bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cluster analysis in individual functional brain images: Some new techniques to enhance the sensitivity of activation detection methods
Authors: Poline Jean‐Baptiste , Mazoyer Bernard 
Published: January 2005

AbstractLow signal‐to‐noise ratio is the fundamental limit of current voxel‐based strategies for detecting activations in functional brain maps. We propose some new techniques to enhance detection sensitivity in the analysis of brain activation maps. These new techniques are: (1) a multi‐filtering strategy; and (2) the use of a hierarchical decomposition. Multi‐filtering is used to optimize detection sensitivity when multiple signals of various sizes are present, while hierarchical decomposition allows selection of activation foci on the basis of their spatial extent and magnitude. Both techniques are combined within a single testing procedure that contrals the overall type I error. This approach shows significantly higher detectioin sensitivity on both simulated and experimental single‐subject datasets. ©1994 Wiley‐Liss, Inc.
Experience‐dependent modifications of hippocampal place cell firing
Authors: Bostock Elizabeth , Muller Robert U. , Kubie John L. 
Published: January 2005

AbstractUnderstanding the empirical rules that regulate alterations of hippocampal firing fields will enhance our understanding of hippocampal function. The current study sought to extend previous research in this area by examining the effect of substituting a new stimulus for a familiar stimulus in a familiar environment. Hippocampal place cells were recorded while rats chased food pellets scattered onto the floor of a cylindrical apparatus with a white cue card affixed to the apparatus wall. Once a place cell had been recorded in the presence of the white card, the white card was replaced by a black card of the same size and shape. The place cell was then recorded in the presence of the black card. Thirty‐six cells were recorded using this procedure. All cells had stable firing fields in the presence of the white card. Both the white and black cards had stimulus control over place cell firing; generally, rotation of either card caused an equal rotation of the firing fields present. When the black card was substituted for the white card, place cells showed time‐variant changes in their spatial firing patterns. The change was such that the spatial firing patterns of the majority of place cells were similar in the presence of the white and black cards during initial black card exposures. During subsequent presentations of the black card, the spatial firing patterns associated with the 2 cards became distinct from each other. Once the differentiation of firing patterns had occurred in a given rat, all place cells subsequently recorded from that rat had different firing patterns in the presence of the white and black cards. The findings are discussed relative to sensory‐, motor‐, attentional‐, and learning‐related interpretations of hippocampal function. It is argued that the time‐variant alteration of place cell firing fields observed following exposure to a novel stimulus in this study reflects an experience‐dependent modification of place cell firing patterns.
Independence of memory functions and emotional behavior: Separate contributions of the hippocampal formation and the amygdala
Authors: Zola‐Morgan Stuart , Squire Larry R. , Clower Robert P. , Alvarez‐Royo Pablo 
Published: January 2005

AbstractStructures and connections in the medial temporal lobe of humans and nonhuman primates have long been recognized as important for normal memory and emotional behavior. The present study investigated memory and emotional behavior in normal monkeys and six groups of monkeys with lesions of the medial temporal lobe. Two groups had damage to the hippocampal formation (or adjacent perirhinal and parahippocampal cortex) but not the amygdaloid complex; two groups had either partial or complete damage to the amygdaloid complex but not the hippocampal formation; and two groups had damage to both the hippocampal formation and the amygdaloid complex. Memory was evaluated with three tasks sensitive to human amnesia: (1) delayed nonmatching to sample; (2) retention of object discriminations; and (3) concurrent discrimination learning. Emotional behavior was assessed by measuring the responsiveness of monkeys to 12 different stimulus situations. Damage to the hippocampal formation or anatomically related cortex impaired memory but did not affect emotional behavior. Partial or complete damage to the amygdaloid complex affected emotional behavior but not memory. These findings show that memory impairment and abnormal emotional behavior are anatomically dissociable and independent effects of damage to the medial temporal lobe.
Protein kinase C activity in the hippocampus following spatial learning tasks in mice
Authors: Noguès Xavier , Micheau Jacques , Jaffard Robert 
Published: January 2005

