bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regional cerebral glucose metabolism in huntington's disease: A statistical investigation
Authors: Clark Campbell M. , Kremer Barry , Hayden Michael R. 
Published: January 2005

AbstractTo optimize the information obtained in 18fluorodeoxyglucose (FDG) studi8es of human cerebraql metabolism, sources of metabolic variation should be identified and their relevance to clinical pathology and disease course determined. Specifically, although a definitive a priori hypothesis may be postulated in a given study, the sensitivity of a stativity of a statistical procedure for detecting differences may be compromised if the sources of variability in the dependent variable are not fully understood. The purpose of this paper is to illustrate these statements using data derived from normal subjects, patients with symptomatic Huntington's diesase, and patients at risk for Huntington's disease. With respect to positron emission tomography (PET) and FDG, a number of centers have published their findings. Although there is a general consensus that reductions in caudate metabolism are present, there is considerable debate regarding the time in the disease course such reductions occur, the best procedure for measuring such reductions, and the sensitivity of the PET/FDG methodology as a means of monitoring disease progression. The resolution of thses issues is hampered by the large variation among individuals in time of onset and severity of disease course. Because of these properties, statistical examination of regional cerebral metabolism data in Huntington's disease may provide insight into the most efective procedures for maximizing data yield. © 1994 Wiley‐Liss, Inc.
Data analysis paradigms for metabolic‐flow data: Combining neural modeling and functional neuroimaging
Authors: Horwitz Barry 
Published: January 2005

AbstractTwo primary data analysis techniques are used with functional neuroimaging data: the subtraction paradigm and the covariance paradigm. The first is based on the assumption that a brain region participating in a specific task should show altered neural activity (relative to a control task). The second, which is not mutually contradictory with the first, assumes that tasks are mediated by networks of interacting regions and that different tasks involve differences in the pattern of functional connections among brain regions. The neurobiological assumptions governing each paradigm and the kinds of questions each seeks to address are discussed. Illustrations of each technique using positron emission tomographic data of a blood flow study of visual processing are given. The use of neural modeling techniques for analyzing functional neuroimaging data is also discussed, with explicit reference to such systems‐level approaches as structural equation modeling. © 1994 Wiley‐Liss, Inc.
Local circuit synaptic interactions between CA1 pyramidal cells and interneurons in the kainate‐lesioned hyperexcitable hippocampus
Authors: Nakajima S. , Franck J. E. , Bilkey D. , Schwartzkroin P. A. 
Published: January 2005

AbstractFollowing kainate (KA)‐induced lesions of subfield CA3–a lesion relevant to human temporal lobe epilepsy–remaining pyramidal cells in CA1 display synchronous hyperexcitability associated with a loss of synaptic inhibition. Despite this loss, inhibitory interneurons in CA1 remain viable, and the density and function of GABAergic receptors on the CA1 pyramidal cells are maintained at approximately normal levels.To further evaluate inhibition in this system, the authors examined interactions between pyramidal cells and inhibitory interneurons in paired intracellular recordings. Recordings were carried out in rat hippocampal slices 2–4 weeks following bilateral intraventricular KA injections. The frequency of synaptic interactions between CA1 basket cells and pyramidal cells was lower in hyperexcitable slices than in controls; both synapses in the recurrent inhibitory circuit appeared to be involved. No recurrent excitatory interactions were seen between pyramidal cell pairs in lesioned or normal slices.The weakened interconnections between pyramidal cells and interneurons are consistent with the decreased inhibition previously found in the model. Unexpectedly, strong stimulation, which may directly activate local inhibitory circuitry, was effective in reducing hyperexcitability in KA‐lesioned slices. These data suggest that development of recurrent excitatory connections among CA1 hippocampal pyramidal cells contribute little to tissue excitability, and support the hypothesis that a functional uncoupling between inhibitory interneurons and CA1 pyramidal cells is responsible for the seizure‐like activity typical of KA‐lesioned hippocampus. The data are also consistent with the hypothesis that in the KA model, the structural circuitry needed for inhibition in CA1 is maintained, and can be functionally activated by appropriate stimuli.
Long‐term enhancement of CA1 synaptic transmission is due to increased quantal size, not quantal content
Authors: Foster T. C. , McNaughton B. L. 
Published: January 2005

