as the dependent variable (extent of attachment loss (AL4 mm, combined AL and tooth loss). The independent variables used were sociodemographic factors (age, gender, income, education), medical factors (systemic diseases, drugs), behavioral factors (regular dental checkup, smoking), and oral factors (presence of supragingival calculus and plaque).Results: The following risk determinants were found for AL: male gender, presence of supragingival plaque and calculus, smoking, low educational level. For the combination of AL and tooth loss, risk determinants were female gender, supragingival plaque, smoking, and low educational level. Consumption of antiallergic medications and regular dental checkups proved to be protective. Smoking was the most influential risk determinant. These parameters explained approximately 43–55% of the variation.Conclusion: These results concur with those of the literature. In order to explain disease status further, host‐response and microbiological factors must also be examined.
The effect of a new toothpaste containing potassium nitrate and triclosan on gingival health, plaque formation and dentine hypersensitivity
Authors: Wara‐aswapati Nawarat , Krongnawakul Duangporn , Jiraviboon Duangporn , Adulyanon Supreda , Karimbux Nadeem , Pitiphat Waranuch 
Published: January 2005

AbstractObjectives: The purpose of this study was to investigate the effect of a new toothpaste containing an antiplaque and antiinflammatory agent (0.3% triclosan), a desensitizing agent (5% potassium nitrate) and an anticaries agent (0.76% sodium monofluorophosphate (SMFP)) on gingival health, plaque formation and dentine hypersensitivity in a 12‐week home study. The efficacy of the test toothpaste was compared with that of a control toothpaste containing 5% potassium nitrate and 0.76% SMFP and a benchmark product containing only 0.76% SMFP.Material and Methods: One hundred and two healthy volunteers, who had a minimum of 20 natural permanent teeth with no probing depth >4 mm and at least one sensitive tooth, participated in this study. Following enrollment, the subjects received a dental prophylaxis and instruction in brushing technique. After a 4‐week pre‐experimental phase, baseline gingival bleeding index (GBI), plaque index (PI) and visual analogue scales (VASs) indicating dentine hypersensitivity levels responding to tactile and air stimuli were assessed. The subjects were then randomly given one of the three toothpastes; test, control, or benchmark toothpaste, and a soft‐filamented toothbrush for home use. The GBI, PI and VASs were re‐examined at weeks 4 and 12.Results: Overall, the GBI scores were significantly reduced compared with baseline in all groups (p<0.01). However, there was no significant difference in GBI score among the three comparison groups. The PI score decreased in the test group and benchmark group from baseline to the end of study, whereas there was no significant change in the control group. Post hoc comparison indicated that the PI score was not statistically different between the three groups. There was a significant difference between the three treatment groups for sensitivity. For both the tactile and air stimuli, the reductions in VAS sensitivity scores for the test group and the control group were significantly greater compared with the benchmark group. Although the sensitivity score for air stimulus decreased more rapidly from baseline to week 4 in the test group, there was no overall difference between the test group and the control group.Conclusions: This study demonstrated that the new toothpaste was effective in reducing dentine hypersensitivity. More studies are needed to further determine the potential interaction between triclosan and potassium nitrate in dentifrices.