AbstractProtein kinase C (PKC) is highly concentrated in the hippocampus and is thus a possible neural substrate of learning and memory. This study was designed to determine whether partial acquisition (i.e., the minimal amount of training leading to above‐chance performance) of a spatial discrimination in an eight‐arm radial maze alters hippocampal PKC activity. Mice were sacrificed at different times (5 minutes, 1 hour, 24 hours) after the second learning session, and PKC activity was measured in both cytosolic and membrane fractions of the hippocampus. In order to determine which component of the task was involved in the alterations in enzymatic activity, hippocampal PKC activity was also measured in a group of mice that was allowed to explore the maze freely. Significantly less PKC activity was found in the cytosolic fraction from the trained animals than from the quiet or active control groups. No differences were observed between the quiet and active controls. In contrast, there were no significant between‐groups differences in membrane‐bound PKC activity, although a negative correlation between the membrane‐bound PKC activity and learning scores (accuracy) was noted. These results suggest that hippocampal PKC activity is involved essentially in the associative component of the task. The lack of learning‐induced alterations in membrane‐bound PKC activity and the negative correlation between this enzymatic activity and learning accuracy are discussed.
Topographically specific hippocampal projections target functionally distinct prefrontal areas in the rhesus monkey
Authors: Barbas Helen , Blatt Gene J. 
Published: January 2005

AbstractThe sources of ipsilateral projections from the hippocampal formation, the presubiculum, area 29a‐c, and parasubiculum to medial, orbital, and lateral prefrontal cortices were studied with retrograde tracers in 27 rhesus monkeys. Labeled neurons within the hippocampal formation (CA1, CA1′, prosubiculum, and subiculum) were found rostrally, although some were noted throughout the entire rostrocaudal extent of the hippocampal formation. Most labeled neurons in the hippocampal formation projected to medial prefrontal cortices, followed by orbital areas. In addition, there were differences in the topography of afferent neurons projecting to medial when compared with orbital cortices. Labeled neurons innervating medial cortices were found mainly in the CA1′ and CA1 fields rostrally, but originated in the subicular fields caudally. In contrast, labeled neurons which innervated orbital cortices were considerably more focal, emanating from the same relative position within a field throughout the rostrocaudal extent of the hippocampal formation.In marked contrast to the pattern of projection to medial and orbital prefrontal cortices, lateral prefrontal areas received projections from only a few labeled neurons found mostly in the subicular fields. Lateral prefrontal cortices, lateral prefrontal cortices received the most robust projections from the presubiculum and the supracallosal area 29a‐c. Orbital, and to a lesser extent medial, prefrontal areas received projections from a smaller but significant number of neurons from the presubiculum and area 29a‐c. Only a few labeled neurons were found in the parasubiculum, and most projected to medial prefrontal areas.The results suggest that functionally distinct prefrontal cortices receive projections from different components of the hippocampal region. Medial and orbital prefrontal cortices may have a role in long‐term mnemonic process similar to those associated with the hippocampal formation with which they are linked. Moreover, the preponderance of projection neurons from the hippocampal formation innervating medial when compared with orbital prefrontal areas followed the opposite trend from what we had observed previously for the amygdala (Barbas and De Olmos [1990]) (J Comp Neurol 301:1–23). Thus, the hippocampal formation, associated with mnemonic processes, targets predominantly medial prefrontal cortices, whereas the amygdala, associated with emotional aspects of memory, issues robust projections to orbital limbic cortices. Lateral prefrontal cortices receive robust projections from the presubiculum and area 29a‐c and sparse projections from the hippocampal formation. These findings are consistent with the idea that the role of lateral prefrontal cortices in memory is distinct from that of either medial or orbital cortices. The results suggest that signals from functionally distinct limbic structures to some extent follow parallel pathways to functionally distinct prefrontal cortices. © 1995 Wiley‐Liss, Inc.
Neurotransmitter receptors, endocrine responses and the biological substrates of depression: A review
Authors: Leonard B. E. 
Published: January 2005