AbstractQuantal components of Schaffer collateral synaptic transmission recorded intracellularly from CA1 pyramidal cells were examined using 2 methods: simultaneous recordings of CA3‐CA1 cell‐pairs, and minimal electrical stimulation in stratum radiatum. Quantal parameters estimated by the method of failures and by a computer algorithm that optimized parameter estimates using deconvolution of background noise were highly correlated. EPSP‐amplitude histograms of CA3‐CA1 cell pairs (N = 10) and minimal electrical stimulation (N = 33) could be adequately described either by Poisson or binomial statistics, or by both, and exhibited similar estimates of unit quantal size (q) and mean quantal content (m). Paired‐pulse stimulation with 50 msec between stimuli resulted in an expected facilitation in the EPSP amplitude and increase in m during the second response, as estimated by noise deconvolution, by the decrease in apparent failures, and by a decrease in the coefficient of variation of the EPSP. Tetanization of the Schaffer collaterals that induced long‐term enhancement (LTE/LTP) of the population response was associated with an average increase in q for minimal‐stimulation responses, with no significant change in any estimate of m. Taken together, these data indicate that, under the present experimental conditions, LTE is expressed as an increase in quantal size, rather than an increase in the number of quanta released per presynaptic impulse. Although this is not definitive evidence for a postsynaptic mechanism, these findings do further restrict the classes of possible presynaptic mechanisms that may be proposed to account for LTE expression.
Hippocampal mossy fibers and swimming navigation in mice: Correlations with size and left‐right asymmetries
Authors: Bernasconi‐Guastalla Sonja , Wolfer David P. , Lipp Hans‐Peter 
Published: January 2005

AbstractIndividual differences in the extent of the infrapyramidal mossy fiber porjection (IIP‐MF) correlate with performance in tasks sensitive to hippocampal lesions, notably two‐way avoidance, radial maze learning, and swimming navigation. Previous studies of swimming navigation suggested that the capacity of reversal learning and measures of directionality might also be related to asymmetries in the distribution of the IIP‐MF. In order to verify these findings, the authors crossed the Collins High‐ and Low‐lateralized mice (known to differ in mossy fiber morphology and brain asymmetries) and obtained a F2‐generation characterized by strong individual differences in these traits. Twenty‐three (13 females, 10 males) mice were tested during 3 days for acquisition of swimming navigation (16 trials) toward a central platform, and during two days (12 trials) for their capacity of reversal learning toward a shifted platform. Morphometry of Timm‐stained hippocampi revealed several, partially independent correlations: Larger IIP‐MF projections were associated with prolonged crossing over the former platform position during the entire reversal learning; larger IIP‐MF projections on the left were correlated with more precise crossing of the former platform position during the first 45 seconds of reversal learning; both extent and asymmetry of IIP‐MF correlated positively with overnight improvement of reversal learning; the size of the entire mossy fiber projection (CA4, suprapyramidal and IIP‐MF) correlated positively with the time spent in the platform quadrant and measures of initial orientation during acquisition of the task; and the mice showed an ipsilateral turning bias (spin) toward the side with the larger mossy fiber projection. The authors conclude that an intact hippocampus mediates differential processes underlying swimming navigation, and that left and right subfields may have differential functions.
Electrophysiological effects of mu‐selective opioids on hilar neurons in the hippocampus in vivo
Authors: Mayer Joseph H. , Henriksen Steven J. 
Published: January 2005

AbstractAlthough mu‐selective opioids have been shown to produce dramatic effects on neurons within the CA1 and dentate regions of the rat hippocampus, little is known regarding their effects on neurons within the hilus, a region of potential importance in several disease states. We studied the neurophysiologic responses of hilar neurons recorded extracellularly to electrophoretic [D‐Ala2, NMe‐Phe4, Gly‐ol]‐enkephalin (DAMGO) and systemic morphine (MS) in anesthetized rats. We found that hilar cells could be readily divided into two categories, based on their pattern of spontaneous activity and response to perforant path stimulation. Cells that discharged in a bursting‐type pattern formed a homogeneous group electrophysiologically. The response of these cells to opioids was dependent on route of administration, with the spontaneous activity of all cells tested increasing following electrophoretically administered DAMGO, and remaining unchanged in response to systemic MS. Cells that discharged in a non‐bursting pattern showed some electrophysiologic variation, as well as some differential response to opioids. However, the spontaneous activity in the majority of non‐bursting cells increased following electrophoretic administration of DAMGO. In these cells, MS produced similar, although usually less dramatic, effects. Comparison with intracellular data suggests that the bursting cells in our study correlate most closely with hilar “mossy cells,” while the non‐bursting action potentials were recorded from other cells, primarily putative interneurons. We conclude that mu‐selective opioids produce excitation of mossy cells, probably through an indirect mechanism, with the primary site of action occurring on cells in the granule cell layer. This regional excitation may help to mediate the effects of locally administered mu‐selective opioids within the dentate gyrus. © 1995 Wiley‐Liss, Inc.
Similarities vs. differences in place learning and circadian activity in rats after fimbria‐fornix section or ibotenate removal of hippocampal cells
Authors: Whishaw Ian Q. , Jarrard Leonard E. 
Published: January 2005

AbstractDamage to either the fimbria‐fornix or to the hippocampus can produce a deficit in spatial behavior and change in locomotor activity but the extent to which the two kinds of damage are comparable is not known. Here we contrasted the effects of cathodal sections of the fimbria‐fornix with ibotenic acid lesions of the cells of the hippocampus (Ammon's horn and the dentate gyrus) on place learning in a swimming pool and on circadian activity. Rats in both ablation groups were impaired relative to control rats in learning a single place response but they did acquire the response as measured by swim latencies, errors, and by enhanced searching on probe trials. They were also more active than the control group on the test of activity. Nevertheless, the fimbria‐fornix group was initially more impaired on learning and was more active than the hippocampal group. Analysis of the strategies used in learning indicated that the lesion groups were very similar to each other but different from the control group especially in that at asymptotic performance, rats in both lesion groups made rather tight loops as they swam toward the platform. This strategy likely contributed to the greater proportion of time they spent swimming in the correct quadrant on the subsequent probe trial. These findings confirm that rats with fimbria‐fornix or hippocampal damage display impairments in place learning and are hyperactive but also show that there are lesion differences. The results are discussed with respect to the relative effectiveness of the lesions and the possibility that fibers in the fimbria‐fornix may mediate some functions that are not attributable to the hippocampus. © 1995 Wiley‐Liss, Inc.
Serum and cerebrospinal fluid levels of fluphenazine–relationship to treatment response in schizophrenic patients
Authors: Rimón Ranan , Kampman Reima , Laru‐Sompa Raili , Wiles D. H. 
Published: January 2005

AbstractSerum and cerebrospinal fluid (CSF) concentrations of fluphenazine (FPZ) were measured during nine weeks of FPZ medication in 28 patients with acute symptoms of schizophrenia. A significant correlation was found between the serum and CSF FPZ values (r = 0·70, p < 0·001) throughout the entire study. Patients exhibiting marked clinical improvement (MCI) had higher levels of serum and CSF FPZ than did patients showing only slight clinical improvement (SCI) or those with no treatment response (NTR). The differences between the MCI and the NTR group were at most observation points statistically significant (p < 0·05). The figures of the SCI group formed an intermediate curve between the serum and CSF FPZ curve of the MCI and the NTR patients.The serum and the CSF levels of FPZ were not significantly related to such variables as age, sex, duration of illness, number of previous psychotic episodes, or subtype of schizophrenia.
The effects of single and repeated doses of oral scopolamine, cinnarizine, and placebo upon psychological performance and physiological functioning
Authors: Parrott A. C. , Golding J. F. , Pethybridge R. J. 
Published: January 2005