AbstractThis review attempts to assess critically the evidence which implicates a disorder of CNS neurotransmission in the aetiology of depression. Evidence for such a disorder has been obtained from changes in neuroendocrine function and in the activity of neurotransmitter receptors located on platelets and lymphocytes of depressed patients. Such studies are important not only because they give an insight into the possible biochemical basis of the illness, but also because they may be used as markers for the onset of depression and of response to treatment. The review concludes with a brief assessment of the change in immune responsiveness which may be associated with the onset of depression. Such studies support the view that the biological changes occurring in depression are not restricted to the brain and therefore open up the possibility that biochemical tests based on analysis of a blood sample may form a useful adjunct to clinical assessment.
Erythrocyte folate before and during treatment with lithium
Authors: Schou Mogens , Mortensen Esper , Vestergaard Per 
Published: January 2005

AbstractWe determined erythrocyte folate in normal subjects (blood donors) as well as in manic‐‐depressive patients before the start of prophylactic lithium treatment and at various times during the treatment. Before treatment the patients' erythrocyte folate was 25 per cent lower and after 6 months of treatment it was 10 per cent lower than the control value. Thereafter patient values and control values did not differ. Lithium treatment accordingly normalised on abnormal folate balance, but it is also possible that lithium in itself may have elevated erythrocyte folate. This is supported by animal data. Rats were given ordinary food and food containing lithium. After eight weeks erythrocyte folate was 27 per cent higher in the lithium‐treated rats than in the controls. Our study does not support the notion that folate supplements are required during lithium therapy.
Lithium longitudinally: An analysis of publication frequencies
Authors: Schou Mogens 
Published: January 2005

AbstractThis paper describes a longitudinal analysis of the frequency of publications over the period 1850–1984 about the biology, the pharmacology and the clinical use of lithium. Distinct phases reflect the various uses of lithium – antimanic, prophylactic and medical – but also reveal concern about unwanted effects, interest in mode of action, and search for valid alternatives.
Lithium and neuroleptics in the management of manic depressive psychosis
Authors: Lowe M. R. , Batchelor D. H. 
Published: January 2005

AbstractThe history of the use of combined lithium and neuroleptics in manic depressive psychosis can be traced from more than 30 studies published over the last 35 years in patients mainly described as suffering from schizo‐affective illness. DSM IIIR identifies one sub‐type of schizo‐affective disorder–schizoaffective disorder bipolar type–which may predict a good response to combined lithium and neuroleptic therapy. Whilst lithium and oral neuroleptics are widely prescribed, little attention has been paid to the use of depot neuroleptics. Haloperidol decanoate, used alone or in combination with lithium for up to 85‐months has proved to be acceptable and effective prophylactic therapy for some unstable manic depressive patients.
Effects of single doses of alprazolam and alcohol alone and in combination on psychological performance
Authors: Bond A. , Silveira J. C. , Lader M. 
Published: January 2005

AbstractThe effects of alprazolam l mg alone and in combination with 0·5 g/kg of alcohol for males and 0·42 g/kg for females were examined on a range of psychological tasks 90 and 180 min post‐drug (45 and 135 min post‐alcohol). Forty‐eight healthy volunteers were assigned randomly to four independent groups who received: alprazolam and placebo drink, alprazolam and alcohol, placebo capsule and alcohol, placebo capsule and placebo drink, respectively. Alprazolam caused subjective sedation, unsteadiness, dizziness and physical tiredness and impaired performance on all tasks. Alcohol caused similar subjective effects but little objective impairment. The effects of the combination were generally no greater than predicted from the sum of the single effects.
The effect of acute alcohol intoxication on psychometric testing and 5‐HT‐induced platelet aggregation in normal subjects; modulatory role of evening primrose oil
Authors: Corbett R. , Meagher J. B. A. , Leonard B. E. 
Published: January 2005

AbstractGroups of university students were exposed acutely to alcohol (100 ml vodka) and their performance in the Bexley Maudsley Automated Psychological Screening Tests (BMAPS) was assessed. Blood samples were also taken to assess platelet aggregation to 5‐HT challenge. After 1 week administration of Evening Primrose Oil (EPO) or placebo under double‐blind conditions the students were re‐assessed. No mean difference was found in the psychometric testing of any of the groups either before or after the administration of EPO; however 5‐HT‐induced platelet aggregation was significantly potentiated in those groups exposed to alcohol, and was further increased in the group receiving EPO. These results suggest that platelet aggregation in response to 5‐HT is more sensitive than psychometric tests commonly used to assess alcoholism in detecting changes due to acute alcohol intoxication.
Effects of price, ‘openness’ of the economy and magnitude of the alternative reinforcer on responding for caffeinated coffee
Authors: Mitchell Suzanne H. , Laurent Carol L. , De Wit Harriet , Zacny James P. 
Published: January 2005