AbstractThe present study was one in a series in the Institute of Naval Medicine's Motion Illness Project. A battery of psychological performance tests (producing 26 indices of mental and hand‐‐eye co‐ordination), together with visual near fixation point, resting heart rate and a self‐rated feeling state questionnaire, were used to compare the effects of thrice‐daily oral doses of scopolamine (0.6 mg), cinnarizine (30 mg) and a lactose placebo in a double‐blind crossover trial on 12 healthy male volunteers. Measurements were made 1–2 and 5–6 h after the initial dose, then the next day following the last successive dose (1–2 and 5–6 h after the fourth dose; or 25–26 and 29–30 h after the initial dose). Scopolamine demonstrated clear physiological effects, with reduced heart rate from the first oral dose onwards, and visual near‐point values increasingly distant over successive doeses. Cinnarizine did not produce significant physiological changes. Neither drug produced significant effects on subjective mood. Significant ANOVA drug effects or drug × time interaction effects were present with five out of the 26 performance variables: logical reasoning error, memory word‐recall errors; continuous four choice reaction time; concept identification time; SERS task commission error. However only two of these (memory error, four choice reaction time) demonstrated patterns of effect which were considered to be attributable to the drugs. Both cinnarizine and scopolamine impaired memory error and four choice reaction time. Only for visual near‐point with scopolamine was there evidence that repeated dosing led to increasing physiological/mental performance effects.
Sulpiride in negative schizophrenia: A placebo‐controlled double‐blind assessment
Authors: Soni S. D. , Mallik A. , Schiff A. A. 
Published: January 2005

AbstractTwenty‐four chronic schizophrenic long‐stay hospital patients were identified, who had not received neuroleptic drugs for 8–30 (average 8 months) and met or exceeded a minimum criterion of severity of negative symptoms. They were rendomly alocated to either sulpiride 200 mg twice daily or matching placebo, on a double‐blind basis for 12 weeks. The results showed that low‐dose sulpiride was significantly better than placebo in relation to improvements in negative symptoms. The changes in social behaviour were complex and not obviously related to symptom improvement; exhibited abnormal behaviour, a major factor in preventing successful return to the community, consistently improved only on the active drug.
Significantly increased urinary free cortisol excretion in melancholic depressed females during L‐tryptophan loading
Authors: Maes M. , Minner B. , Suy E. , D'hondt P. 
Published: January 2005

AbstractTo assess the status of serotonergic neurotransmission in depressed females, the authors examined the excretion of free cortisol in 24 h urine both before and after administering 5 g L‐tryptophan (L‐TRP) orally. The depressed patients were classified according to the DSM‐III into minor, simple major and major depression with melancholia. We found a significant, enhacing effect for L‐TRP on urinary free cortisol (UFC) excretion. The absolute increments in UFC induced by L‐TRP were significantly higher in melancholic females as compared to minor and simple major depressives. We found no differences among the DSM‐III groups in the availability of L‐TRP to the brain, 9 h after L‐TRP administration.
Possible mechanisms for the presumed interaction between lithium and neuroleptics
Authors: Von Knorring L. 
Published: January 2005

AbstractAll the case reports describing neurotoxicity following combined lithium and haloperidol treatment could well be consistent with lithium toxicity alone. Pharmacokinetic and pharmacological explanations are considered. The effects of co‐administered lithium and neroleptic treatment on fluid balance mechanisms and intracellular lithium concentrations may be associated with increased lithium toxicity.
Clinical and functional correlates of a dopamine D3 receptor polymorphism
Authors: Crocq Marc Antoine , Duval Fabrice , Mayerova Antonia , Sokoloff Pierre , Mokrani Marie Claude , Macher Jean Paul 
Published: January 2005