AbstractConsumption of a commodity is influenced by various factors. This experiment examined three factors: unit price, ‘openness’ of the economy, and magnitude of an alternative reinforcer. Subjects earned caffeinated coffee and money by responding on concurrent random‐ratio (RR) schedules. Coffee price was varied by changing the coffee schedule from RR 1·3 to RR 16, while holding the money schedule constant (RR4). Openness of the economy was varied by changing the amount of unearned coffee provided during a 2‐h post‐task period (0, 1·5 or 3 free cups). The magnitude of the alternative reinforcer was varied by allowing subjects to earn an average of $2·00 or $6·00 for responding on the money schedule. Number of responses for coffee and amount of coffee earned varied inversely with the openness of the economy, but were unaffected by the amount of money available. Analysing the demand for coffee as a function of coffee price revealed that coffee was a less elastic commodity when the economy was closed than when it was more open. Within the range of parameters tested here, price of caffeinated coffee and openness of the economy strongly affected responding in humans, whereas the magnitude of an alternative monetary reinforcer had only limited effects.
Fluvoxamine augmentation in chronic schizophrenia: An open exploratory study
Authors: Silver Henry , Kaplan Alla , Kushnir Mina 
Published: January 2005

AbstractThe effect of augmenting standard antipsychotic treatment with the specific serotonergic reuptake inhibitor (SSRI) fluvoxamine was examined in severely disabled chronic schizophrenic inpatients using an open, naturalistic protocol. Fluvoxamine in doses ranging from 25 to 200 mg was added to the antipsychotic medication which was kept constant. Patients were followed for the duration of treatment (to date up to 7·5 months). Assessment included BPRS SANS SAPS and CGI scales (CGI only in the most severely disturbed), and global impressions of occupational and social functioning. Fourteen (74%) of the 19 patients studied showed improvement using 15 per cent change in SANS score or CGI improvement score > = 1 as criterion. The symptom constellation appeared to influence the rate and timing of response. Ten patients experienced exacerbations, some within 2 months of starting treatment, others after 5–6 months. The findings suggest that SSRI augmentation may be effective in severely disabled schizophrenics.
Alteration in the IL‐2 signal peptide affects secretion of proteins in vitro and in vivo
Authors: Zhang Lei , Leng Qixin , Mixson A. James 
Published: January 2005

AbstractBackgroundAlthough hundreds of different signal peptides have now been identified, few studies have examined the factors enabling signal peptides to augment secretion of mature proteins. Signal peptides, located at the N‐terminus of nascent secreted proteins, characteristically have three domains: (1) a basic domain at the N‐terminus, (2) a central hydrophobic core, and (3) a carboxy‐terminal cleavage region. In this study, we investigated whether alterations in the basic and/or the hydrophobic domains of a commonly used signal peptide from interleukin‐2 (IL‐2) affected secretion of two proteins: placental alkaline phosphatase (AP) and endostatin.MethodsA series of modifications in the basic and/or hydrophobic domains of the IL‐2 signal peptide were made by polymerase chain reaction with endostatin or AP plasmids as templates. Transfection of wild‐type or modified IL‐2 signal peptides fused in‐frame with endostatin or AP were done with Superfect in vitro or by the hydrodynamic method in vivo.ResultsIncreasing both the basicity and hydrophobicity of the signal peptide augmented the secretion of AP and endostatin by approximately 2.5‐ and 3.5‐fold, respectively, from MDA‐MB‐435 cells in vitro. Over a range of DNA concentrations and times, the most effective IL‐2 signal peptide increased AP levels in the medium compared to the wild‐type IL‐2 signal peptide. Comparable results from these modified IL‐2 signal peptides were found to increase AP levels in the medium from bovine aortic endothelial cells. Moreover, the combined changes in basic and hydrophobic domains of the IL‐2 signal peptide augmented serum levels of endostatin and placental AP by 3‐fold when the optimal plasmid constructs were injected in vivo.ConclusionsModification of the IL‐2 signal peptide augments protein secretion both in vitro and in vivo. As a result, optimizing the signal peptide should be considered for increasing the therapeutic levels of secreted proteins. Copyright © 2004 John Wiley & Sons, Ltd.
Selective changes in the permeability of the blood‐brain barrier after pharmacological or surgical deafferentation
Authors: Walker Judith Boas , Walker James Paul , Bondy Stephen C. , Purdy Janet 
Published: January 2005