AbstractThis is a review of our research on dopamine receptor D3 (DRD3) gene polymorphism in psychiatric patients. We found that heterozygosity at a diallelic Ball polymorphic site in the first exon of the DRD3 gene was associated with schizophrenia, as did another group (Mant et al., 1994). However others did not reproduce our findings and raised doubts about a possible role of the DRD3 in schizophrenia. More recently, we found that homozygosity for allele 2 at the same site was associated with lower cortisol and ACTH responses to apomorphine. We had also previously reported lower ACTH and cortisol responses to apomorphine in paranoid schizophrenics compared to controls (Mokrani et al., in press). This suggests that DRD3 polymorphisms might be associated with functional differences that could secondarily influence the expression of schizophrenia, in spite of the lack of clear association with schizophrenia. More generally, classical association studies may be limited in their power to prove or disprove minor gene effects in schizophrenia because the disorder is heterogeneous and various genes may have additive effects in different patients. Biological measures that are closer to gene effects may be a better way to test candidate genes than the association with a complex clinical phenotype.
Hypophagic, endocrine and subjective responses to m‐chlorophenylpiperazine in healthy men and women
Authors: Cowen P. J. , Sargent P. A. , Williams C. , Goodall E. M. , Orlikov A. B. 
Published: January 2005

AbstractWe studied the effect of the 5‐HT receptor agonist, m‐chlorophenylpiperazine (mCPP) (0.4 mg orally), on food intake, plasma prolactin and subjective state in 24 healthy male and female volunteers, using a double‐blind, placebo‐controlled design. mCPP lowered food intake, and increased plasma prolactin to the same extent in both sexes. Increased anxiety ratings, however, occurred more in females. Other mCPP‐induced subjective changes in nausea, light‐headedness and hunger did not distinguish the sexes. There was no significant correlation between the decrease in food intake produced by mCPP and any of the subjective ratings. Overall, the data indicate that mCPP produces significant hypophagia in both men and women. The greater anxiogenic effect of mCPP in female subjects is of interest in view of the increased prevalence of clinical anxiety disorders in women.
High dose tertiary amine tricyclic antidepressants in the treatment of severe refractory depression: The central role of plasma concentration estimations
Authors: Hodgkiss A. D. , McCarthy P. T. , Sulke A. N. , Bridges P. K. 
Published: January 2005

AbstractThe relationships between dosage, plasma concentration, antidepressant response and toxicity were investigated in 24 highly selected patients with severe, refractory major depression who were prescribed amitriptyline, clompramine or dothiepin at high dosage (150–525 mg/day), usually in combination with lithium or other psychotropics. of serious adverse effects 83 per cent were encountered when tricyclic antidepressant (TCA) plasma concentrations exceeded 400 mcg/1. Therapeutic drug monitoring of high dose TCAs is useful in minimizing the risk of toxicity and in revealing poor compliance, undertreatment and pharmacokinetic interactions which can mitigate against drug efficacy. The value of carbamazepine in the management of refractory depression in the context of unipolar affective disorder is put into question.
Nogo signaling and non‐physical injury‐induced nervous system pathology
Authors: Teng Felicia Yu Hsuan , Tang Bor Luen 
Published: January 2005

AbstractThe Nogo gene products were described first as myelin‐associated inhibitors that prevent neuronal regeneration upon injury. Recent findings have also implicated Nogo in several neuronal pathologies that are not induced by physical injury. Nogo‐A may be an important determinant of autoimmune demyelinating diseases, as active immunization with Nogo‐A fragments attenuates the symptoms of experimental autoimmune encephalomyelitis (EAE). Nogo‐A levels are elevated markedly in hippocampal neurons of patients with temporal lobe epilepsy (TLE), in brain and muscle of patients with amyotrophic lateral sclerosis (ALS), and in schizophrenic patients. Concrete evidence for a direct role of Nogo‐A in the latter neuropathies is not yet available, but such a role is logically in line with new findings associated with localization of Nogo‐A and Nogo–Nogo‐66 receptor (NgR)‐mediated signaling. We speculate on possible linkages between the effect of aberrant elevation of Nogo levels and the signaling consequences that could lead to nervous system pathology. © 2004 Wiley‐Liss, Inc.