AbstractUnilateral eye removal results in an increased delivery of blood‐borne glucose, norepinephrine, choline, and tyrosine, but not of proline, to the denervated optic lobes. Administration of reserpine to chicks increases penetrance of norepinephrine into the brain but not of tyrosine, choline, or proline. Selective alterations in the permeability of the blood‐brain barrier may represent a mechanism for the modulation of the delivery of critical nutrients to the brain.
A durable chronic unit recording device with movable microelectrode
Authors: Fernáandez‐Bueno Carlos , Lombillo Juan M. , Keene James J. 
Published: January 2005

AbstractThe design of a durable chronic unit recording device with movable microelectrode suitable for cats and monkeys is presented. Sufficiently rugged to remain on cats for weeks during exploration of a single electrode tract, the device also features: choice of stereotaxic coordinates over a large horizontal area at recording time; good stereotaxic precision; capability to hold a single unit for days; excellent insulation between the recording circuit and the animal; and simplicity of design and materials which allows fabrication of numerous devices in one lab.
Regional neurochemical studies on the effect of β,β′ ‐iminodipropionitrile (IDPN) in the rat
Authors: Langlais P. J. , Huang P. C. , Gabay S. 
Published: January 2005

AbstractA permanent hyperkinetic syndrome, characterized by excitation, choreiform head and neck movements and circling, which has led to it being called collectively the “ECC‐syndrome,” is induced in rats by the daily IP administration of β,β′‐iminodipropionitrile (IDPN), 300 mg/kg, for 7 days. The levels of the biogenic amines, norepinephrine (NE), dopamine (DA), serotonin (5‐HT) and its metabolite 5‐hydroxyindoleacetic acid (5‐HIAA), were measured in the striatum, midbrian, medulla, cortex, and cerebellum on the day the syndrome appeared (day 7) and one week later (day 14). The biogenic amine most affected by IDPN administration was 5‐HT. On day 7, striatal 5‐HT level increased and 5‐HIAA levels decreased while in the medulla and midbrain, 5‐HIAA levels increased. On day 14, significant reductions in both 5‐HT, in the midbrain, striatum, and cortex, and 5‐HIAA, in all regions except the cortex, were observed. NE was markedly increased in the medulla, midbrain, and striatum on day 7, whereas on day 14 it was found to be within the normal range in these same regions. With the exception of a slight, but significant, increase in the cortex on day 7, DA levels in all regions were found to be relatively unaffected by IDPN administration on both day 7 and day 14.In an attempt to detect degenerative changes which might be taking place in the brain and which might provide an explanation for the permanency of the behavioral disturbances, the uptake of [3H]‐labeled NE, DA, and 5‐HT into synaptosomal‐rich preparations of striatum and the uptake of NE and 5‐HT into the midbrain area were compared between normal and syndromized rats on both day 7 and day 14. Small changes were observed but they were not statistically significant.The alterations of 5‐HT and 5‐HIAA levels in several regions of the brain under the conditions examined may indicate that IDPN's neurotoxicity primarily affects 5‐HT‐containing neurones. The active membrane transporting system of the nerve endings studied, however, remained relatively intact. This latter finding eliminates the possibility that neuronal degeneration in these areas is responsible for the decreased 5‐HT and 5‐HIAA levels or is the pathology underlying the permanency of the syndrome. These results are evaluated in terms of a possible model for hyperkinetic disorders.